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* [PATCH 0/4] trace2: load trace2 settings from system config
@ 2019-03-28 13:30 Jeff Hostetler via GitGitGadget
  2019-03-28 13:30 ` [PATCH 1/4] trace2: refactor setting process starting time Jeff Hostetler via GitGitGadget
                   ` (4 more replies)
  0 siblings, 5 replies; 68+ messages in thread
From: Jeff Hostetler via GitGitGadget @ 2019-03-28 13:30 UTC (permalink / raw)
  To: git; +Cc: gitster, peff, jrnieder, steadmon, avarab, Junio C Hamano

Teach git to load default Trace2 settings from the system config (usually
"/etc/gitconfig"). The existing GIT_TR2_* environment variables can be used
to override the new system defaults. It also includes a little startup
refactoring.

Note: I found interactive testing of this feature to be awkward on some
platforms because of the use of prefix- or runtime-prefix-relative locations
for the system configuration. It was easy to accidentally use an officially
installed version of git to set a system config variable in the official
system config directory; and then when testing with the test version of git,
that value would not be seen because it was looking for the system config
file in a different directory.

Jeff Hostetler (4):
  trace2: refactor setting process starting time
  trace2: add absolute elapsed time to start event
  trace2: find exec-dir before trace2 initialization
  trace2: use system config for default trace2 settings

 Documentation/technical/api-trace2.txt |  54 +++++++++--
 Makefile                               |   1 +
 common-main.c                          |   6 +-
 compat/mingw.c                         |   2 +
 t/t0210-trace2-normal.sh               |  41 +++++++-
 t/t0211-trace2-perf.sh                 |  53 ++++++++---
 t/t0212-trace2-event.sh                |  52 +++++++++-
 trace2.c                               |  19 +++-
 trace2.h                               |  24 ++++-
 trace2/tr2_cfg.c                       |   7 +-
 trace2/tr2_dst.c                       |  24 ++---
 trace2/tr2_dst.h                       |   3 +-
 trace2/tr2_sysenv.c                    | 125 +++++++++++++++++++++++++
 trace2/tr2_sysenv.h                    |  36 +++++++
 trace2/tr2_tgt.h                       |   1 +
 trace2/tr2_tgt_event.c                 |  24 ++---
 trace2/tr2_tgt_normal.c                |  13 +--
 trace2/tr2_tgt_perf.c                  |  17 ++--
 trace2/tr2_tls.c                       |  38 +++++---
 trace2/tr2_tls.h                       |   8 +-
 20 files changed, 455 insertions(+), 93 deletions(-)
 create mode 100644 trace2/tr2_sysenv.c
 create mode 100644 trace2/tr2_sysenv.h


base-commit: 041f5ea1cf987a4068ef5f39ba0a09be85952064
Published-As: https://github.com/gitgitgadget/git/releases/tag/pr-169%2Fjeffhostetler%2Fcore-tr2-startup-and-sysenv-v1
Fetch-It-Via: git fetch https://github.com/gitgitgadget/git pr-169/jeffhostetler/core-tr2-startup-and-sysenv-v1
Pull-Request: https://github.com/gitgitgadget/git/pull/169
-- 
gitgitgadget

^ permalink raw reply	[flat|nested] 68+ messages in thread

* [PATCH 1/4] trace2: refactor setting process starting time
  2019-03-28 13:30 [PATCH 0/4] trace2: load trace2 settings from system config Jeff Hostetler via GitGitGadget
@ 2019-03-28 13:30 ` Jeff Hostetler via GitGitGadget
  2019-03-28 13:31 ` [PATCH 2/4] trace2: add absolute elapsed time to start event Jeff Hostetler via GitGitGadget
                   ` (3 subsequent siblings)
  4 siblings, 0 replies; 68+ messages in thread
From: Jeff Hostetler via GitGitGadget @ 2019-03-28 13:30 UTC (permalink / raw)
  To: git
  Cc: gitster, peff, jrnieder, steadmon, avarab, Junio C Hamano,
	Jeff Hostetler

From: Jeff Hostetler <jeffhost@microsoft.com>

Create trace2_initialize_clock() and call from main() to capture
process start time in isolation and before other sub-systems are
ready.

Signed-off-by: Jeff Hostetler <jeffhost@microsoft.com>
---
 Documentation/technical/api-trace2.txt | 12 ++++++--
 common-main.c                          |  2 ++
 compat/mingw.c                         |  2 ++
 trace2.c                               |  7 ++++-
 trace2.h                               | 17 ++++++++++++
 trace2/tr2_tls.c                       | 38 ++++++++++++++++----------
 trace2/tr2_tls.h                       |  8 +++++-
 7 files changed, 67 insertions(+), 19 deletions(-)

diff --git a/Documentation/technical/api-trace2.txt b/Documentation/technical/api-trace2.txt
index 2de565fa3d..f37fccf1da 100644
--- a/Documentation/technical/api-trace2.txt
+++ b/Documentation/technical/api-trace2.txt
@@ -160,17 +160,23 @@ purposes.
 
 These are concerned with the lifetime of the overall git process.
 
+`void trace2_initialize_clock()`::
+
+	Initialize the Trace2 start clock and nothing else.  This should
+	be called at the very top of main() to capture the process start
+	time and reduce startup order dependencies.
+
 `void trace2_initialize()`::
 
 	Determines if any Trace2 Targets should be enabled and
-	initializes the Trace2 facility.  This includes starting the
-	elapsed time clocks and thread local storage (TLS).
+	initializes the Trace2 facility.  This includes setting up the
+	Trace2 thread local storage (TLS).
 +
 This function emits a "version" message containing the version of git
 and the Trace2 protocol.
 +
 This function should be called from `main()` as early as possible in
-the life of the process.
+the life of the process after essential process initialization.
 
 `int trace2_is_enabled()`::
 
diff --git a/common-main.c b/common-main.c
index d484aec209..6137af0e63 100644
--- a/common-main.c
+++ b/common-main.c
@@ -27,6 +27,8 @@ int main(int argc, const char **argv)
 {
 	int result;
 
+	trace2_initialize_clock();
+
 	/*
 	 * Always open file descriptors 0/1/2 to avoid clobbering files
 	 * in die().  It also avoids messing up when the pipes are dup'ed
diff --git a/compat/mingw.c b/compat/mingw.c
index 6b04514cdc..a2f74aca6a 100644
--- a/compat/mingw.c
+++ b/compat/mingw.c
@@ -2569,6 +2569,8 @@ void mingw_startup(void)
 	wchar_t **wenv, **wargv;
 	_startupinfo si;
 
+	trace2_initialize_clock();
+
 	maybe_redirect_std_handles();
 
 	/* get wide char arguments and environment */
diff --git a/trace2.c b/trace2.c
index ccccd4ef09..6dd51e6aa5 100644
--- a/trace2.c
+++ b/trace2.c
@@ -142,6 +142,11 @@ static void tr2main_signal_handler(int signo)
 	raise(signo);
 }
 
+void trace2_initialize_clock(void)
+{
+	tr2tls_start_process_clock();
+}
+
 void trace2_initialize_fl(const char *file, int line)
 {
 	struct tr2_tgt *tgt_j;
@@ -428,7 +433,7 @@ void trace2_thread_start_fl(const char *file, int line, const char *thread_name)
 	us_now = getnanotime() / 1000;
 	us_elapsed_absolute = tr2tls_absolute_elapsed(us_now);
 
-	tr2tls_create_self(thread_name);
+	tr2tls_create_self(thread_name, us_now);
 
 	for_each_wanted_builtin (j, tgt_j)
 		if (tgt_j->pfn_thread_start_fl)
diff --git a/trace2.h b/trace2.h
index ae5020d0e6..8f89e70c44 100644
--- a/trace2.h
+++ b/trace2.h
@@ -19,6 +19,23 @@ struct json_writer;
  * [] trace2_printf*    -- legacy trace[1] messages.
  */
 
+/*
+ * Initialize the TRACE2 clock and do nothing else, in particular
+ * no mallocs, no system inspection, and no environment inspection.
+ *
+ * This should be called at the very top of main() to capture the
+ * process start time.  This is intended to reduce chicken-n-egg
+ * bootstrap pressure.
+ *
+ * It is safe to call this more than once.  This allows capturing
+ * absolute startup costs on Windows which uses a little trickery
+ * to do setup work before common-main.c:main() is called.
+ *
+ * The main trace2_initialize_fl() may be called a little later
+ * after more infrastructure is established.
+ */
+void trace2_initialize_clock(void);
+
 /*
  * Initialize TRACE2 tracing facility if any of the builtin TRACE2
  * targets are enabled in the environment.  Emits a 'version' event.
diff --git a/trace2/tr2_tls.c b/trace2/tr2_tls.c
index 8e65b0361d..31fb529f93 100644
--- a/trace2/tr2_tls.c
+++ b/trace2/tr2_tls.c
@@ -10,16 +10,30 @@
 #define TR2_REGION_NESTING_INITIAL_SIZE (100)
 
 static struct tr2tls_thread_ctx *tr2tls_thread_main;
-static uint64_t tr2tls_us_start_main;
+static uint64_t tr2tls_us_start_process;
 
 static pthread_mutex_t tr2tls_mutex;
 static pthread_key_t tr2tls_key;
 
 static int tr2_next_thread_id; /* modify under lock */
 
-struct tr2tls_thread_ctx *tr2tls_create_self(const char *thread_name)
+void tr2tls_start_process_clock(void)
+{
+	if (tr2tls_us_start_process)
+		return;
+
+	/*
+	 * Keep the absolute start time of the process (i.e. the main
+	 * process) in a fixed variable since other threads need to
+	 * access it.  This allows them to do that without a lock on
+	 * main thread's array data (because of reallocs).
+	 */
+	tr2tls_us_start_process = getnanotime() / 1000;
+}
+
+struct tr2tls_thread_ctx *tr2tls_create_self(const char *thread_name,
+					     uint64_t us_thread_start)
 {
-	uint64_t us_now = getnanotime() / 1000;
 	struct tr2tls_thread_ctx *ctx = xcalloc(1, sizeof(*ctx));
 
 	/*
@@ -29,7 +43,7 @@ struct tr2tls_thread_ctx *tr2tls_create_self(const char *thread_name)
 	 */
 	ctx->alloc = TR2_REGION_NESTING_INITIAL_SIZE;
 	ctx->array_us_start = (uint64_t *)xcalloc(ctx->alloc, sizeof(uint64_t));
-	ctx->array_us_start[ctx->nr_open_regions++] = us_now;
+	ctx->array_us_start[ctx->nr_open_regions++] = us_thread_start;
 
 	ctx->thread_id = tr2tls_locked_increment(&tr2_next_thread_id);
 
@@ -55,7 +69,7 @@ struct tr2tls_thread_ctx *tr2tls_get_self(void)
 	 * here and silently continue.
 	 */
 	if (!ctx)
-		ctx = tr2tls_create_self("unknown");
+		ctx = tr2tls_create_self("unknown", getnanotime() / 1000);
 
 	return ctx;
 }
@@ -124,22 +138,18 @@ uint64_t tr2tls_absolute_elapsed(uint64_t us)
 	if (!tr2tls_thread_main)
 		return 0;
 
-	return us - tr2tls_us_start_main;
+	return us - tr2tls_us_start_process;
 }
 
 void tr2tls_init(void)
 {
+	tr2tls_start_process_clock();
+
 	pthread_key_create(&tr2tls_key, NULL);
 	init_recursive_mutex(&tr2tls_mutex);
 
-	tr2tls_thread_main = tr2tls_create_self("main");
-	/*
-	 * Keep a copy of the absolute start time of the main thread
-	 * in a fixed variable since other threads need to access it.
-	 * This also eliminates the need to lock accesses to the main
-	 * thread's array (because of reallocs).
-	 */
-	tr2tls_us_start_main = tr2tls_thread_main->array_us_start[0];
+	tr2tls_thread_main = tr2tls_create_self("main",
+						tr2tls_us_start_process);
 }
 
 void tr2tls_release(void)
diff --git a/trace2/tr2_tls.h b/trace2/tr2_tls.h
index bb80e3f8e7..b1e327a928 100644
--- a/trace2/tr2_tls.h
+++ b/trace2/tr2_tls.h
@@ -31,7 +31,8 @@ struct tr2tls_thread_ctx {
  * In this and all following functions the term "self" refers to the
  * current thread.
  */
-struct tr2tls_thread_ctx *tr2tls_create_self(const char *thread_name);
+struct tr2tls_thread_ctx *tr2tls_create_self(const char *thread_name,
+					     uint64_t us_thread_start);
 
 /*
  * Get our TLS data.
@@ -94,4 +95,9 @@ void tr2tls_release(void);
  */
 int tr2tls_locked_increment(int *p);
 
+/*
+ * Capture the process start time and do nothing else.
+ */
+void tr2tls_start_process_clock(void);
+
 #endif /* TR2_TLS_H */
-- 
gitgitgadget


^ permalink raw reply	[flat|nested] 68+ messages in thread

* [PATCH 2/4] trace2: add absolute elapsed time to start event
  2019-03-28 13:30 [PATCH 0/4] trace2: load trace2 settings from system config Jeff Hostetler via GitGitGadget
  2019-03-28 13:30 ` [PATCH 1/4] trace2: refactor setting process starting time Jeff Hostetler via GitGitGadget
@ 2019-03-28 13:31 ` Jeff Hostetler via GitGitGadget
  2019-03-28 13:31 ` [PATCH 3/4] trace2: find exec-dir before trace2 initialization Jeff Hostetler via GitGitGadget
                   ` (2 subsequent siblings)
  4 siblings, 0 replies; 68+ messages in thread
From: Jeff Hostetler via GitGitGadget @ 2019-03-28 13:31 UTC (permalink / raw)
  To: git
  Cc: gitster, peff, jrnieder, steadmon, avarab, Junio C Hamano,
	Jeff Hostetler

From: Jeff Hostetler <jeffhost@microsoft.com>

Add elapsed process time to "start" event to measure
the performance of early process startup.

Signed-off-by: Jeff Hostetler <jeffhost@microsoft.com>
---
 Documentation/technical/api-trace2.txt | 11 ++++++-----
 t/t0211-trace2-perf.sh                 | 12 ++++++------
 trace2.c                               |  8 +++++++-
 trace2/tr2_tgt.h                       |  1 +
 trace2/tr2_tgt_event.c                 |  5 ++++-
 trace2/tr2_tgt_normal.c                |  3 ++-
 trace2/tr2_tgt_perf.c                  |  7 ++++---
 7 files changed, 30 insertions(+), 17 deletions(-)

diff --git a/Documentation/technical/api-trace2.txt b/Documentation/technical/api-trace2.txt
index f37fccf1da..baaa1153bb 100644
--- a/Documentation/technical/api-trace2.txt
+++ b/Documentation/technical/api-trace2.txt
@@ -60,7 +60,7 @@ git version 2.20.1.155.g426c96fcdb
 ------------
 $ cat ~/log.perf
 12:28:42.620675 common-main.c:38                  | d0 | main                     | version      |     |           |           |            | 2.20.1.155.g426c96fcdb
-12:28:42.621001 common-main.c:39                  | d0 | main                     | start        |     |           |           |            | git version
+12:28:42.621001 common-main.c:39                  | d0 | main                     | start        |     |  0.001173 |           |            | git version
 12:28:42.621111 git.c:432                         | d0 | main                     | cmd_name     |     |           |           |            | version (version)
 12:28:42.621225 git.c:662                         | d0 | main                     | exit         |     |  0.001227 |           |            | code:0
 12:28:42.621259 trace2/tr2_tgt_perf.c:211         | d0 | main                     | atexit       |     |  0.001265 |           |            | code:0
@@ -79,7 +79,7 @@ git version 2.20.1.155.g426c96fcdb
 ------------
 $ cat ~/log.event
 {"event":"version","sid":"1547659722619736-11614","thread":"main","time":"2019-01-16 17:28:42.620713","file":"common-main.c","line":38,"evt":"1","exe":"2.20.1.155.g426c96fcdb"}
-{"event":"start","sid":"1547659722619736-11614","thread":"main","time":"2019-01-16 17:28:42.621027","file":"common-main.c","line":39,"argv":["git","version"]}
+{"event":"start","sid":"1547659722619736-11614","thread":"main","time":"2019-01-16 17:28:42.621027","file":"common-main.c","line":39,"t_abs":0.001173,"argv":["git","version"]}
 {"event":"cmd_name","sid":"1547659722619736-11614","thread":"main","time":"2019-01-16 17:28:42.621122","file":"git.c","line":432,"name":"version","hierarchy":"version"}
 {"event":"exit","sid":"1547659722619736-11614","thread":"main","time":"2019-01-16 17:28:42.621236","file":"git.c","line":662,"t_abs":0.001227,"code":0}
 {"event":"atexit","sid":"1547659722619736-11614","thread":"main","time":"2019-01-16 17:28:42.621268","file":"trace2/tr2_tgt_event.c","line":163,"t_abs":0.001265,"code":0}
@@ -601,6 +601,7 @@ from all events and the `time` field is only present on the "start" and
 {
 	"event":"start",
 	...
+	"t_abs":0.001227, # elapsed time in seconds
 	"argv":["git","version"]
 }
 ------------
@@ -1118,7 +1119,7 @@ $ git status
 
 $ cat ~/log.perf
 d0 | main                     | version      |     |           |           |            | 2.20.1.160.g5676107ecd.dirty
-d0 | main                     | start        |     |           |           |            | git status
+d0 | main                     | start        |     |  0.001173 |           |            | git status
 d0 | main                     | def_repo     | r1  |           |           |            | worktree:/Users/jeffhost/work/gfw
 d0 | main                     | cmd_name     |     |           |           |            | status (status)
 ...
@@ -1163,7 +1164,7 @@ $ git status
 ...
 $ cat ~/log.perf
 d0 | main                     | version      |     |           |           |            | 2.20.1.162.gb4ccea44db.dirty
-d0 | main                     | start        |     |           |           |            | git status
+d0 | main                     | start        |     |  0.001173 |           |            | git status
 d0 | main                     | def_repo     | r1  |           |           |            | worktree:/Users/jeffhost/work/gfw
 d0 | main                     | cmd_name     |     |           |           |            | status (status)
 ...
@@ -1219,7 +1220,7 @@ $ git status
 ...
 $ cat ~/log.perf
 d0 | main                     | version      |     |           |           |            | 2.20.1.156.gf9916ae094.dirty
-d0 | main                     | start        |     |           |           |            | git status
+d0 | main                     | start        |     |  0.001173 |           |            | git status
 d0 | main                     | def_repo     | r1  |           |           |            | worktree:/Users/jeffhost/work/gfw
 d0 | main                     | cmd_name     |     |           |           |            | status (status)
 d0 | main                     | region_enter | r1  |  0.001791 |           | index      | label:do_read_index .git/index
diff --git a/t/t0211-trace2-perf.sh b/t/t0211-trace2-perf.sh
index 953e2f7847..c9694b29f7 100755
--- a/t/t0211-trace2-perf.sh
+++ b/t/t0211-trace2-perf.sh
@@ -50,7 +50,7 @@ test_expect_success 'perf stream, return code 0' '
 	perl "$TEST_DIRECTORY/t0211/scrub_perf.perl" <trace.perf >actual &&
 	cat >expect <<-EOF &&
 		d0|main|version|||||$V
-		d0|main|start|||||_EXE_ trace2 001return 0
+		d0|main|start||_T_ABS_|||_EXE_ trace2 001return 0
 		d0|main|cmd_name|||||trace2 (trace2)
 		d0|main|exit||_T_ABS_|||code:0
 		d0|main|atexit||_T_ABS_|||code:0
@@ -64,7 +64,7 @@ test_expect_success 'perf stream, return code 1' '
 	perl "$TEST_DIRECTORY/t0211/scrub_perf.perl" <trace.perf >actual &&
 	cat >expect <<-EOF &&
 		d0|main|version|||||$V
-		d0|main|start|||||_EXE_ trace2 001return 1
+		d0|main|start||_T_ABS_|||_EXE_ trace2 001return 1
 		d0|main|cmd_name|||||trace2 (trace2)
 		d0|main|exit||_T_ABS_|||code:1
 		d0|main|atexit||_T_ABS_|||code:1
@@ -82,7 +82,7 @@ test_expect_success 'perf stream, error event' '
 	perl "$TEST_DIRECTORY/t0211/scrub_perf.perl" <trace.perf >actual &&
 	cat >expect <<-EOF &&
 		d0|main|version|||||$V
-		d0|main|start|||||_EXE_ trace2 003error '\''hello world'\'' '\''this is a test'\''
+		d0|main|start||_T_ABS_|||_EXE_ trace2 003error '\''hello world'\'' '\''this is a test'\''
 		d0|main|cmd_name|||||trace2 (trace2)
 		d0|main|error|||||hello world
 		d0|main|error|||||this is a test
@@ -128,15 +128,15 @@ test_expect_success 'perf stream, child processes' '
 	perl "$TEST_DIRECTORY/t0211/scrub_perf.perl" <trace.perf >actual &&
 	cat >expect <<-EOF &&
 		d0|main|version|||||$V
-		d0|main|start|||||_EXE_ trace2 004child test-tool trace2 004child test-tool trace2 001return 0
+		d0|main|start||_T_ABS_|||_EXE_ trace2 004child test-tool trace2 004child test-tool trace2 001return 0
 		d0|main|cmd_name|||||trace2 (trace2)
 		d0|main|child_start||_T_ABS_|||[ch0] class:? argv: test-tool trace2 004child test-tool trace2 001return 0
 		d1|main|version|||||$V
-		d1|main|start|||||_EXE_ trace2 004child test-tool trace2 001return 0
+		d1|main|start||_T_ABS_|||_EXE_ trace2 004child test-tool trace2 001return 0
 		d1|main|cmd_name|||||trace2 (trace2/trace2)
 		d1|main|child_start||_T_ABS_|||[ch0] class:? argv: test-tool trace2 001return 0
 		d2|main|version|||||$V
-		d2|main|start|||||_EXE_ trace2 001return 0
+		d2|main|start||_T_ABS_|||_EXE_ trace2 001return 0
 		d2|main|cmd_name|||||trace2 (trace2/trace2/trace2)
 		d2|main|exit||_T_ABS_|||code:0
 		d2|main|atexit||_T_ABS_|||code:0
diff --git a/trace2.c b/trace2.c
index 6dd51e6aa5..1c180062dd 100644
--- a/trace2.c
+++ b/trace2.c
@@ -182,13 +182,19 @@ void trace2_cmd_start_fl(const char *file, int line, const char **argv)
 {
 	struct tr2_tgt *tgt_j;
 	int j;
+	uint64_t us_now;
+	uint64_t us_elapsed_absolute;
 
 	if (!trace2_enabled)
 		return;
 
+	us_now = getnanotime() / 1000;
+	us_elapsed_absolute = tr2tls_absolute_elapsed(us_now);
+
 	for_each_wanted_builtin (j, tgt_j)
 		if (tgt_j->pfn_start_fl)
-			tgt_j->pfn_start_fl(file, line, argv);
+			tgt_j->pfn_start_fl(file, line, us_elapsed_absolute,
+					    argv);
 }
 
 int trace2_cmd_exit_fl(const char *file, int line, int code)
diff --git a/trace2/tr2_tgt.h b/trace2/tr2_tgt.h
index 297bb8ffbe..7b90469212 100644
--- a/trace2/tr2_tgt.h
+++ b/trace2/tr2_tgt.h
@@ -15,6 +15,7 @@ typedef void(tr2_tgt_term_t)(void);
 typedef void(tr2_tgt_evt_version_fl_t)(const char *file, int line);
 
 typedef void(tr2_tgt_evt_start_fl_t)(const char *file, int line,
+				     uint64_t us_elapsed_absolute,
 				     const char **argv);
 typedef void(tr2_tgt_evt_exit_fl_t)(const char *file, int line,
 				    uint64_t us_elapsed_absolute, int code);
diff --git a/trace2/tr2_tgt_event.c b/trace2/tr2_tgt_event.c
index 107cb5317d..89a4d3ae9a 100644
--- a/trace2/tr2_tgt_event.c
+++ b/trace2/tr2_tgt_event.c
@@ -122,13 +122,16 @@ static void fn_version_fl(const char *file, int line)
 	jw_release(&jw);
 }
 
-static void fn_start_fl(const char *file, int line, const char **argv)
+static void fn_start_fl(const char *file, int line,
+			uint64_t us_elapsed_absolute, const char **argv)
 {
 	const char *event_name = "start";
 	struct json_writer jw = JSON_WRITER_INIT;
+	double t_abs = (double)us_elapsed_absolute / 1000000.0;
 
 	jw_object_begin(&jw, 0);
 	event_fmt_prepare(event_name, file, line, NULL, &jw);
+	jw_object_double(&jw, "t_abs", 6, t_abs);
 	jw_object_inline_begin_array(&jw, "argv");
 	jw_array_argv(&jw, argv);
 	jw_end(&jw);
diff --git a/trace2/tr2_tgt_normal.c b/trace2/tr2_tgt_normal.c
index 547183d5b6..57f3e18f5b 100644
--- a/trace2/tr2_tgt_normal.c
+++ b/trace2/tr2_tgt_normal.c
@@ -81,7 +81,8 @@ static void fn_version_fl(const char *file, int line)
 	strbuf_release(&buf_payload);
 }
 
-static void fn_start_fl(const char *file, int line, const char **argv)
+static void fn_start_fl(const char *file, int line,
+			uint64_t us_elapsed_absolute, const char **argv)
 {
 	struct strbuf buf_payload = STRBUF_INIT;
 
diff --git a/trace2/tr2_tgt_perf.c b/trace2/tr2_tgt_perf.c
index f0746fcf86..9c3b4d8a0f 100644
--- a/trace2/tr2_tgt_perf.c
+++ b/trace2/tr2_tgt_perf.c
@@ -159,15 +159,16 @@ static void fn_version_fl(const char *file, int line)
 	strbuf_release(&buf_payload);
 }
 
-static void fn_start_fl(const char *file, int line, const char **argv)
+static void fn_start_fl(const char *file, int line,
+			uint64_t us_elapsed_absolute, const char **argv)
 {
 	const char *event_name = "start";
 	struct strbuf buf_payload = STRBUF_INIT;
 
 	sq_quote_argv_pretty(&buf_payload, argv);
 
-	perf_io_write_fl(file, line, event_name, NULL, NULL, NULL, NULL,
-			 &buf_payload);
+	perf_io_write_fl(file, line, event_name, NULL, &us_elapsed_absolute,
+			 NULL, NULL, &buf_payload);
 	strbuf_release(&buf_payload);
 }
 
-- 
gitgitgadget


^ permalink raw reply	[flat|nested] 68+ messages in thread

* [PATCH 3/4] trace2: find exec-dir before trace2 initialization
  2019-03-28 13:30 [PATCH 0/4] trace2: load trace2 settings from system config Jeff Hostetler via GitGitGadget
  2019-03-28 13:30 ` [PATCH 1/4] trace2: refactor setting process starting time Jeff Hostetler via GitGitGadget
  2019-03-28 13:31 ` [PATCH 2/4] trace2: add absolute elapsed time to start event Jeff Hostetler via GitGitGadget
@ 2019-03-28 13:31 ` Jeff Hostetler via GitGitGadget
  2019-03-28 13:31 ` [PATCH 4/4] trace2: use system config for default trace2 settings Jeff Hostetler via GitGitGadget
  2019-03-29 17:04 ` [PATCH v2 0/7] trace2: load trace2 settings from system config Jeff Hostetler via GitGitGadget
  4 siblings, 0 replies; 68+ messages in thread
From: Jeff Hostetler via GitGitGadget @ 2019-03-28 13:31 UTC (permalink / raw)
  To: git
  Cc: gitster, peff, jrnieder, steadmon, avarab, Junio C Hamano,
	Jeff Hostetler

From: Jeff Hostetler <jeffhost@microsoft.com>

Teach Git to resolve the executable directory before initializing
Trace2.  This allows the system configuration directory to be
discovered earlier (because it is sometimes relative to the prefix
or runtime-prefix).

This will be used by the next commit to allow trace2 settings to
be loaded from the system config.

Signed-off-by: Jeff Hostetler <jeffhost@microsoft.com>
---
 common-main.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/common-main.c b/common-main.c
index 6137af0e63..299ca62a72 100644
--- a/common-main.c
+++ b/common-main.c
@@ -37,12 +37,12 @@ int main(int argc, const char **argv)
 	sanitize_stdfds();
 	restore_sigpipe_to_default();
 
+	git_resolve_executable_dir(argv[0]);
+
 	trace2_initialize();
 	trace2_cmd_start(argv);
 	trace2_collect_process_info();
 
-	git_resolve_executable_dir(argv[0]);
-
 	git_setup_gettext();
 
 	initialize_the_repository();
-- 
gitgitgadget


^ permalink raw reply	[flat|nested] 68+ messages in thread

* [PATCH 4/4] trace2: use system config for default trace2 settings
  2019-03-28 13:30 [PATCH 0/4] trace2: load trace2 settings from system config Jeff Hostetler via GitGitGadget
                   ` (2 preceding siblings ...)
  2019-03-28 13:31 ` [PATCH 3/4] trace2: find exec-dir before trace2 initialization Jeff Hostetler via GitGitGadget
@ 2019-03-28 13:31 ` Jeff Hostetler via GitGitGadget
  2019-03-28 14:36   ` Ævar Arnfjörð Bjarmason
  2019-03-28 21:28   ` Josh Steadmon
  2019-03-29 17:04 ` [PATCH v2 0/7] trace2: load trace2 settings from system config Jeff Hostetler via GitGitGadget
  4 siblings, 2 replies; 68+ messages in thread
From: Jeff Hostetler via GitGitGadget @ 2019-03-28 13:31 UTC (permalink / raw)
  To: git
  Cc: gitster, peff, jrnieder, steadmon, avarab, Junio C Hamano,
	Jeff Hostetler

From: Jeff Hostetler <jeffhost@microsoft.com>

Teach git to read the system config (usually "/etc/gitconfig") for
default Trace2 settings.  This allows system-wide Trace2 settings to
be installed and inherited to make it easier to manage a collection of
systems.

The original GIT_TR2* environment variables are loaded afterwards and
can be used to override the system settings.

Only the system config file is used.  Trace2 config values are ignored
in local, global, and other config files.  Likewise, the "-c" command
line arguments are ignored for Trace2 values.  These limits are for
performance reasons.

(1) For users not using Trace2, there should be minimal overhead to
detect that Trace2 is not enabled.  In particular, Trace2 should not
allocate lots of otherwise unused data strucutres.

(2) For accurate performance measurements, Trace2 should be initialized
as early in the git process as possible, and before most of the normal
git process initialization (which involves discovering the .git directory
and reading a hierarchy of config files).

Added the GIT_TEST_TR2_SYSTEM_CONFIG environment variable for testing
purposes to specify the pathname of a fake "system" config or disable
use of the system config.

Signed-off-by: Jeff Hostetler <jeffhost@microsoft.com>
---
 Documentation/technical/api-trace2.txt |  31 ++++++
 Makefile                               |   1 +
 t/t0210-trace2-normal.sh               |  41 +++++++-
 t/t0211-trace2-perf.sh                 |  41 +++++++-
 t/t0212-trace2-event.sh                |  52 +++++++++-
 trace2.c                               |   4 +
 trace2.h                               |   7 +-
 trace2/tr2_cfg.c                       |   7 +-
 trace2/tr2_dst.c                       |  24 ++---
 trace2/tr2_dst.h                       |   3 +-
 trace2/tr2_sysenv.c                    | 125 +++++++++++++++++++++++++
 trace2/tr2_sysenv.h                    |  36 +++++++
 trace2/tr2_tgt_event.c                 |  19 ++--
 trace2/tr2_tgt_normal.c                |  10 +-
 trace2/tr2_tgt_perf.c                  |  10 +-
 15 files changed, 356 insertions(+), 55 deletions(-)
 create mode 100644 trace2/tr2_sysenv.c
 create mode 100644 trace2/tr2_sysenv.h

diff --git a/Documentation/technical/api-trace2.txt b/Documentation/technical/api-trace2.txt
index baaa1153bb..13ca595c69 100644
--- a/Documentation/technical/api-trace2.txt
+++ b/Documentation/technical/api-trace2.txt
@@ -117,6 +117,37 @@ values are recognized.
 Socket type can be either `stream` or `dgram`.  If the socket type is
 omitted, Git will try both.
 
+== Trace2 Settings in System Config
+
+Trace2 also reads configuration information from the system config.
+This is intended to help adminstrators to gather system-wide Git
+performance data.
+
+Trace2 only reads the system configuration, it does not read global,
+local, worktree, or `-c` config settings.
+
+Trace2 will try to load the following system configuration settings
+and then read the corresponding environment variables at startup.
+
+....
+---------------------------------------------------
+trace2.normalTarget          GIT_TR2
+trace2.normalBrief           GIT_TR2_BRIEF
+
+trace2.perfTarget            GIT_TR2_PERF
+trace2.perfBrief             GIT_TR2_PERF_BRIEF
+
+trace2.eventTarget           GIT_TR2_EVENT
+trace2.eventBrief            GIT_TR2_EVENT_BRIEF
+trace2.eventNesting          GIT_TR2_EVENT_NESTING
+
+trace2.configParams          GIT_TR2_CONFIG_PARAMS
+
+trace2.destinationDebug      GIT_TR2_DST_DEBUG
+---------------------------------------------------
+....
+
+
 == Trace2 API
 
 All public Trace2 functions and macros are defined in `trace2.h` and
diff --git a/Makefile b/Makefile
index 3e03290d8f..9ddfa3dfe7 100644
--- a/Makefile
+++ b/Makefile
@@ -1005,6 +1005,7 @@ LIB_OBJS += trace2/tr2_cfg.o
 LIB_OBJS += trace2/tr2_cmd_name.o
 LIB_OBJS += trace2/tr2_dst.o
 LIB_OBJS += trace2/tr2_sid.o
+LIB_OBJS += trace2/tr2_sysenv.o
 LIB_OBJS += trace2/tr2_tbuf.o
 LIB_OBJS += trace2/tr2_tgt_event.o
 LIB_OBJS += trace2/tr2_tgt_normal.o
diff --git a/t/t0210-trace2-normal.sh b/t/t0210-trace2-normal.sh
index 03a0aedb1d..5d4c04ed30 100755
--- a/t/t0210-trace2-normal.sh
+++ b/t/t0210-trace2-normal.sh
@@ -1,5 +1,14 @@
 #!/bin/sh
 
+# Disable loading of Trace2 settings from the system config
+# (usually "/etc/gitconfig") to eliminate system dependencies.
+GIT_TEST_TR2_SYSTEM_CONFIG=0 && export GIT_TEST_TR2_SYSTEM_CONFIG
+
+# Turn off any inherited trace2 settings for this test.
+unset GIT_TR2 GIT_TR2_PERF GIT_TR2_EVENT
+unset GIT_TR2_BRIEF
+unset GIT_TR2_CONFIG_PARAMS
+
 test_description='test trace2 facility (normal target)'
 . ./test-lib.sh
 
@@ -15,11 +24,6 @@ PATH="$TTDIR:$PATH" && export PATH
 # Warning: So you may see extra lines in artifact files when
 # Warning: interactively debugging.
 
-# Turn off any inherited trace2 settings for this test.
-unset GIT_TR2 GIT_TR2_PERF GIT_TR2_EVENT
-unset GIT_TR2_BRIEF
-unset GIT_TR2_CONFIG_PARAMS
-
 V=$(git version | sed -e 's/^git version //') && export V
 
 # There are multiple trace2 targets: normal, perf, and event.
@@ -132,4 +136,31 @@ test_expect_success 'normal stream, error event' '
 	test_cmp expect actual
 '
 
+# Now test using system config by using a mocked up config file
+# rather than inheriting "/etc/gitconfig".  Here we do not use
+# GIT_TR2* environment variables.
+
+unset GIT_TR2_BRIEF
+
+MOCK=./mock_system_config
+
+test_expect_success 'setup mocked /etc/gitconfig' '
+	git config --file $MOCK trace2.normalTarget "$(pwd)/trace.normal" &&
+	git config --file $MOCK trace2.normalBrief 1
+'
+
+test_expect_success 'using mock, normal stream, return code 0' '
+	test_when_finished "rm trace.normal actual expect" &&
+	GIT_TEST_TR2_SYSTEM_CONFIG="$MOCK" test-tool trace2 001return 0 &&
+	perl "$TEST_DIRECTORY/t0210/scrub_normal.perl" <trace.normal >actual &&
+	cat >expect <<-EOF &&
+		version $V
+		start _EXE_ trace2 001return 0
+		cmd_name trace2 (trace2)
+		exit elapsed:_TIME_ code:0
+		atexit elapsed:_TIME_ code:0
+	EOF
+	test_cmp expect actual
+'
+
 test_done
diff --git a/t/t0211-trace2-perf.sh b/t/t0211-trace2-perf.sh
index c9694b29f7..abe35b2186 100755
--- a/t/t0211-trace2-perf.sh
+++ b/t/t0211-trace2-perf.sh
@@ -1,5 +1,14 @@
 #!/bin/sh
 
+# Disable loading of Trace2 settings from the system config
+# (usually "/etc/gitconfig") to eliminate system dependencies.
+GIT_TEST_TR2_SYSTEM_CONFIG=0 && export GIT_TEST_TR2_SYSTEM_CONFIG
+
+# Turn off any inherited trace2 settings for this test.
+unset GIT_TR2 GIT_TR2_PERF GIT_TR2_EVENT
+unset GIT_TR2_PERF_BRIEF
+unset GIT_TR2_CONFIG_PARAMS
+
 test_description='test trace2 facility (perf target)'
 . ./test-lib.sh
 
@@ -15,11 +24,6 @@ PATH="$TTDIR:$PATH" && export PATH
 # Warning: So you may see extra lines in artifact files when
 # Warning: interactively debugging.
 
-# Turn off any inherited trace2 settings for this test.
-unset GIT_TR2 GIT_TR2_PERF GIT_TR2_EVENT
-unset GIT_TR2_PERF_BRIEF
-unset GIT_TR2_CONFIG_PARAMS
-
 V=$(git version | sed -e 's/^git version //') && export V
 
 # There are multiple trace2 targets: normal, perf, and event.
@@ -150,4 +154,31 @@ test_expect_success 'perf stream, child processes' '
 	test_cmp expect actual
 '
 
+# Now test using system config by using a mocked up config file
+# rather than inheriting "/etc/gitconfig".  Here we do not use
+# GIT_TR2* environment variables.
+
+unset GIT_TR2_PERF_BRIEF
+
+MOCK=./mock_system_config
+
+test_expect_success 'setup mocked /etc/gitconfig' '
+	git config --file $MOCK trace2.perfTarget "$(pwd)/trace.perf" &&
+	git config --file $MOCK trace2.perfBrief 1
+'
+
+test_expect_success 'using mock, perf stream, return code 0' '
+	test_when_finished "rm trace.perf actual expect" &&
+	GIT_TEST_TR2_SYSTEM_CONFIG="$MOCK" test-tool trace2 001return 0 &&
+	perl "$TEST_DIRECTORY/t0211/scrub_perf.perl" <trace.perf >actual &&
+	cat >expect <<-EOF &&
+		d0|main|version|||||$V
+		d0|main|start||_T_ABS_|||_EXE_ trace2 001return 0
+		d0|main|cmd_name|||||trace2 (trace2)
+		d0|main|exit||_T_ABS_|||code:0
+		d0|main|atexit||_T_ABS_|||code:0
+	EOF
+	test_cmp expect actual
+'
+
 test_done
diff --git a/t/t0212-trace2-event.sh b/t/t0212-trace2-event.sh
index 028b6c5671..c535496261 100755
--- a/t/t0212-trace2-event.sh
+++ b/t/t0212-trace2-event.sh
@@ -1,5 +1,14 @@
 #!/bin/sh
 
+# Disable loading of Trace2 settings from the system config
+# (usually "/etc/gitconfig") to eliminate system dependencies.
+GIT_TEST_TR2_SYSTEM_CONFIG=0 && export GIT_TEST_TR2_SYSTEM_CONFIG
+
+# Turn off any inherited trace2 settings for this test.
+unset GIT_TR2 GIT_TR2_PERF GIT_TR2_EVENT
+unset GIT_TR2_BARE
+unset GIT_TR2_CONFIG_PARAMS
+
 test_description='test trace2 facility'
 . ./test-lib.sh
 
@@ -17,11 +26,6 @@ PATH="$TTDIR:$PATH" && export PATH
 # Warning: So you may see extra lines in artifact files when
 # Warning: interactively debugging.
 
-# Turn off any inherited trace2 settings for this test.
-unset GIT_TR2 GIT_TR2_PERF GIT_TR2_EVENT
-unset GIT_TR2_BARE
-unset GIT_TR2_CONFIG_PARAMS
-
 V=$(git version | sed -e 's/^git version //') && export V
 
 # There are multiple trace2 targets: normal, perf, and event.
@@ -233,4 +237,42 @@ test_expect_success JSON_PP 'basic trace2_data' '
 	test_cmp expect actual
 '
 
+# Now test using system config by using a mocked up config file
+# rather than inheriting "/etc/gitconfig".  Here we do not use
+# GIT_TR2* environment variables.
+
+MOCK=./mock_system_config
+
+test_expect_success 'setup mocked /etc/gitconfig' '
+	git config --file $MOCK trace2.eventTarget "$(pwd)/trace.event"
+'
+
+test_expect_success JSON_PP 'using mock, event stream, error event' '
+	test_when_finished "rm trace.event actual expect" &&
+	GIT_TEST_TR2_SYSTEM_CONFIG="$MOCK" test-tool trace2 003error "hello world" "this is a test" &&
+	perl "$TEST_DIRECTORY/t0212/parse_events.perl" <trace.event >actual &&
+	sed -e "s/^|//" >expect <<-EOF &&
+	|VAR1 = {
+	|  "_SID0_":{
+	|    "argv":[
+	|      "_EXE_",
+	|      "trace2",
+	|      "003error",
+	|      "hello world",
+	|      "this is a test"
+	|    ],
+	|    "errors":[
+	|      "%s",
+	|      "%s"
+	|    ],
+	|    "exit_code":0,
+	|    "hierarchy":"trace2",
+	|    "name":"trace2",
+	|    "version":"$V"
+	|  }
+	|};
+	EOF
+	test_cmp expect actual
+'
+
 test_done
diff --git a/trace2.c b/trace2.c
index 1c180062dd..490b3f071e 100644
--- a/trace2.c
+++ b/trace2.c
@@ -10,6 +10,7 @@
 #include "trace2/tr2_cmd_name.h"
 #include "trace2/tr2_dst.h"
 #include "trace2/tr2_sid.h"
+#include "trace2/tr2_sysenv.h"
 #include "trace2/tr2_tgt.h"
 #include "trace2/tr2_tls.h"
 
@@ -120,6 +121,7 @@ static void tr2main_atexit_handler(void)
 	tr2_sid_release();
 	tr2_cmd_name_release();
 	tr2_cfg_free_patterns();
+	tr2_sysenv_release();
 
 	trace2_enabled = 0;
 }
@@ -155,6 +157,8 @@ void trace2_initialize_fl(const char *file, int line)
 	if (trace2_enabled)
 		return;
 
+	tr2_sysenv_load();
+
 	if (!tr2_tgt_want_builtins())
 		return;
 	trace2_enabled = 1;
diff --git a/trace2.h b/trace2.h
index 8f89e70c44..cda8349058 100644
--- a/trace2.h
+++ b/trace2.h
@@ -38,7 +38,8 @@ void trace2_initialize_clock(void);
 
 /*
  * Initialize TRACE2 tracing facility if any of the builtin TRACE2
- * targets are enabled in the environment.  Emits a 'version' event.
+ * targets are enabled in the system config or the environment.
+ * Emits a 'version' event.
  *
  * Cleanup/Termination is handled automatically by a registered
  * atexit() routine.
@@ -125,8 +126,8 @@ void trace2_cmd_alias_fl(const char *file, int line, const char *alias,
  * Emit one or more 'def_param' events for "interesting" configuration
  * settings.
  *
- * The environment variable "GIT_TR2_CONFIG_PARAMS" can be set to a
- * list of patterns considered important.  For example:
+ * Use the TR2_SYSENV_CFG_PARAM setting to register a list of patterns
+ * configured important.  For example:
  *
  *    GIT_TR2_CONFIG_PARAMS="core.*,remote.*.url"
  *
diff --git a/trace2/tr2_cfg.c b/trace2/tr2_cfg.c
index b329921ac5..caa7f06948 100644
--- a/trace2/tr2_cfg.c
+++ b/trace2/tr2_cfg.c
@@ -1,8 +1,7 @@
 #include "cache.h"
 #include "config.h"
-#include "tr2_cfg.h"
-
-#define TR2_ENVVAR_CFG_PARAM "GIT_TR2_CONFIG_PARAMS"
+#include "trace2/tr2_cfg.h"
+#include "trace2/tr2_sysenv.h"
 
 static struct strbuf **tr2_cfg_patterns;
 static int tr2_cfg_count_patterns;
@@ -21,7 +20,7 @@ static int tr2_cfg_load_patterns(void)
 		return tr2_cfg_count_patterns;
 	tr2_cfg_loaded = 1;
 
-	envvar = getenv(TR2_ENVVAR_CFG_PARAM);
+	envvar = tr2_sysenv_get(TR2_SYSENV_CFG_PARAM);
 	if (!envvar || !*envvar)
 		return tr2_cfg_count_patterns;
 
diff --git a/trace2/tr2_dst.c b/trace2/tr2_dst.c
index fd490a43ad..575cd69aa9 100644
--- a/trace2/tr2_dst.c
+++ b/trace2/tr2_dst.c
@@ -1,5 +1,6 @@
 #include "cache.h"
 #include "trace2/tr2_dst.h"
+#include "trace2/tr2_sysenv.h"
 
 /*
  * If a Trace2 target cannot be opened for writing, we should issue a
@@ -7,17 +8,13 @@
  * or socket and beyond the user's control -- especially since every
  * git command (and sub-command) will print the message.  So we silently
  * eat these warnings and just discard the trace data.
- *
- * Enable the following environment variable to see these warnings.
  */
-#define TR2_ENVVAR_DST_DEBUG "GIT_TR2_DST_DEBUG"
-
 static int tr2_dst_want_warning(void)
 {
 	static int tr2env_dst_debug = -1;
 
 	if (tr2env_dst_debug == -1) {
-		const char *env_value = getenv(TR2_ENVVAR_DST_DEBUG);
+		const char *env_value = tr2_sysenv_get(TR2_SYSENV_DST_DEBUG);
 		if (!env_value || !*env_value)
 			tr2env_dst_debug = 0;
 		else
@@ -42,7 +39,9 @@ static int tr2_dst_try_path(struct tr2_dst *dst, const char *tgt_value)
 	if (fd == -1) {
 		if (tr2_dst_want_warning())
 			warning("trace2: could not open '%s' for '%s' tracing: %s",
-				tgt_value, dst->env_var_name, strerror(errno));
+				tgt_value,
+				tr2_sysenv_display_name(dst->sysenv_var),
+				strerror(errno));
 
 		tr2_dst_trace_disable(dst);
 		return 0;
@@ -116,7 +115,7 @@ static int tr2_dst_try_unix_domain_socket(struct tr2_dst *dst,
 	if (!path || !*path) {
 		if (tr2_dst_want_warning())
 			warning("trace2: invalid AF_UNIX value '%s' for '%s' tracing",
-				tgt_value, dst->env_var_name);
+				tgt_value, tr2_sysenv_display_name(dst->sysenv_var));
 
 		tr2_dst_trace_disable(dst);
 		return 0;
@@ -126,7 +125,7 @@ static int tr2_dst_try_unix_domain_socket(struct tr2_dst *dst,
 	    strlen(path) >= sizeof(((struct sockaddr_un *)0)->sun_path)) {
 		if (tr2_dst_want_warning())
 			warning("trace2: invalid AF_UNIX path '%s' for '%s' tracing",
-				path, dst->env_var_name);
+				path, tr2_sysenv_display_name(dst->sysenv_var));
 
 		tr2_dst_trace_disable(dst);
 		return 0;
@@ -148,7 +147,7 @@ static int tr2_dst_try_unix_domain_socket(struct tr2_dst *dst,
 error:
 	if (tr2_dst_want_warning())
 		warning("trace2: could not connect to socket '%s' for '%s' tracing: %s",
-			path, dst->env_var_name, strerror(e));
+			path, tr2_sysenv_display_name(dst->sysenv_var), strerror(e));
 
 	tr2_dst_trace_disable(dst);
 	return 0;
@@ -168,7 +167,7 @@ static void tr2_dst_malformed_warning(struct tr2_dst *dst,
 	struct strbuf buf = STRBUF_INIT;
 
 	strbuf_addf(&buf, "trace2: unknown value for '%s': '%s'",
-		    dst->env_var_name, tgt_value);
+		    tr2_sysenv_display_name(dst->sysenv_var), tgt_value);
 	warning("%s", buf.buf);
 
 	strbuf_release(&buf);
@@ -184,7 +183,7 @@ int tr2_dst_get_trace_fd(struct tr2_dst *dst)
 
 	dst->initialized = 1;
 
-	tgt_value = getenv(dst->env_var_name);
+	tgt_value = tr2_sysenv_get(dst->sysenv_var);
 
 	if (!tgt_value || !strcmp(tgt_value, "") || !strcmp(tgt_value, "0") ||
 	    !strcasecmp(tgt_value, "false")) {
@@ -246,7 +245,8 @@ void tr2_dst_write_line(struct tr2_dst *dst, struct strbuf *buf_line)
 		return;
 
 	if (tr2_dst_want_warning())
-		warning("unable to write trace to '%s': %s", dst->env_var_name,
+		warning("unable to write trace to '%s': %s",
+			tr2_sysenv_display_name(dst->sysenv_var),
 			strerror(errno));
 	tr2_dst_trace_disable(dst);
 }
diff --git a/trace2/tr2_dst.h b/trace2/tr2_dst.h
index 9a64f05b02..3adf3bac13 100644
--- a/trace2/tr2_dst.h
+++ b/trace2/tr2_dst.h
@@ -2,9 +2,10 @@
 #define TR2_DST_H
 
 struct strbuf;
+#include "trace2/tr2_sysenv.h"
 
 struct tr2_dst {
-	const char *const env_var_name;
+	enum tr2_sysenv_variable sysenv_var;
 	int fd;
 	unsigned int initialized : 1;
 	unsigned int need_close : 1;
diff --git a/trace2/tr2_sysenv.c b/trace2/tr2_sysenv.c
new file mode 100644
index 0000000000..656613e371
--- /dev/null
+++ b/trace2/tr2_sysenv.c
@@ -0,0 +1,125 @@
+#include "cache.h"
+#include "config.h"
+#include "dir.h"
+#include "tr2_sysenv.h"
+
+/*
+ * Each entry represents a trace2 setting.
+ * See Documentation/technical/api-trace2.txt
+ */
+struct tr2_sysenv_entry {
+	const char *env_var_name;
+	const char *git_config_name;
+
+	char *value;
+	unsigned int getenv_called : 1;
+};
+
+/*
+ * This table must match "enum tr2_sysenv_variable" in tr2_sysenv.h.
+ * These strings are constant and must match the published names as
+ * described in the documentation.
+ *
+ * We do not define entries for the GIT_TR2_PARENT_* environment
+ * variables because they are transient and used to pass information
+ * from parent to child git processes, rather than settings.
+ */
+/* clang-format off */
+static struct tr2_sysenv_entry tr2_sysenv_settings[] = {
+	{ "GIT_TR2_CONFIG_PARAMS",   "trace2.configparams"     },
+
+	{ "GIT_TR2_DST_DEBUG",       "trace2.destinationdebug" },
+
+	{ "GIT_TR2",                 "trace2.normaltarget"     },
+	{ "GIT_TR2_BRIEF",           "trace2.normalbrief"      },
+
+	{ "GIT_TR2_EVENT",           "trace2.eventtarget"      },
+	{ "GIT_TR2_EVENT_BRIEF",     "trace2.eventbrief"       },
+	{ "GIT_TR2_EVENT_NESTING",   "trace2.eventnesting"     },
+
+	{ "GIT_TR2_PERF",            "trace2.perftarget"       },
+	{ "GIT_TR2_PERF_BRIEF",      "trace2.perfbrief"        },
+};
+/* clang-format on */
+
+static int tr2_sysenv_cb(const char *key, const char *value, void *d)
+{
+	int k;
+
+	for (k = 0; k < ARRAY_SIZE(tr2_sysenv_settings); k++) {
+		if (!strcmp(key, tr2_sysenv_settings[k].git_config_name)) {
+			free(tr2_sysenv_settings[k].value);
+			tr2_sysenv_settings[k].value = xstrdup(value);
+			return 0;
+		}
+	}
+
+	return 0;
+}
+
+/*
+ * Load Trace2 settings from the system config (usually "/etc/gitconfig"
+ * unless we were built with a runtime-prefix).  These are intended to
+ * define the default values for Trace2 as requested by the administrator.
+ */
+void tr2_sysenv_load(void)
+{
+	const char *system_config_pathname;
+	const char *test_pathname;
+
+	system_config_pathname = git_etc_gitconfig();
+
+	test_pathname = getenv("GIT_TEST_TR2_SYSTEM_CONFIG");
+	if (test_pathname) {
+		if (!*test_pathname || !strcmp(test_pathname, "0"))
+			return; /* disable use of system config */
+
+		/* mock it with given test file */
+		system_config_pathname = test_pathname;
+	}
+
+	if (file_exists(system_config_pathname))
+		git_config_from_file(tr2_sysenv_cb, system_config_pathname,
+				     NULL);
+}
+
+/*
+ * Return the value for the requested setting.  Start with the /etc/gitconfig
+ * value and allow the corresponding environment variable to override it.
+ */
+const char *tr2_sysenv_get(enum tr2_sysenv_variable var)
+{
+	if (var >= TR2_SYSENV_MUST_BE_LAST)
+		BUG("tr2_sysenv_get invalid var '%d'", var);
+
+	if (!tr2_sysenv_settings[var].getenv_called) {
+		const char *v = getenv(tr2_sysenv_settings[var].env_var_name);
+		if (v && *v) {
+			free(tr2_sysenv_settings[var].value);
+			tr2_sysenv_settings[var].value = xstrdup(v);
+		}
+		tr2_sysenv_settings[var].getenv_called = 1;
+	}
+
+	return tr2_sysenv_settings[var].value;
+}
+
+/*
+ * Return a friendly name for this setting that is suitable for printing
+ * in an error messages.
+ */
+const char *tr2_sysenv_display_name(enum tr2_sysenv_variable var)
+{
+	if (var >= TR2_SYSENV_MUST_BE_LAST)
+		BUG("tr2_sysenv_get invalid var '%d'", var);
+
+	return tr2_sysenv_settings[var].env_var_name;
+}
+
+void tr2_sysenv_release(void)
+{
+	int k;
+
+	for (k = 0; k < ARRAY_SIZE(tr2_sysenv_settings); k++)
+		free(tr2_sysenv_settings[k].value);
+}
diff --git a/trace2/tr2_sysenv.h b/trace2/tr2_sysenv.h
new file mode 100644
index 0000000000..369b20bd87
--- /dev/null
+++ b/trace2/tr2_sysenv.h
@@ -0,0 +1,36 @@
+#ifndef TR2_SYSENV_H
+#define TR2_SYSENV_H
+
+/*
+ * The Trace2 settings that can be loaded from /etc/gitconfig
+ * and/or user environment variables.
+ *
+ * Note that this set does not contain any of the transient
+ * environment variables used to pass information from parent
+ * to child git processes, such "GIT_TR2_PARENT_SID".
+ */
+enum tr2_sysenv_variable {
+	TR2_SYSENV_CFG_PARAM = 0,
+
+	TR2_SYSENV_DST_DEBUG,
+
+	TR2_SYSENV_NORMAL,
+	TR2_SYSENV_NORMAL_BRIEF,
+
+	TR2_SYSENV_EVENT,
+	TR2_SYSENV_EVENT_BRIEF,
+	TR2_SYSENV_EVENT_NESTING,
+
+	TR2_SYSENV_PERF,
+	TR2_SYSENV_PERF_BRIEF,
+
+	TR2_SYSENV_MUST_BE_LAST
+};
+
+void tr2_sysenv_load(void);
+
+const char *tr2_sysenv_get(enum tr2_sysenv_variable);
+const char *tr2_sysenv_display_name(enum tr2_sysenv_variable var);
+void tr2_sysenv_release(void);
+
+#endif /* TR2_SYSENV_H */
diff --git a/trace2/tr2_tgt_event.c b/trace2/tr2_tgt_event.c
index 89a4d3ae9a..bb6e323953 100644
--- a/trace2/tr2_tgt_event.c
+++ b/trace2/tr2_tgt_event.c
@@ -6,10 +6,11 @@
 #include "trace2/tr2_dst.h"
 #include "trace2/tr2_tbuf.h"
 #include "trace2/tr2_sid.h"
+#include "trace2/tr2_sysenv.h"
 #include "trace2/tr2_tgt.h"
 #include "trace2/tr2_tls.h"
 
-static struct tr2_dst tr2dst_event = { "GIT_TR2_EVENT", 0, 0, 0 };
+static struct tr2_dst tr2dst_event = { TR2_SYSENV_EVENT, 0, 0, 0 };
 
 /*
  * The version number of the JSON data generated by the EVENT target
@@ -28,17 +29,15 @@ static struct tr2_dst tr2dst_event = { "GIT_TR2_EVENT", 0, 0, 0 };
  * are primarily intended for the performance target during debugging.
  *
  * Some of the outer-most messages, however, may be of interest to the
- * event target.  Set this environment variable to a larger integer for
- * more detail in the event target.
+ * event target.  Use the TR2_SYSENV_EVENT_NESTING setting to increase
+ * region details in the event target.
  */
-#define TR2_ENVVAR_EVENT_NESTING "GIT_TR2_EVENT_NESTING"
 static int tr2env_event_nesting_wanted = 2;
 
 /*
- * Set this environment variable to true to omit the <time>, <file>, and
+ * Use the TR2_SYSENV_EVENT_BRIEF to omit the <time>, <file>, and
  * <line> fields from most events.
  */
-#define TR2_ENVVAR_EVENT_BRIEF "GIT_TR2_EVENT_BRIEF"
 static int tr2env_event_brief;
 
 static int fn_init(void)
@@ -46,17 +45,17 @@ static int fn_init(void)
 	int want = tr2_dst_trace_want(&tr2dst_event);
 	int want_nesting;
 	int want_brief;
-	char *nesting;
-	char *brief;
+	const char *nesting;
+	const char *brief;
 
 	if (!want)
 		return want;
 
-	nesting = getenv(TR2_ENVVAR_EVENT_NESTING);
+	nesting = tr2_sysenv_get(TR2_SYSENV_EVENT_NESTING);
 	if (nesting && ((want_nesting = atoi(nesting)) > 0))
 		tr2env_event_nesting_wanted = want_nesting;
 
-	brief = getenv(TR2_ENVVAR_EVENT_BRIEF);
+	brief = tr2_sysenv_get(TR2_SYSENV_EVENT_BRIEF);
 	if (brief && ((want_brief = atoi(brief)) > 0))
 		tr2env_event_brief = want_brief;
 
diff --git a/trace2/tr2_tgt_normal.c b/trace2/tr2_tgt_normal.c
index 57f3e18f5b..3364223805 100644
--- a/trace2/tr2_tgt_normal.c
+++ b/trace2/tr2_tgt_normal.c
@@ -4,19 +4,19 @@
 #include "quote.h"
 #include "version.h"
 #include "trace2/tr2_dst.h"
+#include "trace2/tr2_sysenv.h"
 #include "trace2/tr2_tbuf.h"
 #include "trace2/tr2_tgt.h"
 #include "trace2/tr2_tls.h"
 
-static struct tr2_dst tr2dst_normal = { "GIT_TR2", 0, 0, 0 };
+static struct tr2_dst tr2dst_normal = { TR2_SYSENV_NORMAL, 0, 0, 0 };
 
 /*
- * Set this environment variable to true to omit the "<time> <file>:<line>"
+ * Use the TR2_SYSENV_NORMAL_BRIEF setting to omit the "<time> <file>:<line>"
  * fields from each line written to the builtin normal target.
  *
  * Unit tests may want to use this to help with testing.
  */
-#define TR2_ENVVAR_NORMAL_BRIEF "GIT_TR2_BRIEF"
 static int tr2env_normal_brief;
 
 #define TR2FMT_NORMAL_FL_WIDTH (50)
@@ -25,12 +25,12 @@ static int fn_init(void)
 {
 	int want = tr2_dst_trace_want(&tr2dst_normal);
 	int want_brief;
-	char *brief;
+	const char *brief;
 
 	if (!want)
 		return want;
 
-	brief = getenv(TR2_ENVVAR_NORMAL_BRIEF);
+	brief = tr2_sysenv_get(TR2_SYSENV_NORMAL_BRIEF);
 	if (brief && *brief &&
 	    ((want_brief = git_parse_maybe_bool(brief)) != -1))
 		tr2env_normal_brief = want_brief;
diff --git a/trace2/tr2_tgt_perf.c b/trace2/tr2_tgt_perf.c
index 9c3b4d8a0f..1ad781c32e 100644
--- a/trace2/tr2_tgt_perf.c
+++ b/trace2/tr2_tgt_perf.c
@@ -6,19 +6,19 @@
 #include "json-writer.h"
 #include "trace2/tr2_dst.h"
 #include "trace2/tr2_sid.h"
+#include "trace2/tr2_sysenv.h"
 #include "trace2/tr2_tbuf.h"
 #include "trace2/tr2_tgt.h"
 #include "trace2/tr2_tls.h"
 
-static struct tr2_dst tr2dst_perf = { "GIT_TR2_PERF", 0, 0, 0 };
+static struct tr2_dst tr2dst_perf = { TR2_SYSENV_PERF, 0, 0, 0 };
 
 /*
- * Set this environment variable to true to omit the "<time> <file>:<line>"
+ * Use TR2_SYSENV_PERF_BRIEF to omit the "<time> <file>:<line>"
  * fields from each line written to the builtin performance target.
  *
  * Unit tests may want to use this to help with testing.
  */
-#define TR2_ENVVAR_PERF_BRIEF "GIT_TR2_PERF_BRIEF"
 static int tr2env_perf_brief;
 
 #define TR2FMT_PERF_FL_WIDTH (50)
@@ -36,14 +36,14 @@ static int fn_init(void)
 {
 	int want = tr2_dst_trace_want(&tr2dst_perf);
 	int want_brief;
-	char *brief;
+	const char *brief;
 
 	if (!want)
 		return want;
 
 	strbuf_addchars(&dots, '.', TR2_DOTS_BUFFER_SIZE);
 
-	brief = getenv(TR2_ENVVAR_PERF_BRIEF);
+	brief = tr2_sysenv_get(TR2_SYSENV_PERF_BRIEF);
 	if (brief && *brief &&
 	    ((want_brief = git_parse_maybe_bool(brief)) != -1))
 		tr2env_perf_brief = want_brief;
-- 
gitgitgadget

^ permalink raw reply	[flat|nested] 68+ messages in thread

* Re: [PATCH 4/4] trace2: use system config for default trace2 settings
  2019-03-28 13:31 ` [PATCH 4/4] trace2: use system config for default trace2 settings Jeff Hostetler via GitGitGadget
@ 2019-03-28 14:36   ` Ævar Arnfjörð Bjarmason
  2019-03-28 18:50     ` Jeff Hostetler
  2019-03-28 21:28   ` Josh Steadmon
  1 sibling, 1 reply; 68+ messages in thread
From: Ævar Arnfjörð Bjarmason @ 2019-03-28 14:36 UTC (permalink / raw)
  To: Jeff Hostetler via GitGitGadget
  Cc: git, peff, jrnieder, steadmon, Junio C Hamano, Jeff Hostetler


On Thu, Mar 28 2019, Jeff Hostetler via GitGitGadget wrote:

Thanks for working on this!

Haven't given this any deep testing. Just some observations:

> From: Jeff Hostetler <jeffhost@microsoft.com>
>
> Teach git to read the system config (usually "/etc/gitconfig") for
> default Trace2 settings.  This allows system-wide Trace2 settings to
> be installed and inherited to make it easier to manage a collection of
> systems.
>
> The original GIT_TR2* environment variables are loaded afterwards and
> can be used to override the system settings.
>
> Only the system config file is used.  Trace2 config values are ignored
> in local, global, and other config files.  Likewise, the "-c" command
> line arguments are ignored for Trace2 values.  These limits are for
> performance reasons.
>
> (1) For users not using Trace2, there should be minimal overhead to
> detect that Trace2 is not enabled.  In particular, Trace2 should not
> allocate lots of otherwise unused data strucutres.
>
> (2) For accurate performance measurements, Trace2 should be initialized
> as early in the git process as possible, and before most of the normal
> git process initialization (which involves discovering the .git directory
> and reading a hierarchy of config files).
>
> Added the GIT_TEST_TR2_SYSTEM_CONFIG environment variable for testing
> purposes to specify the pathname of a fake "system" config or disable
> use of the system config.
>
> Signed-off-by: Jeff Hostetler <jeffhost@microsoft.com>
> ---
>  Documentation/technical/api-trace2.txt |  31 ++++++
>  Makefile                               |   1 +
>  t/t0210-trace2-normal.sh               |  41 +++++++-
>  t/t0211-trace2-perf.sh                 |  41 +++++++-
>  t/t0212-trace2-event.sh                |  52 +++++++++-
>  trace2.c                               |   4 +
>  trace2.h                               |   7 +-
>  trace2/tr2_cfg.c                       |   7 +-
>  trace2/tr2_dst.c                       |  24 ++---
>  trace2/tr2_dst.h                       |   3 +-
>  trace2/tr2_sysenv.c                    | 125 +++++++++++++++++++++++++
>  trace2/tr2_sysenv.h                    |  36 +++++++
>  trace2/tr2_tgt_event.c                 |  19 ++--
>  trace2/tr2_tgt_normal.c                |  10 +-
>  trace2/tr2_tgt_perf.c                  |  10 +-
>  15 files changed, 356 insertions(+), 55 deletions(-)
>  create mode 100644 trace2/tr2_sysenv.c
>  create mode 100644 trace2/tr2_sysenv.h
>
> diff --git a/Documentation/technical/api-trace2.txt b/Documentation/technical/api-trace2.txt
> index baaa1153bb..13ca595c69 100644
> --- a/Documentation/technical/api-trace2.txt
> +++ b/Documentation/technical/api-trace2.txt
> @@ -117,6 +117,37 @@ values are recognized.
>  Socket type can be either `stream` or `dgram`.  If the socket type is
>  omitted, Git will try both.
>
> +== Trace2 Settings in System Config
> +
> +Trace2 also reads configuration information from the system config.
> +This is intended to help adminstrators to gather system-wide Git
> +performance data.
> +
> +Trace2 only reads the system configuration, it does not read global,
> +local, worktree, or `-c` config settings.
> +
> +Trace2 will try to load the following system configuration settings
> +and then read the corresponding environment variables at startup.
> +
> +....
> +---------------------------------------------------
> +trace2.normalTarget          GIT_TR2
> +trace2.normalBrief           GIT_TR2_BRIEF
> +
> +trace2.perfTarget            GIT_TR2_PERF
> +trace2.perfBrief             GIT_TR2_PERF_BRIEF
> +
> +trace2.eventTarget           GIT_TR2_EVENT
> +trace2.eventBrief            GIT_TR2_EVENT_BRIEF
> +trace2.eventNesting          GIT_TR2_EVENT_NESTING
> +
> +trace2.configParams          GIT_TR2_CONFIG_PARAMS
> +
> +trace2.destinationDebug      GIT_TR2_DST_DEBUG
> +---------------------------------------------------
> +....
> +
> +
>  == Trace2 API
>
>  All public Trace2 functions and macros are defined in `trace2.h` and
> diff --git a/Makefile b/Makefile
> index 3e03290d8f..9ddfa3dfe7 100644
> --- a/Makefile
> +++ b/Makefile
> @@ -1005,6 +1005,7 @@ LIB_OBJS += trace2/tr2_cfg.o
>  LIB_OBJS += trace2/tr2_cmd_name.o
>  LIB_OBJS += trace2/tr2_dst.o
>  LIB_OBJS += trace2/tr2_sid.o
> +LIB_OBJS += trace2/tr2_sysenv.o
>  LIB_OBJS += trace2/tr2_tbuf.o
>  LIB_OBJS += trace2/tr2_tgt_event.o
>  LIB_OBJS += trace2/tr2_tgt_normal.o
> diff --git a/t/t0210-trace2-normal.sh b/t/t0210-trace2-normal.sh
> index 03a0aedb1d..5d4c04ed30 100755
> --- a/t/t0210-trace2-normal.sh
> +++ b/t/t0210-trace2-normal.sh
> @@ -1,5 +1,14 @@
>  #!/bin/sh
>
> +# Disable loading of Trace2 settings from the system config
> +# (usually "/etc/gitconfig") to eliminate system dependencies.
> +GIT_TEST_TR2_SYSTEM_CONFIG=0 && export GIT_TEST_TR2_SYSTEM_CONFIG
> +
> +# Turn off any inherited trace2 settings for this test.
> +unset GIT_TR2 GIT_TR2_PERF GIT_TR2_EVENT
> +unset GIT_TR2_BRIEF
> +unset GIT_TR2_CONFIG_PARAMS
> +
>  test_description='test trace2 facility (normal target)'
>  . ./test-lib.sh
>
> @@ -15,11 +24,6 @@ PATH="$TTDIR:$PATH" && export PATH
>  # Warning: So you may see extra lines in artifact files when
>  # Warning: interactively debugging.
>
> -# Turn off any inherited trace2 settings for this test.
> -unset GIT_TR2 GIT_TR2_PERF GIT_TR2_EVENT
> -unset GIT_TR2_BRIEF
> -unset GIT_TR2_CONFIG_PARAMS
> -
>  V=$(git version | sed -e 's/^git version //') && export V
>
>  # There are multiple trace2 targets: normal, perf, and event.
> @@ -132,4 +136,31 @@ test_expect_success 'normal stream, error event' '
>  	test_cmp expect actual
>  '
>
> +# Now test using system config by using a mocked up config file
> +# rather than inheriting "/etc/gitconfig".  Here we do not use
> +# GIT_TR2* environment variables.
> +
> +unset GIT_TR2_BRIEF
> +
> +MOCK=./mock_system_config
> +
> +test_expect_success 'setup mocked /etc/gitconfig' '
> +	git config --file $MOCK trace2.normalTarget "$(pwd)/trace.normal" &&
> +	git config --file $MOCK trace2.normalBrief 1
> +'
> +
> +test_expect_success 'using mock, normal stream, return code 0' '
> +	test_when_finished "rm trace.normal actual expect" &&
> +	GIT_TEST_TR2_SYSTEM_CONFIG="$MOCK" test-tool trace2 001return 0 &&
> +	perl "$TEST_DIRECTORY/t0210/scrub_normal.perl" <trace.normal >actual &&
> +	cat >expect <<-EOF &&
> +		version $V
> +		start _EXE_ trace2 001return 0
> +		cmd_name trace2 (trace2)
> +		exit elapsed:_TIME_ code:0
> +		atexit elapsed:_TIME_ code:0
> +	EOF
> +	test_cmp expect actual
> +'
> +
>  test_done
> diff --git a/t/t0211-trace2-perf.sh b/t/t0211-trace2-perf.sh
> index c9694b29f7..abe35b2186 100755
> --- a/t/t0211-trace2-perf.sh
> +++ b/t/t0211-trace2-perf.sh
> @@ -1,5 +1,14 @@
>  #!/bin/sh
>
> +# Disable loading of Trace2 settings from the system config
> +# (usually "/etc/gitconfig") to eliminate system dependencies.
> +GIT_TEST_TR2_SYSTEM_CONFIG=0 && export GIT_TEST_TR2_SYSTEM_CONFIG
> +
> +# Turn off any inherited trace2 settings for this test.
> +unset GIT_TR2 GIT_TR2_PERF GIT_TR2_EVENT
> +unset GIT_TR2_PERF_BRIEF
> +unset GIT_TR2_CONFIG_PARAMS
> +
>  test_description='test trace2 facility (perf target)'
>  . ./test-lib.sh
>
> @@ -15,11 +24,6 @@ PATH="$TTDIR:$PATH" && export PATH
>  # Warning: So you may see extra lines in artifact files when
>  # Warning: interactively debugging.
>
> -# Turn off any inherited trace2 settings for this test.
> -unset GIT_TR2 GIT_TR2_PERF GIT_TR2_EVENT
> -unset GIT_TR2_PERF_BRIEF
> -unset GIT_TR2_CONFIG_PARAMS
> -
>  V=$(git version | sed -e 's/^git version //') && export V
>
>  # There are multiple trace2 targets: normal, perf, and event.
> @@ -150,4 +154,31 @@ test_expect_success 'perf stream, child processes' '
>  	test_cmp expect actual
>  '
>
> +# Now test using system config by using a mocked up config file
> +# rather than inheriting "/etc/gitconfig".  Here we do not use
> +# GIT_TR2* environment variables.
> +
> +unset GIT_TR2_PERF_BRIEF
> +
> +MOCK=./mock_system_config
> +
> +test_expect_success 'setup mocked /etc/gitconfig' '
> +	git config --file $MOCK trace2.perfTarget "$(pwd)/trace.perf" &&
> +	git config --file $MOCK trace2.perfBrief 1
> +'
> +
> +test_expect_success 'using mock, perf stream, return code 0' '
> +	test_when_finished "rm trace.perf actual expect" &&
> +	GIT_TEST_TR2_SYSTEM_CONFIG="$MOCK" test-tool trace2 001return 0 &&
> +	perl "$TEST_DIRECTORY/t0211/scrub_perf.perl" <trace.perf >actual &&
> +	cat >expect <<-EOF &&
> +		d0|main|version|||||$V
> +		d0|main|start||_T_ABS_|||_EXE_ trace2 001return 0
> +		d0|main|cmd_name|||||trace2 (trace2)
> +		d0|main|exit||_T_ABS_|||code:0
> +		d0|main|atexit||_T_ABS_|||code:0
> +	EOF
> +	test_cmp expect actual
> +'
> +
>  test_done
> diff --git a/t/t0212-trace2-event.sh b/t/t0212-trace2-event.sh
> index 028b6c5671..c535496261 100755
> --- a/t/t0212-trace2-event.sh
> +++ b/t/t0212-trace2-event.sh
> @@ -1,5 +1,14 @@
>  #!/bin/sh
>
> +# Disable loading of Trace2 settings from the system config
> +# (usually "/etc/gitconfig") to eliminate system dependencies.
> +GIT_TEST_TR2_SYSTEM_CONFIG=0 && export GIT_TEST_TR2_SYSTEM_CONFIG
> +
> +# Turn off any inherited trace2 settings for this test.
> +unset GIT_TR2 GIT_TR2_PERF GIT_TR2_EVENT
> +unset GIT_TR2_BARE
> +unset GIT_TR2_CONFIG_PARAMS
> +
>  test_description='test trace2 facility'
>  . ./test-lib.sh
>
> @@ -17,11 +26,6 @@ PATH="$TTDIR:$PATH" && export PATH
>  # Warning: So you may see extra lines in artifact files when
>  # Warning: interactively debugging.
>
> -# Turn off any inherited trace2 settings for this test.
> -unset GIT_TR2 GIT_TR2_PERF GIT_TR2_EVENT
> -unset GIT_TR2_BARE
> -unset GIT_TR2_CONFIG_PARAMS
> -
>  V=$(git version | sed -e 's/^git version //') && export V
>
>  # There are multiple trace2 targets: normal, perf, and event.
> @@ -233,4 +237,42 @@ test_expect_success JSON_PP 'basic trace2_data' '
>  	test_cmp expect actual
>  '
>
> +# Now test using system config by using a mocked up config file
> +# rather than inheriting "/etc/gitconfig".  Here we do not use
> +# GIT_TR2* environment variables.
> +
> +MOCK=./mock_system_config
> +
> +test_expect_success 'setup mocked /etc/gitconfig' '
> +	git config --file $MOCK trace2.eventTarget "$(pwd)/trace.event"
> +'
> +
> +test_expect_success JSON_PP 'using mock, event stream, error event' '
> +	test_when_finished "rm trace.event actual expect" &&
> +	GIT_TEST_TR2_SYSTEM_CONFIG="$MOCK" test-tool trace2 003error "hello world" "this is a test" &&
> +	perl "$TEST_DIRECTORY/t0212/parse_events.perl" <trace.event >actual &&
> +	sed -e "s/^|//" >expect <<-EOF &&
> +	|VAR1 = {
> +	|  "_SID0_":{
> +	|    "argv":[
> +	|      "_EXE_",
> +	|      "trace2",
> +	|      "003error",
> +	|      "hello world",
> +	|      "this is a test"
> +	|    ],
> +	|    "errors":[
> +	|      "%s",
> +	|      "%s"
> +	|    ],
> +	|    "exit_code":0,
> +	|    "hierarchy":"trace2",
> +	|    "name":"trace2",
> +	|    "version":"$V"
> +	|  }
> +	|};
> +	EOF
> +	test_cmp expect actual
> +'
> +
>  test_done
> diff --git a/trace2.c b/trace2.c
> index 1c180062dd..490b3f071e 100644
> --- a/trace2.c
> +++ b/trace2.c
> @@ -10,6 +10,7 @@
>  #include "trace2/tr2_cmd_name.h"
>  #include "trace2/tr2_dst.h"
>  #include "trace2/tr2_sid.h"
> +#include "trace2/tr2_sysenv.h"
>  #include "trace2/tr2_tgt.h"
>  #include "trace2/tr2_tls.h"
>
> @@ -120,6 +121,7 @@ static void tr2main_atexit_handler(void)
>  	tr2_sid_release();
>  	tr2_cmd_name_release();
>  	tr2_cfg_free_patterns();
> +	tr2_sysenv_release();
>
>  	trace2_enabled = 0;
>  }
> @@ -155,6 +157,8 @@ void trace2_initialize_fl(const char *file, int line)
>  	if (trace2_enabled)
>  		return;
>
> +	tr2_sysenv_load();
> +
>  	if (!tr2_tgt_want_builtins())
>  		return;
>  	trace2_enabled = 1;
> diff --git a/trace2.h b/trace2.h
> index 8f89e70c44..cda8349058 100644
> --- a/trace2.h
> +++ b/trace2.h
> @@ -38,7 +38,8 @@ void trace2_initialize_clock(void);
>
>  /*
>   * Initialize TRACE2 tracing facility if any of the builtin TRACE2
> - * targets are enabled in the environment.  Emits a 'version' event.
> + * targets are enabled in the system config or the environment.
> + * Emits a 'version' event.
>   *
>   * Cleanup/Termination is handled automatically by a registered
>   * atexit() routine.
> @@ -125,8 +126,8 @@ void trace2_cmd_alias_fl(const char *file, int line, const char *alias,
>   * Emit one or more 'def_param' events for "interesting" configuration
>   * settings.
>   *
> - * The environment variable "GIT_TR2_CONFIG_PARAMS" can be set to a
> - * list of patterns considered important.  For example:
> + * Use the TR2_SYSENV_CFG_PARAM setting to register a list of patterns
> + * configured important.  For example:
>   *
>   *    GIT_TR2_CONFIG_PARAMS="core.*,remote.*.url"
>   *
> diff --git a/trace2/tr2_cfg.c b/trace2/tr2_cfg.c
> index b329921ac5..caa7f06948 100644
> --- a/trace2/tr2_cfg.c
> +++ b/trace2/tr2_cfg.c
> @@ -1,8 +1,7 @@
>  #include "cache.h"
>  #include "config.h"
> -#include "tr2_cfg.h"
> -
> -#define TR2_ENVVAR_CFG_PARAM "GIT_TR2_CONFIG_PARAMS"
> +#include "trace2/tr2_cfg.h"
> +#include "trace2/tr2_sysenv.h"
>
>  static struct strbuf **tr2_cfg_patterns;
>  static int tr2_cfg_count_patterns;
> @@ -21,7 +20,7 @@ static int tr2_cfg_load_patterns(void)
>  		return tr2_cfg_count_patterns;
>  	tr2_cfg_loaded = 1;
>
> -	envvar = getenv(TR2_ENVVAR_CFG_PARAM);
> +	envvar = tr2_sysenv_get(TR2_SYSENV_CFG_PARAM);
>  	if (!envvar || !*envvar)
>  		return tr2_cfg_count_patterns;
>
> diff --git a/trace2/tr2_dst.c b/trace2/tr2_dst.c
> index fd490a43ad..575cd69aa9 100644
> --- a/trace2/tr2_dst.c
> +++ b/trace2/tr2_dst.c
> @@ -1,5 +1,6 @@
>  #include "cache.h"
>  #include "trace2/tr2_dst.h"
> +#include "trace2/tr2_sysenv.h"
>
>  /*
>   * If a Trace2 target cannot be opened for writing, we should issue a
> @@ -7,17 +8,13 @@
>   * or socket and beyond the user's control -- especially since every
>   * git command (and sub-command) will print the message.  So we silently
>   * eat these warnings and just discard the trace data.
> - *
> - * Enable the following environment variable to see these warnings.
>   */
> -#define TR2_ENVVAR_DST_DEBUG "GIT_TR2_DST_DEBUG"
> -
>  static int tr2_dst_want_warning(void)
>  {
>  	static int tr2env_dst_debug = -1;
>
>  	if (tr2env_dst_debug == -1) {
> -		const char *env_value = getenv(TR2_ENVVAR_DST_DEBUG);
> +		const char *env_value = tr2_sysenv_get(TR2_SYSENV_DST_DEBUG);
>  		if (!env_value || !*env_value)
>  			tr2env_dst_debug = 0;
>  		else
> @@ -42,7 +39,9 @@ static int tr2_dst_try_path(struct tr2_dst *dst, const char *tgt_value)
>  	if (fd == -1) {
>  		if (tr2_dst_want_warning())
>  			warning("trace2: could not open '%s' for '%s' tracing: %s",
> -				tgt_value, dst->env_var_name, strerror(errno));
> +				tgt_value,
> +				tr2_sysenv_display_name(dst->sysenv_var),
> +				strerror(errno));
>
>  		tr2_dst_trace_disable(dst);
>  		return 0;
> @@ -116,7 +115,7 @@ static int tr2_dst_try_unix_domain_socket(struct tr2_dst *dst,
>  	if (!path || !*path) {
>  		if (tr2_dst_want_warning())
>  			warning("trace2: invalid AF_UNIX value '%s' for '%s' tracing",
> -				tgt_value, dst->env_var_name);
> +				tgt_value, tr2_sysenv_display_name(dst->sysenv_var));
>
>  		tr2_dst_trace_disable(dst);
>  		return 0;
> @@ -126,7 +125,7 @@ static int tr2_dst_try_unix_domain_socket(struct tr2_dst *dst,
>  	    strlen(path) >= sizeof(((struct sockaddr_un *)0)->sun_path)) {
>  		if (tr2_dst_want_warning())
>  			warning("trace2: invalid AF_UNIX path '%s' for '%s' tracing",
> -				path, dst->env_var_name);
> +				path, tr2_sysenv_display_name(dst->sysenv_var));
>
>  		tr2_dst_trace_disable(dst);
>  		return 0;
> @@ -148,7 +147,7 @@ static int tr2_dst_try_unix_domain_socket(struct tr2_dst *dst,
>  error:
>  	if (tr2_dst_want_warning())
>  		warning("trace2: could not connect to socket '%s' for '%s' tracing: %s",
> -			path, dst->env_var_name, strerror(e));
> +			path, tr2_sysenv_display_name(dst->sysenv_var), strerror(e));
>
>  	tr2_dst_trace_disable(dst);
>  	return 0;
> @@ -168,7 +167,7 @@ static void tr2_dst_malformed_warning(struct tr2_dst *dst,
>  	struct strbuf buf = STRBUF_INIT;
>
>  	strbuf_addf(&buf, "trace2: unknown value for '%s': '%s'",
> -		    dst->env_var_name, tgt_value);
> +		    tr2_sysenv_display_name(dst->sysenv_var), tgt_value);
>  	warning("%s", buf.buf);
>
>  	strbuf_release(&buf);
> @@ -184,7 +183,7 @@ int tr2_dst_get_trace_fd(struct tr2_dst *dst)
>
>  	dst->initialized = 1;
>
> -	tgt_value = getenv(dst->env_var_name);
> +	tgt_value = tr2_sysenv_get(dst->sysenv_var);
>
>  	if (!tgt_value || !strcmp(tgt_value, "") || !strcmp(tgt_value, "0") ||
>  	    !strcasecmp(tgt_value, "false")) {
> @@ -246,7 +245,8 @@ void tr2_dst_write_line(struct tr2_dst *dst, struct strbuf *buf_line)
>  		return;
>
>  	if (tr2_dst_want_warning())
> -		warning("unable to write trace to '%s': %s", dst->env_var_name,
> +		warning("unable to write trace to '%s': %s",
> +			tr2_sysenv_display_name(dst->sysenv_var),
>  			strerror(errno));
>  	tr2_dst_trace_disable(dst);
>  }
> diff --git a/trace2/tr2_dst.h b/trace2/tr2_dst.h
> index 9a64f05b02..3adf3bac13 100644
> --- a/trace2/tr2_dst.h
> +++ b/trace2/tr2_dst.h
> @@ -2,9 +2,10 @@
>  #define TR2_DST_H
>
>  struct strbuf;
> +#include "trace2/tr2_sysenv.h"
>
>  struct tr2_dst {
> -	const char *const env_var_name;
> +	enum tr2_sysenv_variable sysenv_var;
>  	int fd;
>  	unsigned int initialized : 1;
>  	unsigned int need_close : 1;
> diff --git a/trace2/tr2_sysenv.c b/trace2/tr2_sysenv.c
> new file mode 100644
> index 0000000000..656613e371
> --- /dev/null
> +++ b/trace2/tr2_sysenv.c
> @@ -0,0 +1,125 @@
> +#include "cache.h"
> +#include "config.h"
> +#include "dir.h"
> +#include "tr2_sysenv.h"
> +
> +/*
> + * Each entry represents a trace2 setting.
> + * See Documentation/technical/api-trace2.txt
> + */
> +struct tr2_sysenv_entry {
> +	const char *env_var_name;
> +	const char *git_config_name;
> +
> +	char *value;
> +	unsigned int getenv_called : 1;
> +};
> +
> +/*
> + * This table must match "enum tr2_sysenv_variable" in tr2_sysenv.h.
> + * These strings are constant and must match the published names as
> + * described in the documentation.
> + *
> + * We do not define entries for the GIT_TR2_PARENT_* environment
> + * variables because they are transient and used to pass information
> + * from parent to child git processes, rather than settings.
> + */
> +/* clang-format off */
> +static struct tr2_sysenv_entry tr2_sysenv_settings[] = {
> +	{ "GIT_TR2_CONFIG_PARAMS",   "trace2.configparams"     },
> +
> +	{ "GIT_TR2_DST_DEBUG",       "trace2.destinationdebug" },
> +
> +	{ "GIT_TR2",                 "trace2.normaltarget"     },
> +	{ "GIT_TR2_BRIEF",           "trace2.normalbrief"      },
> +
> +	{ "GIT_TR2_EVENT",           "trace2.eventtarget"      },
> +	{ "GIT_TR2_EVENT_BRIEF",     "trace2.eventbrief"       },
> +	{ "GIT_TR2_EVENT_NESTING",   "trace2.eventnesting"     },
> +
> +	{ "GIT_TR2_PERF",            "trace2.perftarget"       },
> +	{ "GIT_TR2_PERF_BRIEF",      "trace2.perfbrief"        },
> +};
> +/* clang-format on */
> +
> +static int tr2_sysenv_cb(const char *key, const char *value, void *d)
> +{
> +	int k;
> +

I added:

	if (!starts_with(key, "trace2."))
		return 0;

Here, and everything works as expected. I think that's a good
idea. Makes this O(n) over N config keys instead of O(n*x) where x = num
entries in tr2_sysenv_settings.

> +	for (k = 0; k < ARRAY_SIZE(tr2_sysenv_settings); k++) {
> +		if (!strcmp(key, tr2_sysenv_settings[k].git_config_name)) {
> +			free(tr2_sysenv_settings[k].value);
> +			tr2_sysenv_settings[k].value = xstrdup(value);
> +			return 0;
> +		}
> +	}
> +
> +	return 0;
> +}
> +
> +/*
> + * Load Trace2 settings from the system config (usually "/etc/gitconfig"
> + * unless we were built with a runtime-prefix).  These are intended to
> + * define the default values for Trace2 as requested by the administrator.
> + */
> +void tr2_sysenv_load(void)
> +{
> +	const char *system_config_pathname;
> +	const char *test_pathname;
> +
> +	system_config_pathname = git_etc_gitconfig();
> +
> +	test_pathname = getenv("GIT_TEST_TR2_SYSTEM_CONFIG");
> +	if (test_pathname) {
> +		if (!*test_pathname || !strcmp(test_pathname, "0"))
> +			return; /* disable use of system config */
> +
> +		/* mock it with given test file */
> +		system_config_pathname = test_pathname;
> +	}
> +
> +	if (file_exists(system_config_pathname))
> +		git_config_from_file(tr2_sysenv_cb, system_config_pathname,
> +				     NULL);

Maybe this isn't worth it, but this "file_exists" thing is something we
could abstract in the config machinery (or maybe passing via
"config_options" makes more sense):

    diff --git a/config.c b/config.c
    index 0f0cdd8c0f..ea625a508f 100644
    --- a/config.c
    +++ b/config.c
    @@ -1549,12 +1549,15 @@ static int git_config_from_stdin(config_fn_t fn, void *data)

     int git_config_from_file_with_options(config_fn_t fn, const char *filename,
     				      void *data,
    -				      const struct config_options *opts)
    +				      const struct config_options *opts,
    +				      int or_warn)
     {
     	int ret = -1;
     	FILE *f;

    -	f = fopen_or_warn(filename, "r");
    +	f = or_warn
    +		? fopen_or_warn(filename, "r")
    +		: fopen(filename, "r");
     	if (f) {
     		ret = do_config_from_file(fn, CONFIG_ORIGIN_FILE, filename,
     					  filename, f, data, opts);
    @@ -1565,7 +1568,7 @@ int git_config_from_file_with_options(config_fn_t fn, const char *filename,

     int git_config_from_file(config_fn_t fn, const char *filename, void *data)
     {
    -	return git_config_from_file_with_options(fn, filename, data, NULL);
    +	return git_config_from_file_with_options(fn, filename, data, NULL, 1);
     }

     int git_config_from_mem(config_fn_t fn,
    @@ -2787,7 +2790,7 @@ int git_config_set_multivar_in_file_gently(const char *config_filename,
     		 */
     		if (git_config_from_file_with_options(store_aux,
     						      config_filename,
    -						      &store, &opts)) {
    +						      &store, &opts, 1)) {
     			error(_("invalid config file %s"), config_filename);
     			ret = CONFIG_INVALID_FILE;
     			goto out_free;
    diff --git a/config.h b/config.h
    index ee5d3fa7b4..52e93e6cdc 100644
    --- a/config.h
    +++ b/config.h
    @@ -72,7 +72,8 @@ extern int git_default_config(const char *, const char *, void *);
     extern int git_config_from_file(config_fn_t fn, const char *, void *);
     extern int git_config_from_file_with_options(config_fn_t fn, const char *,
     					     void *,
    -					     const struct config_options *);
    +					     const struct config_options *,
    +					     int);
     extern int git_config_from_mem(config_fn_t fn,
     			       const enum config_origin_type,
     			       const char *name,
    diff --git a/trace2/tr2_sysenv.c b/trace2/tr2_sysenv.c
    index 656613e371..25a9c19d20 100644
    --- a/trace2/tr2_sysenv.c
    +++ b/trace2/tr2_sysenv.c
    @@ -78,9 +81,9 @@ void tr2_sysenv_load(void)
     		system_config_pathname = test_pathname;
     	}

    -	if (file_exists(system_config_pathname))
    -		git_config_from_file(tr2_sysenv_cb, system_config_pathname,
    -				     NULL);
    +	git_config_from_file_with_options(tr2_sysenv_cb,
    +					  system_config_pathname, NULL, NULL,
    +					  0);
     }

     /*


> +}
> +
> +/*
> + * Return the value for the requested setting.  Start with the /etc/gitconfig
> + * value and allow the corresponding environment variable to override it.
> + */
> +const char *tr2_sysenv_get(enum tr2_sysenv_variable var)
> +{
> +	if (var >= TR2_SYSENV_MUST_BE_LAST)
> +		BUG("tr2_sysenv_get invalid var '%d'", var);
> +
> +	if (!tr2_sysenv_settings[var].getenv_called) {
> +		const char *v = getenv(tr2_sysenv_settings[var].env_var_name);
> +		if (v && *v) {
> +			free(tr2_sysenv_settings[var].value);
> +			tr2_sysenv_settings[var].value = xstrdup(v);
> +		}
> +		tr2_sysenv_settings[var].getenv_called = 1;
> +	}
> +
> +	return tr2_sysenv_settings[var].value;
> +}
> +
> +/*
> + * Return a friendly name for this setting that is suitable for printing
> + * in an error messages.
> + */
> +const char *tr2_sysenv_display_name(enum tr2_sysenv_variable var)
> +{
> +	if (var >= TR2_SYSENV_MUST_BE_LAST)
> +		BUG("tr2_sysenv_get invalid var '%d'", var);
> +
> +	return tr2_sysenv_settings[var].env_var_name;
> +}
> +
> +void tr2_sysenv_release(void)
> +{
> +	int k;
> +
> +	for (k = 0; k < ARRAY_SIZE(tr2_sysenv_settings); k++)
> +		free(tr2_sysenv_settings[k].value);
> +}
> diff --git a/trace2/tr2_sysenv.h b/trace2/tr2_sysenv.h
> new file mode 100644
> index 0000000000..369b20bd87
> --- /dev/null
> +++ b/trace2/tr2_sysenv.h
> @@ -0,0 +1,36 @@
> +#ifndef TR2_SYSENV_H
> +#define TR2_SYSENV_H
> +
> +/*
> + * The Trace2 settings that can be loaded from /etc/gitconfig
> + * and/or user environment variables.
> + *
> + * Note that this set does not contain any of the transient
> + * environment variables used to pass information from parent
> + * to child git processes, such "GIT_TR2_PARENT_SID".
> + */
> +enum tr2_sysenv_variable {
> +	TR2_SYSENV_CFG_PARAM = 0,
> +
> +	TR2_SYSENV_DST_DEBUG,
> +
> +	TR2_SYSENV_NORMAL,
> +	TR2_SYSENV_NORMAL_BRIEF,
> +
> +	TR2_SYSENV_EVENT,
> +	TR2_SYSENV_EVENT_BRIEF,
> +	TR2_SYSENV_EVENT_NESTING,
> +
> +	TR2_SYSENV_PERF,
> +	TR2_SYSENV_PERF_BRIEF,
> +
> +	TR2_SYSENV_MUST_BE_LAST
> +};
> +
> +void tr2_sysenv_load(void);
> +
> +const char *tr2_sysenv_get(enum tr2_sysenv_variable);
> +const char *tr2_sysenv_display_name(enum tr2_sysenv_variable var);
> +void tr2_sysenv_release(void);
> +
> +#endif /* TR2_SYSENV_H */
> diff --git a/trace2/tr2_tgt_event.c b/trace2/tr2_tgt_event.c
> index 89a4d3ae9a..bb6e323953 100644
> --- a/trace2/tr2_tgt_event.c
> +++ b/trace2/tr2_tgt_event.c
> @@ -6,10 +6,11 @@
>  #include "trace2/tr2_dst.h"
>  #include "trace2/tr2_tbuf.h"
>  #include "trace2/tr2_sid.h"
> +#include "trace2/tr2_sysenv.h"
>  #include "trace2/tr2_tgt.h"
>  #include "trace2/tr2_tls.h"
>
> -static struct tr2_dst tr2dst_event = { "GIT_TR2_EVENT", 0, 0, 0 };
> +static struct tr2_dst tr2dst_event = { TR2_SYSENV_EVENT, 0, 0, 0 };
>
>  /*
>   * The version number of the JSON data generated by the EVENT target
> @@ -28,17 +29,15 @@ static struct tr2_dst tr2dst_event = { "GIT_TR2_EVENT", 0, 0, 0 };
>   * are primarily intended for the performance target during debugging.
>   *
>   * Some of the outer-most messages, however, may be of interest to the
> - * event target.  Set this environment variable to a larger integer for
> - * more detail in the event target.
> + * event target.  Use the TR2_SYSENV_EVENT_NESTING setting to increase
> + * region details in the event target.
>   */
> -#define TR2_ENVVAR_EVENT_NESTING "GIT_TR2_EVENT_NESTING"
>  static int tr2env_event_nesting_wanted = 2;
>
>  /*
> - * Set this environment variable to true to omit the <time>, <file>, and
> + * Use the TR2_SYSENV_EVENT_BRIEF to omit the <time>, <file>, and
>   * <line> fields from most events.
>   */
> -#define TR2_ENVVAR_EVENT_BRIEF "GIT_TR2_EVENT_BRIEF"
>  static int tr2env_event_brief;
>
>  static int fn_init(void)
> @@ -46,17 +45,17 @@ static int fn_init(void)
>  	int want = tr2_dst_trace_want(&tr2dst_event);
>  	int want_nesting;
>  	int want_brief;
> -	char *nesting;
> -	char *brief;
> +	const char *nesting;
> +	const char *brief;
>
>  	if (!want)
>  		return want;
>
> -	nesting = getenv(TR2_ENVVAR_EVENT_NESTING);
> +	nesting = tr2_sysenv_get(TR2_SYSENV_EVENT_NESTING);
>  	if (nesting && ((want_nesting = atoi(nesting)) > 0))
>  		tr2env_event_nesting_wanted = want_nesting;
>
> -	brief = getenv(TR2_ENVVAR_EVENT_BRIEF);
> +	brief = tr2_sysenv_get(TR2_SYSENV_EVENT_BRIEF);
>  	if (brief && ((want_brief = atoi(brief)) > 0))
>  		tr2env_event_brief = want_brief;

A lot of this pre-dates this patch, but I wonder if the whole of trace2
couldn't make more use of config.c's bool parsing for things like
these. Maybe by having a "cfg_type" enum & parsed_value void* in
tr2_sysenv_entry?

> diff --git a/trace2/tr2_tgt_normal.c b/trace2/tr2_tgt_normal.c
> index 57f3e18f5b..3364223805 100644
> --- a/trace2/tr2_tgt_normal.c
> +++ b/trace2/tr2_tgt_normal.c
> @@ -4,19 +4,19 @@
>  #include "quote.h"
>  #include "version.h"
>  #include "trace2/tr2_dst.h"
> +#include "trace2/tr2_sysenv.h"
>  #include "trace2/tr2_tbuf.h"
>  #include "trace2/tr2_tgt.h"
>  #include "trace2/tr2_tls.h"
>
> -static struct tr2_dst tr2dst_normal = { "GIT_TR2", 0, 0, 0 };
> +static struct tr2_dst tr2dst_normal = { TR2_SYSENV_NORMAL, 0, 0, 0 };
>
>  /*
> - * Set this environment variable to true to omit the "<time> <file>:<line>"
> + * Use the TR2_SYSENV_NORMAL_BRIEF setting to omit the "<time> <file>:<line>"
>   * fields from each line written to the builtin normal target.
>   *
>   * Unit tests may want to use this to help with testing.
>   */
> -#define TR2_ENVVAR_NORMAL_BRIEF "GIT_TR2_BRIEF"
>  static int tr2env_normal_brief;
>
>  #define TR2FMT_NORMAL_FL_WIDTH (50)
> @@ -25,12 +25,12 @@ static int fn_init(void)
>  {
>  	int want = tr2_dst_trace_want(&tr2dst_normal);
>  	int want_brief;
> -	char *brief;
> +	const char *brief;
>
>  	if (!want)
>  		return want;
>
> -	brief = getenv(TR2_ENVVAR_NORMAL_BRIEF);
> +	brief = tr2_sysenv_get(TR2_SYSENV_NORMAL_BRIEF);
>  	if (brief && *brief &&
>  	    ((want_brief = git_parse_maybe_bool(brief)) != -1))
>  		tr2env_normal_brief = want_brief;


> diff --git a/trace2/tr2_tgt_perf.c b/trace2/tr2_tgt_perf.c
> index 9c3b4d8a0f..1ad781c32e 100644
> --- a/trace2/tr2_tgt_perf.c
> +++ b/trace2/tr2_tgt_perf.c
> @@ -6,19 +6,19 @@
>  #include "json-writer.h"
>  #include "trace2/tr2_dst.h"
>  #include "trace2/tr2_sid.h"
> +#include "trace2/tr2_sysenv.h"
>  #include "trace2/tr2_tbuf.h"
>  #include "trace2/tr2_tgt.h"
>  #include "trace2/tr2_tls.h"
>
> -static struct tr2_dst tr2dst_perf = { "GIT_TR2_PERF", 0, 0, 0 };
> +static struct tr2_dst tr2dst_perf = { TR2_SYSENV_PERF, 0, 0, 0 };
>
>  /*
> - * Set this environment variable to true to omit the "<time> <file>:<line>"
> + * Use TR2_SYSENV_PERF_BRIEF to omit the "<time> <file>:<line>"
>   * fields from each line written to the builtin performance target.
>   *
>   * Unit tests may want to use this to help with testing.
>   */
> -#define TR2_ENVVAR_PERF_BRIEF "GIT_TR2_PERF_BRIEF"
>  static int tr2env_perf_brief;
>
>  #define TR2FMT_PERF_FL_WIDTH (50)
> @@ -36,14 +36,14 @@ static int fn_init(void)
>  {
>  	int want = tr2_dst_trace_want(&tr2dst_perf);
>  	int want_brief;
> -	char *brief;
> +	const char *brief;
>
>  	if (!want)
>  		return want;
>
>  	strbuf_addchars(&dots, '.', TR2_DOTS_BUFFER_SIZE);
>
> -	brief = getenv(TR2_ENVVAR_PERF_BRIEF);
> +	brief = tr2_sysenv_get(TR2_SYSENV_PERF_BRIEF);
>  	if (brief && *brief &&
>  	    ((want_brief = git_parse_maybe_bool(brief)) != -1))
>  		tr2env_perf_brief = want_brief;

^ permalink raw reply	[flat|nested] 68+ messages in thread

* Re: [PATCH 4/4] trace2: use system config for default trace2 settings
  2019-03-28 14:36   ` Ævar Arnfjörð Bjarmason
@ 2019-03-28 18:50     ` Jeff Hostetler
  0 siblings, 0 replies; 68+ messages in thread
From: Jeff Hostetler @ 2019-03-28 18:50 UTC (permalink / raw)
  To: Ævar Arnfjörð Bjarmason, Jeff Hostetler via GitGitGadget
  Cc: git, peff, jrnieder, steadmon, Junio C Hamano, Jeff Hostetler



On 3/28/2019 10:36 AM, Ævar Arnfjörð Bjarmason wrote:
> 
> On Thu, Mar 28 2019, Jeff Hostetler via GitGitGadget wrote:
> 
> Thanks for working on this!
> 
> Haven't given this any deep testing. Just some observations:
> 
>> From: Jeff Hostetler <jeffhost@microsoft.com>
>>
>> Teach git to read the system config (usually "/etc/gitconfig") for
>> default Trace2 settings.  This allows system-wide Trace2 settings to
>> be installed and inherited to make it easier to manage a collection of
>> systems.
[...]

>> diff --git a/trace2/tr2_sysenv.c b/trace2/tr2_sysenv.c
>> new file mode 100644
>> index 0000000000..656613e371
>> --- /dev/null
[...]

>> +/* clang-format off */
>> +static struct tr2_sysenv_entry tr2_sysenv_settings[] = {
>> +	{ "GIT_TR2_CONFIG_PARAMS",   "trace2.configparams"     },
>> +
>> +	{ "GIT_TR2_DST_DEBUG",       "trace2.destinationdebug" },
>> +
>> +	{ "GIT_TR2",                 "trace2.normaltarget"     },
>> +	{ "GIT_TR2_BRIEF",           "trace2.normalbrief"      },
>> +
>> +	{ "GIT_TR2_EVENT",           "trace2.eventtarget"      },
>> +	{ "GIT_TR2_EVENT_BRIEF",     "trace2.eventbrief"       },
>> +	{ "GIT_TR2_EVENT_NESTING",   "trace2.eventnesting"     },
>> +
>> +	{ "GIT_TR2_PERF",            "trace2.perftarget"       },
>> +	{ "GIT_TR2_PERF_BRIEF",      "trace2.perfbrief"        },
>> +};
>> +/* clang-format on */
>> +
>> +static int tr2_sysenv_cb(const char *key, const char *value, void *d)
>> +{
>> +	int k;
>> +
> 
> I added:
> 
> 	if (!starts_with(key, "trace2."))
> 		return 0;
> 
> Here, and everything works as expected. I think that's a good
> idea. Makes this O(n) over N config keys instead of O(n*x) where x = num
> entries in tr2_sysenv_settings.

Good idea.  Thanks!

> 
>> +	for (k = 0; k < ARRAY_SIZE(tr2_sysenv_settings); k++) {
>> +		if (!strcmp(key, tr2_sysenv_settings[k].git_config_name)) {
>> +			free(tr2_sysenv_settings[k].value);
>> +			tr2_sysenv_settings[k].value = xstrdup(value);
>> +			return 0;
>> +		}
>> +	}
>> +
>> +	return 0;
>> +}
>> +
>> +/*
>> + * Load Trace2 settings from the system config (usually "/etc/gitconfig"
>> + * unless we were built with a runtime-prefix).  These are intended to
>> + * define the default values for Trace2 as requested by the administrator.
>> + */
>> +void tr2_sysenv_load(void)
>> +{
>> +	const char *system_config_pathname;
>> +	const char *test_pathname;
>> +
>> +	system_config_pathname = git_etc_gitconfig();
>> +
>> +	test_pathname = getenv("GIT_TEST_TR2_SYSTEM_CONFIG");
>> +	if (test_pathname) {
>> +		if (!*test_pathname || !strcmp(test_pathname, "0"))
>> +			return; /* disable use of system config */
>> +
>> +		/* mock it with given test file */
>> +		system_config_pathname = test_pathname;
>> +	}
>> +
>> +	if (file_exists(system_config_pathname))
>> +		git_config_from_file(tr2_sysenv_cb, system_config_pathname,
>> +				     NULL);
> 
> Maybe this isn't worth it, but this "file_exists" thing is something we
> could abstract in the config machinery (or maybe passing via
> "config_options" makes more sense):
[...]

This is a good idea, but I think I'll save this for a future effort
rather than add it to the current patch series.  It just seems outside
of my scope right now and adds to the footprint of this series.

[...]
>>
>> -	nesting = getenv(TR2_ENVVAR_EVENT_NESTING);
>> +	nesting = tr2_sysenv_get(TR2_SYSENV_EVENT_NESTING);
>>   	if (nesting && ((want_nesting = atoi(nesting)) > 0))
>>   		tr2env_event_nesting_wanted = want_nesting;
>>
>> -	brief = getenv(TR2_ENVVAR_EVENT_BRIEF);
>> +	brief = tr2_sysenv_get(TR2_SYSENV_EVENT_BRIEF);
>>   	if (brief && ((want_brief = atoi(brief)) > 0))
>>   		tr2env_event_brief = want_brief;
> 
> A lot of this pre-dates this patch, but I wonder if the whole of trace2
> couldn't make more use of config.c's bool parsing for things like
> these. Maybe by having a "cfg_type" enum & parsed_value void* in
> tr2_sysenv_entry?

I converted the "brief" instances in the normal and perf targets to
use git_parse_maybe_bool() already, but I missed this one.

The nesting one above is actually an integer value rather than a bool.
I'll rename the variables in the re-roll to clarify that.


[...]
>> -	brief = getenv(TR2_ENVVAR_NORMAL_BRIEF);
>> +	brief = tr2_sysenv_get(TR2_SYSENV_NORMAL_BRIEF);
>>   	if (brief && *brief &&
>>   	    ((want_brief = git_parse_maybe_bool(brief)) != -1))
>>   		tr2env_normal_brief = want_brief;
[...]
>> -	brief = getenv(TR2_ENVVAR_PERF_BRIEF);
>> +	brief = tr2_sysenv_get(TR2_SYSENV_PERF_BRIEF);
>>   	if (brief && *brief &&
>>   	    ((want_brief = git_parse_maybe_bool(brief)) != -1))
>>   		tr2env_perf_brief = want_brief;


Thanks for the review.
I'll push up another version shortly.

Jeff

^ permalink raw reply	[flat|nested] 68+ messages in thread

* Re: [PATCH 4/4] trace2: use system config for default trace2 settings
  2019-03-28 13:31 ` [PATCH 4/4] trace2: use system config for default trace2 settings Jeff Hostetler via GitGitGadget
  2019-03-28 14:36   ` Ævar Arnfjörð Bjarmason
@ 2019-03-28 21:28   ` Josh Steadmon
  1 sibling, 0 replies; 68+ messages in thread
From: Josh Steadmon @ 2019-03-28 21:28 UTC (permalink / raw)
  To: Jeff Hostetler via GitGitGadget
  Cc: git, gitster, peff, jrnieder, avarab, Jeff Hostetler

One quick comment:

On 2019.03.28 06:31, Jeff Hostetler via GitGitGadget wrote:
[...]
> diff --git a/trace2.h b/trace2.h
> index 8f89e70c44..cda8349058 100644
> --- a/trace2.h
> +++ b/trace2.h
> @@ -38,7 +38,8 @@ void trace2_initialize_clock(void);
>  
>  /*
>   * Initialize TRACE2 tracing facility if any of the builtin TRACE2
> - * targets are enabled in the environment.  Emits a 'version' event.
> + * targets are enabled in the system config or the environment.
> + * Emits a 'version' event.
>   *
>   * Cleanup/Termination is handled automatically by a registered
>   * atexit() routine.
> @@ -125,8 +126,8 @@ void trace2_cmd_alias_fl(const char *file, int line, const char *alias,
>   * Emit one or more 'def_param' events for "interesting" configuration
>   * settings.
>   *
> - * The environment variable "GIT_TR2_CONFIG_PARAMS" can be set to a
> - * list of patterns considered important.  For example:
> + * Use the TR2_SYSENV_CFG_PARAM setting to register a list of patterns
> + * configured important.  For example:
>   *
>   *    GIT_TR2_CONFIG_PARAMS="core.*,remote.*.url"
>   *

Looks like the example needs to be updated with the new var name as
well.

^ permalink raw reply	[flat|nested] 68+ messages in thread

* [PATCH v2 0/7] trace2: load trace2 settings from system config
  2019-03-28 13:30 [PATCH 0/4] trace2: load trace2 settings from system config Jeff Hostetler via GitGitGadget
                   ` (3 preceding siblings ...)
  2019-03-28 13:31 ` [PATCH 4/4] trace2: use system config for default trace2 settings Jeff Hostetler via GitGitGadget
@ 2019-03-29 17:04 ` Jeff Hostetler via GitGitGadget
  2019-03-29 17:04   ` [PATCH v2 1/7] trace2: refactor setting process starting time Jeff Hostetler via GitGitGadget
                     ` (8 more replies)
  4 siblings, 9 replies; 68+ messages in thread
From: Jeff Hostetler via GitGitGadget @ 2019-03-29 17:04 UTC (permalink / raw)
  To: git; +Cc: gitster, peff, jrnieder, steadmon, avarab, Junio C Hamano

Here is version 2. It addresses most the V1 comments WRT the system config
changes.

It also addresses the format and uniqueness of the SID as discussed in [1].
The SID now containes: the UTC date/time, part of SHA1 of the hostname, and
the PID and is formatted to make it safe for filenames.

It also contains (a somewhat unrelated platform-specific) commit to report
total process memory usage at exit. This is helpful when looking for
problematic commands that might have scaling problems.

[1] 
https://public-inbox.org/git/51e88650-8667-df1f-13ef-4537f2e70346@jeffhostetler.com/T/#m6b4e6f2b0374d5ba88de8d0350ce6bf51b28d7da


----------------------------------------------------------------------------

Teach git to load default Trace2 settings from the system config (usually
"/etc/gitconfig"). The existing GIT_TR2_* environment variables can be used
to override the new system defaults. It also includes a little startup
refactoring.

Note: I found interactive testing of this feature to be awkward on some
platforms because of the use of prefix- or runtime-prefix-relative locations
for the system configuration. It was easy to accidentally use an officially
installed version of git to set a system config variable in the official
system config directory; and then when testing with the test version of git,
that value would not be seen because it was looking for the system config
file in a different directory.

Jeff Hostetler (7):
  trace2: refactor setting process starting time
  trace2: add absolute elapsed time to start event
  trace2: find exec-dir before trace2 initialization
  trace2: use system config for default trace2 settings
  trace2: report peak memory usage of the process
  trace2: clarify UTC datetime formatting
  trace2: make SIDs more unique

 Documentation/technical/api-trace2.txt   |  66 +++++++++---
 Makefile                                 |   1 +
 common-main.c                            |   8 +-
 compat/mingw.c                           |   2 +
 compat/win32/trace2_win32_process_info.c |  50 ++++++++-
 t/t0210-trace2-normal.sh                 |  41 +++++++-
 t/t0211-trace2-perf.sh                   |  53 ++++++++--
 t/t0212-trace2-event.sh                  |  52 ++++++++-
 trace2.c                                 |  21 +++-
 trace2.h                                 |  43 ++++++--
 trace2/tr2_cfg.c                         |   7 +-
 trace2/tr2_dst.c                         |  24 ++---
 trace2/tr2_dst.h                         |   3 +-
 trace2/tr2_sid.c                         |  39 ++++++-
 trace2/tr2_sysenv.c                      | 128 +++++++++++++++++++++++
 trace2/tr2_sysenv.h                      |  36 +++++++
 trace2/tr2_tbuf.c                        |  20 +++-
 trace2/tr2_tbuf.h                        |   5 +-
 trace2/tr2_tgt.h                         |   1 +
 trace2/tr2_tgt_event.c                   |  53 +++++-----
 trace2/tr2_tgt_normal.c                  |  19 ++--
 trace2/tr2_tgt_perf.c                    |  23 ++--
 trace2/tr2_tls.c                         |  38 ++++---
 trace2/tr2_tls.h                         |   8 +-
 24 files changed, 604 insertions(+), 137 deletions(-)
 create mode 100644 trace2/tr2_sysenv.c
 create mode 100644 trace2/tr2_sysenv.h


base-commit: 041f5ea1cf987a4068ef5f39ba0a09be85952064
Published-As: https://github.com/gitgitgadget/git/releases/tag/pr-169%2Fjeffhostetler%2Fcore-tr2-startup-and-sysenv-v2
Fetch-It-Via: git fetch https://github.com/gitgitgadget/git pr-169/jeffhostetler/core-tr2-startup-and-sysenv-v2
Pull-Request: https://github.com/gitgitgadget/git/pull/169

Range-diff vs v1:

 1:  7f1a347322 = 1:  7f1a347322 trace2: refactor setting process starting time
 2:  c15f783c26 = 2:  c15f783c26 trace2: add absolute elapsed time to start event
 3:  d4023acde7 = 3:  d4023acde7 trace2: find exec-dir before trace2 initialization
 4:  7e0d4e20fb ! 4:  d048f3ffb8 trace2: use system config for default trace2 settings
     @@ -332,11 +332,16 @@
        *
      - * The environment variable "GIT_TR2_CONFIG_PARAMS" can be set to a
      - * list of patterns considered important.  For example:
     -+ * Use the TR2_SYSENV_CFG_PARAM setting to register a list of patterns
     -+ * configured important.  For example:
     -  *
     -  *    GIT_TR2_CONFIG_PARAMS="core.*,remote.*.url"
     +- *
     +- *    GIT_TR2_CONFIG_PARAMS="core.*,remote.*.url"
     ++ * Use the TR2_SYSENV_CFG_PARAM setting to register a comma-separated
     ++ * list of patterns configured important.  For example:
     ++ *     git config --system trace2.configParams 'core.*,remote.*.url'
     ++ * or:
     ++ *     GIT_TR2_CONFIG_PARAMS=core.*,remote.*.url"
        *
     +  * Note: this routine does a read-only iteration on the config data
     +  * (using read_early_config()), so it must not be called until enough
      
       diff --git a/trace2/tr2_cfg.c b/trace2/tr2_cfg.c
       --- a/trace2/tr2_cfg.c
     @@ -527,6 +532,9 @@
      +{
      +	int k;
      +
     ++	if (!starts_with(key, "trace2."))
     ++		return 0;
     ++
      +	for (k = 0; k < ARRAY_SIZE(tr2_sysenv_settings); k++) {
      +		if (!strcmp(key, tr2_sysenv_settings[k].git_config_name)) {
      +			free(tr2_sysenv_settings[k].value);
     @@ -673,7 +681,8 @@
      + * region details in the event target.
        */
      -#define TR2_ENVVAR_EVENT_NESTING "GIT_TR2_EVENT_NESTING"
     - static int tr2env_event_nesting_wanted = 2;
     +-static int tr2env_event_nesting_wanted = 2;
     ++static int tr2env_event_max_nesting_levels = 2;
       
       /*
      - * Set this environment variable to true to omit the <time>, <file>, and
     @@ -681,12 +690,14 @@
        * <line> fields from most events.
        */
      -#define TR2_ENVVAR_EVENT_BRIEF "GIT_TR2_EVENT_BRIEF"
     - static int tr2env_event_brief;
     +-static int tr2env_event_brief;
     ++static int tr2env_event_be_brief;
       
       static int fn_init(void)
     -@@
     + {
       	int want = tr2_dst_trace_want(&tr2dst_event);
     - 	int want_nesting;
     +-	int want_nesting;
     ++	int max_nesting;
       	int want_brief;
      -	char *nesting;
      -	char *brief;
     @@ -697,15 +708,74 @@
       		return want;
       
      -	nesting = getenv(TR2_ENVVAR_EVENT_NESTING);
     +-	if (nesting && ((want_nesting = atoi(nesting)) > 0))
     +-		tr2env_event_nesting_wanted = want_nesting;
      +	nesting = tr2_sysenv_get(TR2_SYSENV_EVENT_NESTING);
     - 	if (nesting && ((want_nesting = atoi(nesting)) > 0))
     - 		tr2env_event_nesting_wanted = want_nesting;
     ++	if (nesting && *nesting && ((max_nesting = atoi(nesting)) > 0))
     ++		tr2env_event_max_nesting_levels = max_nesting;
       
      -	brief = getenv(TR2_ENVVAR_EVENT_BRIEF);
     +-	if (brief && ((want_brief = atoi(brief)) > 0))
     +-		tr2env_event_brief = want_brief;
      +	brief = tr2_sysenv_get(TR2_SYSENV_EVENT_BRIEF);
     - 	if (brief && ((want_brief = atoi(brief)) > 0))
     - 		tr2env_event_brief = want_brief;
     ++	if (brief && *brief &&
     ++	    ((want_brief = git_parse_maybe_bool(brief)) != -1))
     ++		tr2env_event_be_brief = want_brief;
       
     + 	return want;
     + }
     +@@
     + 	/*
     + 	 * In brief mode, only emit <time> on these 2 event types.
     + 	 */
     +-	if (!tr2env_event_brief || !strcmp(event_name, "version") ||
     ++	if (!tr2env_event_be_brief || !strcmp(event_name, "version") ||
     + 	    !strcmp(event_name, "atexit")) {
     + 		tr2_tbuf_utc_time(&tb_now);
     + 		jw_object_string(jw, "time", tb_now.buf);
     + 	}
     + 
     +-	if (!tr2env_event_brief && file && *file) {
     ++	if (!tr2env_event_be_brief && file && *file) {
     + 		jw_object_string(jw, "file", file);
     + 		jw_object_intmax(jw, "line", line);
     + 	}
     +@@
     + {
     + 	const char *event_name = "region_enter";
     + 	struct tr2tls_thread_ctx *ctx = tr2tls_get_self();
     +-	if (ctx->nr_open_regions <= tr2env_event_nesting_wanted) {
     ++	if (ctx->nr_open_regions <= tr2env_event_max_nesting_levels) {
     + 		struct json_writer jw = JSON_WRITER_INIT;
     + 
     + 		jw_object_begin(&jw, 0);
     +@@
     + {
     + 	const char *event_name = "region_leave";
     + 	struct tr2tls_thread_ctx *ctx = tr2tls_get_self();
     +-	if (ctx->nr_open_regions <= tr2env_event_nesting_wanted) {
     ++	if (ctx->nr_open_regions <= tr2env_event_max_nesting_levels) {
     + 		struct json_writer jw = JSON_WRITER_INIT;
     + 		double t_rel = (double)us_elapsed_region / 1000000.0;
     + 
     +@@
     + {
     + 	const char *event_name = "data";
     + 	struct tr2tls_thread_ctx *ctx = tr2tls_get_self();
     +-	if (ctx->nr_open_regions <= tr2env_event_nesting_wanted) {
     ++	if (ctx->nr_open_regions <= tr2env_event_max_nesting_levels) {
     + 		struct json_writer jw = JSON_WRITER_INIT;
     + 		double t_abs = (double)us_elapsed_absolute / 1000000.0;
     + 		double t_rel = (double)us_elapsed_region / 1000000.0;
     +@@
     + {
     + 	const char *event_name = "data_json";
     + 	struct tr2tls_thread_ctx *ctx = tr2tls_get_self();
     +-	if (ctx->nr_open_regions <= tr2env_event_nesting_wanted) {
     ++	if (ctx->nr_open_regions <= tr2env_event_max_nesting_levels) {
     + 		struct json_writer jw = JSON_WRITER_INIT;
     + 		double t_abs = (double)us_elapsed_absolute / 1000000.0;
     + 		double t_rel = (double)us_elapsed_region / 1000000.0;
      
       diff --git a/trace2/tr2_tgt_normal.c b/trace2/tr2_tgt_normal.c
       --- a/trace2/tr2_tgt_normal.c
     @@ -730,9 +800,11 @@
        * Unit tests may want to use this to help with testing.
        */
      -#define TR2_ENVVAR_NORMAL_BRIEF "GIT_TR2_BRIEF"
     - static int tr2env_normal_brief;
     +-static int tr2env_normal_brief;
     ++static int tr2env_normal_be_brief;
       
       #define TR2FMT_NORMAL_FL_WIDTH (50)
     + 
      @@
       {
       	int want = tr2_dst_trace_want(&tr2dst_normal);
     @@ -747,7 +819,20 @@
      +	brief = tr2_sysenv_get(TR2_SYSENV_NORMAL_BRIEF);
       	if (brief && *brief &&
       	    ((want_brief = git_parse_maybe_bool(brief)) != -1))
     - 		tr2env_normal_brief = want_brief;
     +-		tr2env_normal_brief = want_brief;
     ++		tr2env_normal_be_brief = want_brief;
     + 
     + 	return want;
     + }
     +@@
     + {
     + 	strbuf_setlen(buf, 0);
     + 
     +-	if (!tr2env_normal_brief) {
     ++	if (!tr2env_normal_be_brief) {
     + 		struct tr2_tbuf tb_now;
     + 
     + 		tr2_tbuf_local_time(&tb_now);
      
       diff --git a/trace2/tr2_tgt_perf.c b/trace2/tr2_tgt_perf.c
       --- a/trace2/tr2_tgt_perf.c
     @@ -772,9 +857,11 @@
        * Unit tests may want to use this to help with testing.
        */
      -#define TR2_ENVVAR_PERF_BRIEF "GIT_TR2_PERF_BRIEF"
     - static int tr2env_perf_brief;
     +-static int tr2env_perf_brief;
     ++static int tr2env_perf_be_brief;
       
       #define TR2FMT_PERF_FL_WIDTH (50)
     + #define TR2FMT_PERF_MAX_EVENT_NAME (12)
      @@
       {
       	int want = tr2_dst_trace_want(&tr2dst_perf);
     @@ -791,4 +878,17 @@
      +	brief = tr2_sysenv_get(TR2_SYSENV_PERF_BRIEF);
       	if (brief && *brief &&
       	    ((want_brief = git_parse_maybe_bool(brief)) != -1))
     - 		tr2env_perf_brief = want_brief;
     +-		tr2env_perf_brief = want_brief;
     ++		tr2env_perf_be_brief = want_brief;
     + 
     + 	return want;
     + }
     +@@
     + 
     + 	strbuf_setlen(buf, 0);
     + 
     +-	if (!tr2env_perf_brief) {
     ++	if (!tr2env_perf_be_brief) {
     + 		struct tr2_tbuf tb_now;
     + 
     + 		tr2_tbuf_local_time(&tb_now);
 -:  ---------- > 5:  86d8fe28cf trace2: report peak memory usage of the process
 -:  ---------- > 6:  ae11cc4186 trace2: clarify UTC datetime formatting
 -:  ---------- > 7:  4352952677 trace2: make SIDs more unique

-- 
gitgitgadget

^ permalink raw reply	[flat|nested] 68+ messages in thread

* [PATCH v2 1/7] trace2: refactor setting process starting time
  2019-03-29 17:04 ` [PATCH v2 0/7] trace2: load trace2 settings from system config Jeff Hostetler via GitGitGadget
@ 2019-03-29 17:04   ` Jeff Hostetler via GitGitGadget
  2019-03-29 17:04   ` [PATCH v2 2/7] trace2: add absolute elapsed time to start event Jeff Hostetler via GitGitGadget
                     ` (7 subsequent siblings)
  8 siblings, 0 replies; 68+ messages in thread
From: Jeff Hostetler via GitGitGadget @ 2019-03-29 17:04 UTC (permalink / raw)
  To: git
  Cc: gitster, peff, jrnieder, steadmon, avarab, Junio C Hamano,
	Jeff Hostetler

From: Jeff Hostetler <jeffhost@microsoft.com>

Create trace2_initialize_clock() and call from main() to capture
process start time in isolation and before other sub-systems are
ready.

Signed-off-by: Jeff Hostetler <jeffhost@microsoft.com>
---
 Documentation/technical/api-trace2.txt | 12 ++++++--
 common-main.c                          |  2 ++
 compat/mingw.c                         |  2 ++
 trace2.c                               |  7 ++++-
 trace2.h                               | 17 ++++++++++++
 trace2/tr2_tls.c                       | 38 ++++++++++++++++----------
 trace2/tr2_tls.h                       |  8 +++++-
 7 files changed, 67 insertions(+), 19 deletions(-)

diff --git a/Documentation/technical/api-trace2.txt b/Documentation/technical/api-trace2.txt
index 2de565fa3d..f37fccf1da 100644
--- a/Documentation/technical/api-trace2.txt
+++ b/Documentation/technical/api-trace2.txt
@@ -160,17 +160,23 @@ purposes.
 
 These are concerned with the lifetime of the overall git process.
 
+`void trace2_initialize_clock()`::
+
+	Initialize the Trace2 start clock and nothing else.  This should
+	be called at the very top of main() to capture the process start
+	time and reduce startup order dependencies.
+
 `void trace2_initialize()`::
 
 	Determines if any Trace2 Targets should be enabled and
-	initializes the Trace2 facility.  This includes starting the
-	elapsed time clocks and thread local storage (TLS).
+	initializes the Trace2 facility.  This includes setting up the
+	Trace2 thread local storage (TLS).
 +
 This function emits a "version" message containing the version of git
 and the Trace2 protocol.
 +
 This function should be called from `main()` as early as possible in
-the life of the process.
+the life of the process after essential process initialization.
 
 `int trace2_is_enabled()`::
 
diff --git a/common-main.c b/common-main.c
index d484aec209..6137af0e63 100644
--- a/common-main.c
+++ b/common-main.c
@@ -27,6 +27,8 @@ int main(int argc, const char **argv)
 {
 	int result;
 
+	trace2_initialize_clock();
+
 	/*
 	 * Always open file descriptors 0/1/2 to avoid clobbering files
 	 * in die().  It also avoids messing up when the pipes are dup'ed
diff --git a/compat/mingw.c b/compat/mingw.c
index 6b04514cdc..a2f74aca6a 100644
--- a/compat/mingw.c
+++ b/compat/mingw.c
@@ -2569,6 +2569,8 @@ void mingw_startup(void)
 	wchar_t **wenv, **wargv;
 	_startupinfo si;
 
+	trace2_initialize_clock();
+
 	maybe_redirect_std_handles();
 
 	/* get wide char arguments and environment */
diff --git a/trace2.c b/trace2.c
index ccccd4ef09..6dd51e6aa5 100644
--- a/trace2.c
+++ b/trace2.c
@@ -142,6 +142,11 @@ static void tr2main_signal_handler(int signo)
 	raise(signo);
 }
 
+void trace2_initialize_clock(void)
+{
+	tr2tls_start_process_clock();
+}
+
 void trace2_initialize_fl(const char *file, int line)
 {
 	struct tr2_tgt *tgt_j;
@@ -428,7 +433,7 @@ void trace2_thread_start_fl(const char *file, int line, const char *thread_name)
 	us_now = getnanotime() / 1000;
 	us_elapsed_absolute = tr2tls_absolute_elapsed(us_now);
 
-	tr2tls_create_self(thread_name);
+	tr2tls_create_self(thread_name, us_now);
 
 	for_each_wanted_builtin (j, tgt_j)
 		if (tgt_j->pfn_thread_start_fl)
diff --git a/trace2.h b/trace2.h
index ae5020d0e6..8f89e70c44 100644
--- a/trace2.h
+++ b/trace2.h
@@ -19,6 +19,23 @@ struct json_writer;
  * [] trace2_printf*    -- legacy trace[1] messages.
  */
 
+/*
+ * Initialize the TRACE2 clock and do nothing else, in particular
+ * no mallocs, no system inspection, and no environment inspection.
+ *
+ * This should be called at the very top of main() to capture the
+ * process start time.  This is intended to reduce chicken-n-egg
+ * bootstrap pressure.
+ *
+ * It is safe to call this more than once.  This allows capturing
+ * absolute startup costs on Windows which uses a little trickery
+ * to do setup work before common-main.c:main() is called.
+ *
+ * The main trace2_initialize_fl() may be called a little later
+ * after more infrastructure is established.
+ */
+void trace2_initialize_clock(void);
+
 /*
  * Initialize TRACE2 tracing facility if any of the builtin TRACE2
  * targets are enabled in the environment.  Emits a 'version' event.
diff --git a/trace2/tr2_tls.c b/trace2/tr2_tls.c
index 8e65b0361d..31fb529f93 100644
--- a/trace2/tr2_tls.c
+++ b/trace2/tr2_tls.c
@@ -10,16 +10,30 @@
 #define TR2_REGION_NESTING_INITIAL_SIZE (100)
 
 static struct tr2tls_thread_ctx *tr2tls_thread_main;
-static uint64_t tr2tls_us_start_main;
+static uint64_t tr2tls_us_start_process;
 
 static pthread_mutex_t tr2tls_mutex;
 static pthread_key_t tr2tls_key;
 
 static int tr2_next_thread_id; /* modify under lock */
 
-struct tr2tls_thread_ctx *tr2tls_create_self(const char *thread_name)
+void tr2tls_start_process_clock(void)
+{
+	if (tr2tls_us_start_process)
+		return;
+
+	/*
+	 * Keep the absolute start time of the process (i.e. the main
+	 * process) in a fixed variable since other threads need to
+	 * access it.  This allows them to do that without a lock on
+	 * main thread's array data (because of reallocs).
+	 */
+	tr2tls_us_start_process = getnanotime() / 1000;
+}
+
+struct tr2tls_thread_ctx *tr2tls_create_self(const char *thread_name,
+					     uint64_t us_thread_start)
 {
-	uint64_t us_now = getnanotime() / 1000;
 	struct tr2tls_thread_ctx *ctx = xcalloc(1, sizeof(*ctx));
 
 	/*
@@ -29,7 +43,7 @@ struct tr2tls_thread_ctx *tr2tls_create_self(const char *thread_name)
 	 */
 	ctx->alloc = TR2_REGION_NESTING_INITIAL_SIZE;
 	ctx->array_us_start = (uint64_t *)xcalloc(ctx->alloc, sizeof(uint64_t));
-	ctx->array_us_start[ctx->nr_open_regions++] = us_now;
+	ctx->array_us_start[ctx->nr_open_regions++] = us_thread_start;
 
 	ctx->thread_id = tr2tls_locked_increment(&tr2_next_thread_id);
 
@@ -55,7 +69,7 @@ struct tr2tls_thread_ctx *tr2tls_get_self(void)
 	 * here and silently continue.
 	 */
 	if (!ctx)
-		ctx = tr2tls_create_self("unknown");
+		ctx = tr2tls_create_self("unknown", getnanotime() / 1000);
 
 	return ctx;
 }
@@ -124,22 +138,18 @@ uint64_t tr2tls_absolute_elapsed(uint64_t us)
 	if (!tr2tls_thread_main)
 		return 0;
 
-	return us - tr2tls_us_start_main;
+	return us - tr2tls_us_start_process;
 }
 
 void tr2tls_init(void)
 {
+	tr2tls_start_process_clock();
+
 	pthread_key_create(&tr2tls_key, NULL);
 	init_recursive_mutex(&tr2tls_mutex);
 
-	tr2tls_thread_main = tr2tls_create_self("main");
-	/*
-	 * Keep a copy of the absolute start time of the main thread
-	 * in a fixed variable since other threads need to access it.
-	 * This also eliminates the need to lock accesses to the main
-	 * thread's array (because of reallocs).
-	 */
-	tr2tls_us_start_main = tr2tls_thread_main->array_us_start[0];
+	tr2tls_thread_main = tr2tls_create_self("main",
+						tr2tls_us_start_process);
 }
 
 void tr2tls_release(void)
diff --git a/trace2/tr2_tls.h b/trace2/tr2_tls.h
index bb80e3f8e7..b1e327a928 100644
--- a/trace2/tr2_tls.h
+++ b/trace2/tr2_tls.h
@@ -31,7 +31,8 @@ struct tr2tls_thread_ctx {
  * In this and all following functions the term "self" refers to the
  * current thread.
  */
-struct tr2tls_thread_ctx *tr2tls_create_self(const char *thread_name);
+struct tr2tls_thread_ctx *tr2tls_create_self(const char *thread_name,
+					     uint64_t us_thread_start);
 
 /*
  * Get our TLS data.
@@ -94,4 +95,9 @@ void tr2tls_release(void);
  */
 int tr2tls_locked_increment(int *p);
 
+/*
+ * Capture the process start time and do nothing else.
+ */
+void tr2tls_start_process_clock(void);
+
 #endif /* TR2_TLS_H */
-- 
gitgitgadget


^ permalink raw reply	[flat|nested] 68+ messages in thread

* [PATCH v2 2/7] trace2: add absolute elapsed time to start event
  2019-03-29 17:04 ` [PATCH v2 0/7] trace2: load trace2 settings from system config Jeff Hostetler via GitGitGadget
  2019-03-29 17:04   ` [PATCH v2 1/7] trace2: refactor setting process starting time Jeff Hostetler via GitGitGadget
@ 2019-03-29 17:04   ` Jeff Hostetler via GitGitGadget
  2019-03-29 17:04   ` [PATCH v2 3/7] trace2: find exec-dir before trace2 initialization Jeff Hostetler via GitGitGadget
                     ` (6 subsequent siblings)
  8 siblings, 0 replies; 68+ messages in thread
From: Jeff Hostetler via GitGitGadget @ 2019-03-29 17:04 UTC (permalink / raw)
  To: git
  Cc: gitster, peff, jrnieder, steadmon, avarab, Junio C Hamano,
	Jeff Hostetler

From: Jeff Hostetler <jeffhost@microsoft.com>

Add elapsed process time to "start" event to measure
the performance of early process startup.

Signed-off-by: Jeff Hostetler <jeffhost@microsoft.com>
---
 Documentation/technical/api-trace2.txt | 11 ++++++-----
 t/t0211-trace2-perf.sh                 | 12 ++++++------
 trace2.c                               |  8 +++++++-
 trace2/tr2_tgt.h                       |  1 +
 trace2/tr2_tgt_event.c                 |  5 ++++-
 trace2/tr2_tgt_normal.c                |  3 ++-
 trace2/tr2_tgt_perf.c                  |  7 ++++---
 7 files changed, 30 insertions(+), 17 deletions(-)

diff --git a/Documentation/technical/api-trace2.txt b/Documentation/technical/api-trace2.txt
index f37fccf1da..baaa1153bb 100644
--- a/Documentation/technical/api-trace2.txt
+++ b/Documentation/technical/api-trace2.txt
@@ -60,7 +60,7 @@ git version 2.20.1.155.g426c96fcdb
 ------------
 $ cat ~/log.perf
 12:28:42.620675 common-main.c:38                  | d0 | main                     | version      |     |           |           |            | 2.20.1.155.g426c96fcdb
-12:28:42.621001 common-main.c:39                  | d0 | main                     | start        |     |           |           |            | git version
+12:28:42.621001 common-main.c:39                  | d0 | main                     | start        |     |  0.001173 |           |            | git version
 12:28:42.621111 git.c:432                         | d0 | main                     | cmd_name     |     |           |           |            | version (version)
 12:28:42.621225 git.c:662                         | d0 | main                     | exit         |     |  0.001227 |           |            | code:0
 12:28:42.621259 trace2/tr2_tgt_perf.c:211         | d0 | main                     | atexit       |     |  0.001265 |           |            | code:0
@@ -79,7 +79,7 @@ git version 2.20.1.155.g426c96fcdb
 ------------
 $ cat ~/log.event
 {"event":"version","sid":"1547659722619736-11614","thread":"main","time":"2019-01-16 17:28:42.620713","file":"common-main.c","line":38,"evt":"1","exe":"2.20.1.155.g426c96fcdb"}
-{"event":"start","sid":"1547659722619736-11614","thread":"main","time":"2019-01-16 17:28:42.621027","file":"common-main.c","line":39,"argv":["git","version"]}
+{"event":"start","sid":"1547659722619736-11614","thread":"main","time":"2019-01-16 17:28:42.621027","file":"common-main.c","line":39,"t_abs":0.001173,"argv":["git","version"]}
 {"event":"cmd_name","sid":"1547659722619736-11614","thread":"main","time":"2019-01-16 17:28:42.621122","file":"git.c","line":432,"name":"version","hierarchy":"version"}
 {"event":"exit","sid":"1547659722619736-11614","thread":"main","time":"2019-01-16 17:28:42.621236","file":"git.c","line":662,"t_abs":0.001227,"code":0}
 {"event":"atexit","sid":"1547659722619736-11614","thread":"main","time":"2019-01-16 17:28:42.621268","file":"trace2/tr2_tgt_event.c","line":163,"t_abs":0.001265,"code":0}
@@ -601,6 +601,7 @@ from all events and the `time` field is only present on the "start" and
 {
 	"event":"start",
 	...
+	"t_abs":0.001227, # elapsed time in seconds
 	"argv":["git","version"]
 }
 ------------
@@ -1118,7 +1119,7 @@ $ git status
 
 $ cat ~/log.perf
 d0 | main                     | version      |     |           |           |            | 2.20.1.160.g5676107ecd.dirty
-d0 | main                     | start        |     |           |           |            | git status
+d0 | main                     | start        |     |  0.001173 |           |            | git status
 d0 | main                     | def_repo     | r1  |           |           |            | worktree:/Users/jeffhost/work/gfw
 d0 | main                     | cmd_name     |     |           |           |            | status (status)
 ...
@@ -1163,7 +1164,7 @@ $ git status
 ...
 $ cat ~/log.perf
 d0 | main                     | version      |     |           |           |            | 2.20.1.162.gb4ccea44db.dirty
-d0 | main                     | start        |     |           |           |            | git status
+d0 | main                     | start        |     |  0.001173 |           |            | git status
 d0 | main                     | def_repo     | r1  |           |           |            | worktree:/Users/jeffhost/work/gfw
 d0 | main                     | cmd_name     |     |           |           |            | status (status)
 ...
@@ -1219,7 +1220,7 @@ $ git status
 ...
 $ cat ~/log.perf
 d0 | main                     | version      |     |           |           |            | 2.20.1.156.gf9916ae094.dirty
-d0 | main                     | start        |     |           |           |            | git status
+d0 | main                     | start        |     |  0.001173 |           |            | git status
 d0 | main                     | def_repo     | r1  |           |           |            | worktree:/Users/jeffhost/work/gfw
 d0 | main                     | cmd_name     |     |           |           |            | status (status)
 d0 | main                     | region_enter | r1  |  0.001791 |           | index      | label:do_read_index .git/index
diff --git a/t/t0211-trace2-perf.sh b/t/t0211-trace2-perf.sh
index 953e2f7847..c9694b29f7 100755
--- a/t/t0211-trace2-perf.sh
+++ b/t/t0211-trace2-perf.sh
@@ -50,7 +50,7 @@ test_expect_success 'perf stream, return code 0' '
 	perl "$TEST_DIRECTORY/t0211/scrub_perf.perl" <trace.perf >actual &&
 	cat >expect <<-EOF &&
 		d0|main|version|||||$V
-		d0|main|start|||||_EXE_ trace2 001return 0
+		d0|main|start||_T_ABS_|||_EXE_ trace2 001return 0
 		d0|main|cmd_name|||||trace2 (trace2)
 		d0|main|exit||_T_ABS_|||code:0
 		d0|main|atexit||_T_ABS_|||code:0
@@ -64,7 +64,7 @@ test_expect_success 'perf stream, return code 1' '
 	perl "$TEST_DIRECTORY/t0211/scrub_perf.perl" <trace.perf >actual &&
 	cat >expect <<-EOF &&
 		d0|main|version|||||$V
-		d0|main|start|||||_EXE_ trace2 001return 1
+		d0|main|start||_T_ABS_|||_EXE_ trace2 001return 1
 		d0|main|cmd_name|||||trace2 (trace2)
 		d0|main|exit||_T_ABS_|||code:1
 		d0|main|atexit||_T_ABS_|||code:1
@@ -82,7 +82,7 @@ test_expect_success 'perf stream, error event' '
 	perl "$TEST_DIRECTORY/t0211/scrub_perf.perl" <trace.perf >actual &&
 	cat >expect <<-EOF &&
 		d0|main|version|||||$V
-		d0|main|start|||||_EXE_ trace2 003error '\''hello world'\'' '\''this is a test'\''
+		d0|main|start||_T_ABS_|||_EXE_ trace2 003error '\''hello world'\'' '\''this is a test'\''
 		d0|main|cmd_name|||||trace2 (trace2)
 		d0|main|error|||||hello world
 		d0|main|error|||||this is a test
@@ -128,15 +128,15 @@ test_expect_success 'perf stream, child processes' '
 	perl "$TEST_DIRECTORY/t0211/scrub_perf.perl" <trace.perf >actual &&
 	cat >expect <<-EOF &&
 		d0|main|version|||||$V
-		d0|main|start|||||_EXE_ trace2 004child test-tool trace2 004child test-tool trace2 001return 0
+		d0|main|start||_T_ABS_|||_EXE_ trace2 004child test-tool trace2 004child test-tool trace2 001return 0
 		d0|main|cmd_name|||||trace2 (trace2)
 		d0|main|child_start||_T_ABS_|||[ch0] class:? argv: test-tool trace2 004child test-tool trace2 001return 0
 		d1|main|version|||||$V
-		d1|main|start|||||_EXE_ trace2 004child test-tool trace2 001return 0
+		d1|main|start||_T_ABS_|||_EXE_ trace2 004child test-tool trace2 001return 0
 		d1|main|cmd_name|||||trace2 (trace2/trace2)
 		d1|main|child_start||_T_ABS_|||[ch0] class:? argv: test-tool trace2 001return 0
 		d2|main|version|||||$V
-		d2|main|start|||||_EXE_ trace2 001return 0
+		d2|main|start||_T_ABS_|||_EXE_ trace2 001return 0
 		d2|main|cmd_name|||||trace2 (trace2/trace2/trace2)
 		d2|main|exit||_T_ABS_|||code:0
 		d2|main|atexit||_T_ABS_|||code:0
diff --git a/trace2.c b/trace2.c
index 6dd51e6aa5..1c180062dd 100644
--- a/trace2.c
+++ b/trace2.c
@@ -182,13 +182,19 @@ void trace2_cmd_start_fl(const char *file, int line, const char **argv)
 {
 	struct tr2_tgt *tgt_j;
 	int j;
+	uint64_t us_now;
+	uint64_t us_elapsed_absolute;
 
 	if (!trace2_enabled)
 		return;
 
+	us_now = getnanotime() / 1000;
+	us_elapsed_absolute = tr2tls_absolute_elapsed(us_now);
+
 	for_each_wanted_builtin (j, tgt_j)
 		if (tgt_j->pfn_start_fl)
-			tgt_j->pfn_start_fl(file, line, argv);
+			tgt_j->pfn_start_fl(file, line, us_elapsed_absolute,
+					    argv);
 }
 
 int trace2_cmd_exit_fl(const char *file, int line, int code)
diff --git a/trace2/tr2_tgt.h b/trace2/tr2_tgt.h
index 297bb8ffbe..7b90469212 100644
--- a/trace2/tr2_tgt.h
+++ b/trace2/tr2_tgt.h
@@ -15,6 +15,7 @@ typedef void(tr2_tgt_term_t)(void);
 typedef void(tr2_tgt_evt_version_fl_t)(const char *file, int line);
 
 typedef void(tr2_tgt_evt_start_fl_t)(const char *file, int line,
+				     uint64_t us_elapsed_absolute,
 				     const char **argv);
 typedef void(tr2_tgt_evt_exit_fl_t)(const char *file, int line,
 				    uint64_t us_elapsed_absolute, int code);
diff --git a/trace2/tr2_tgt_event.c b/trace2/tr2_tgt_event.c
index 107cb5317d..89a4d3ae9a 100644
--- a/trace2/tr2_tgt_event.c
+++ b/trace2/tr2_tgt_event.c
@@ -122,13 +122,16 @@ static void fn_version_fl(const char *file, int line)
 	jw_release(&jw);
 }
 
-static void fn_start_fl(const char *file, int line, const char **argv)
+static void fn_start_fl(const char *file, int line,
+			uint64_t us_elapsed_absolute, const char **argv)
 {
 	const char *event_name = "start";
 	struct json_writer jw = JSON_WRITER_INIT;
+	double t_abs = (double)us_elapsed_absolute / 1000000.0;
 
 	jw_object_begin(&jw, 0);
 	event_fmt_prepare(event_name, file, line, NULL, &jw);
+	jw_object_double(&jw, "t_abs", 6, t_abs);
 	jw_object_inline_begin_array(&jw, "argv");
 	jw_array_argv(&jw, argv);
 	jw_end(&jw);
diff --git a/trace2/tr2_tgt_normal.c b/trace2/tr2_tgt_normal.c
index 547183d5b6..57f3e18f5b 100644
--- a/trace2/tr2_tgt_normal.c
+++ b/trace2/tr2_tgt_normal.c
@@ -81,7 +81,8 @@ static void fn_version_fl(const char *file, int line)
 	strbuf_release(&buf_payload);
 }
 
-static void fn_start_fl(const char *file, int line, const char **argv)
+static void fn_start_fl(const char *file, int line,
+			uint64_t us_elapsed_absolute, const char **argv)
 {
 	struct strbuf buf_payload = STRBUF_INIT;
 
diff --git a/trace2/tr2_tgt_perf.c b/trace2/tr2_tgt_perf.c
index f0746fcf86..9c3b4d8a0f 100644
--- a/trace2/tr2_tgt_perf.c
+++ b/trace2/tr2_tgt_perf.c
@@ -159,15 +159,16 @@ static void fn_version_fl(const char *file, int line)
 	strbuf_release(&buf_payload);
 }
 
-static void fn_start_fl(const char *file, int line, const char **argv)
+static void fn_start_fl(const char *file, int line,
+			uint64_t us_elapsed_absolute, const char **argv)
 {
 	const char *event_name = "start";
 	struct strbuf buf_payload = STRBUF_INIT;
 
 	sq_quote_argv_pretty(&buf_payload, argv);
 
-	perf_io_write_fl(file, line, event_name, NULL, NULL, NULL, NULL,
-			 &buf_payload);
+	perf_io_write_fl(file, line, event_name, NULL, &us_elapsed_absolute,
+			 NULL, NULL, &buf_payload);
 	strbuf_release(&buf_payload);
 }
 
-- 
gitgitgadget


^ permalink raw reply	[flat|nested] 68+ messages in thread

* [PATCH v2 3/7] trace2: find exec-dir before trace2 initialization
  2019-03-29 17:04 ` [PATCH v2 0/7] trace2: load trace2 settings from system config Jeff Hostetler via GitGitGadget
  2019-03-29 17:04   ` [PATCH v2 1/7] trace2: refactor setting process starting time Jeff Hostetler via GitGitGadget
  2019-03-29 17:04   ` [PATCH v2 2/7] trace2: add absolute elapsed time to start event Jeff Hostetler via GitGitGadget
@ 2019-03-29 17:04   ` Jeff Hostetler via GitGitGadget
  2019-03-29 17:04   ` [PATCH v2 4/7] trace2: use system config for default trace2 settings Jeff Hostetler via GitGitGadget
                     ` (5 subsequent siblings)
  8 siblings, 0 replies; 68+ messages in thread
From: Jeff Hostetler via GitGitGadget @ 2019-03-29 17:04 UTC (permalink / raw)
  To: git
  Cc: gitster, peff, jrnieder, steadmon, avarab, Junio C Hamano,
	Jeff Hostetler

From: Jeff Hostetler <jeffhost@microsoft.com>

Teach Git to resolve the executable directory before initializing
Trace2.  This allows the system configuration directory to be
discovered earlier (because it is sometimes relative to the prefix
or runtime-prefix).

This will be used by the next commit to allow trace2 settings to
be loaded from the system config.

Signed-off-by: Jeff Hostetler <jeffhost@microsoft.com>
---
 common-main.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/common-main.c b/common-main.c
index 6137af0e63..299ca62a72 100644
--- a/common-main.c
+++ b/common-main.c
@@ -37,12 +37,12 @@ int main(int argc, const char **argv)
 	sanitize_stdfds();
 	restore_sigpipe_to_default();
 
+	git_resolve_executable_dir(argv[0]);
+
 	trace2_initialize();
 	trace2_cmd_start(argv);
 	trace2_collect_process_info();
 
-	git_resolve_executable_dir(argv[0]);
-
 	git_setup_gettext();
 
 	initialize_the_repository();
-- 
gitgitgadget


^ permalink raw reply	[flat|nested] 68+ messages in thread

* [PATCH v2 4/7] trace2: use system config for default trace2 settings
  2019-03-29 17:04 ` [PATCH v2 0/7] trace2: load trace2 settings from system config Jeff Hostetler via GitGitGadget
                     ` (2 preceding siblings ...)
  2019-03-29 17:04   ` [PATCH v2 3/7] trace2: find exec-dir before trace2 initialization Jeff Hostetler via GitGitGadget
@ 2019-03-29 17:04   ` Jeff Hostetler via GitGitGadget
  2019-04-01 21:00     ` Josh Steadmon
  2019-04-03  0:00     ` Jonathan Nieder
  2019-03-29 17:04   ` [PATCH v2 5/7] trace2: report peak memory usage of the process Jeff Hostetler via GitGitGadget
                     ` (4 subsequent siblings)
  8 siblings, 2 replies; 68+ messages in thread
From: Jeff Hostetler via GitGitGadget @ 2019-03-29 17:04 UTC (permalink / raw)
  To: git
  Cc: gitster, peff, jrnieder, steadmon, avarab, Junio C Hamano,
	Jeff Hostetler

From: Jeff Hostetler <jeffhost@microsoft.com>

Teach git to read the system config (usually "/etc/gitconfig") for
default Trace2 settings.  This allows system-wide Trace2 settings to
be installed and inherited to make it easier to manage a collection of
systems.

The original GIT_TR2* environment variables are loaded afterwards and
can be used to override the system settings.

Only the system config file is used.  Trace2 config values are ignored
in local, global, and other config files.  Likewise, the "-c" command
line arguments are ignored for Trace2 values.  These limits are for
performance reasons.

(1) For users not using Trace2, there should be minimal overhead to
detect that Trace2 is not enabled.  In particular, Trace2 should not
allocate lots of otherwise unused data strucutres.

(2) For accurate performance measurements, Trace2 should be initialized
as early in the git process as possible, and before most of the normal
git process initialization (which involves discovering the .git directory
and reading a hierarchy of config files).

Added the GIT_TEST_TR2_SYSTEM_CONFIG environment variable for testing
purposes to specify the pathname of a fake "system" config or disable
use of the system config.

Signed-off-by: Jeff Hostetler <jeffhost@microsoft.com>
---
 Documentation/technical/api-trace2.txt |  31 ++++++
 Makefile                               |   1 +
 t/t0210-trace2-normal.sh               |  41 +++++++-
 t/t0211-trace2-perf.sh                 |  41 +++++++-
 t/t0212-trace2-event.sh                |  52 +++++++++-
 trace2.c                               |   4 +
 trace2.h                               |  12 ++-
 trace2/tr2_cfg.c                       |   7 +-
 trace2/tr2_dst.c                       |  24 ++---
 trace2/tr2_dst.h                       |   3 +-
 trace2/tr2_sysenv.c                    | 128 +++++++++++++++++++++++++
 trace2/tr2_sysenv.h                    |  36 +++++++
 trace2/tr2_tgt_event.c                 |  46 ++++-----
 trace2/tr2_tgt_normal.c                |  16 ++--
 trace2/tr2_tgt_perf.c                  |  16 ++--
 15 files changed, 382 insertions(+), 76 deletions(-)
 create mode 100644 trace2/tr2_sysenv.c
 create mode 100644 trace2/tr2_sysenv.h

diff --git a/Documentation/technical/api-trace2.txt b/Documentation/technical/api-trace2.txt
index baaa1153bb..13ca595c69 100644
--- a/Documentation/technical/api-trace2.txt
+++ b/Documentation/technical/api-trace2.txt
@@ -117,6 +117,37 @@ values are recognized.
 Socket type can be either `stream` or `dgram`.  If the socket type is
 omitted, Git will try both.
 
+== Trace2 Settings in System Config
+
+Trace2 also reads configuration information from the system config.
+This is intended to help adminstrators to gather system-wide Git
+performance data.
+
+Trace2 only reads the system configuration, it does not read global,
+local, worktree, or `-c` config settings.
+
+Trace2 will try to load the following system configuration settings
+and then read the corresponding environment variables at startup.
+
+....
+---------------------------------------------------
+trace2.normalTarget          GIT_TR2
+trace2.normalBrief           GIT_TR2_BRIEF
+
+trace2.perfTarget            GIT_TR2_PERF
+trace2.perfBrief             GIT_TR2_PERF_BRIEF
+
+trace2.eventTarget           GIT_TR2_EVENT
+trace2.eventBrief            GIT_TR2_EVENT_BRIEF
+trace2.eventNesting          GIT_TR2_EVENT_NESTING
+
+trace2.configParams          GIT_TR2_CONFIG_PARAMS
+
+trace2.destinationDebug      GIT_TR2_DST_DEBUG
+---------------------------------------------------
+....
+
+
 == Trace2 API
 
 All public Trace2 functions and macros are defined in `trace2.h` and
diff --git a/Makefile b/Makefile
index 3e03290d8f..9ddfa3dfe7 100644
--- a/Makefile
+++ b/Makefile
@@ -1005,6 +1005,7 @@ LIB_OBJS += trace2/tr2_cfg.o
 LIB_OBJS += trace2/tr2_cmd_name.o
 LIB_OBJS += trace2/tr2_dst.o
 LIB_OBJS += trace2/tr2_sid.o
+LIB_OBJS += trace2/tr2_sysenv.o
 LIB_OBJS += trace2/tr2_tbuf.o
 LIB_OBJS += trace2/tr2_tgt_event.o
 LIB_OBJS += trace2/tr2_tgt_normal.o
diff --git a/t/t0210-trace2-normal.sh b/t/t0210-trace2-normal.sh
index 03a0aedb1d..5d4c04ed30 100755
--- a/t/t0210-trace2-normal.sh
+++ b/t/t0210-trace2-normal.sh
@@ -1,5 +1,14 @@
 #!/bin/sh
 
+# Disable loading of Trace2 settings from the system config
+# (usually "/etc/gitconfig") to eliminate system dependencies.
+GIT_TEST_TR2_SYSTEM_CONFIG=0 && export GIT_TEST_TR2_SYSTEM_CONFIG
+
+# Turn off any inherited trace2 settings for this test.
+unset GIT_TR2 GIT_TR2_PERF GIT_TR2_EVENT
+unset GIT_TR2_BRIEF
+unset GIT_TR2_CONFIG_PARAMS
+
 test_description='test trace2 facility (normal target)'
 . ./test-lib.sh
 
@@ -15,11 +24,6 @@ PATH="$TTDIR:$PATH" && export PATH
 # Warning: So you may see extra lines in artifact files when
 # Warning: interactively debugging.
 
-# Turn off any inherited trace2 settings for this test.
-unset GIT_TR2 GIT_TR2_PERF GIT_TR2_EVENT
-unset GIT_TR2_BRIEF
-unset GIT_TR2_CONFIG_PARAMS
-
 V=$(git version | sed -e 's/^git version //') && export V
 
 # There are multiple trace2 targets: normal, perf, and event.
@@ -132,4 +136,31 @@ test_expect_success 'normal stream, error event' '
 	test_cmp expect actual
 '
 
+# Now test using system config by using a mocked up config file
+# rather than inheriting "/etc/gitconfig".  Here we do not use
+# GIT_TR2* environment variables.
+
+unset GIT_TR2_BRIEF
+
+MOCK=./mock_system_config
+
+test_expect_success 'setup mocked /etc/gitconfig' '
+	git config --file $MOCK trace2.normalTarget "$(pwd)/trace.normal" &&
+	git config --file $MOCK trace2.normalBrief 1
+'
+
+test_expect_success 'using mock, normal stream, return code 0' '
+	test_when_finished "rm trace.normal actual expect" &&
+	GIT_TEST_TR2_SYSTEM_CONFIG="$MOCK" test-tool trace2 001return 0 &&
+	perl "$TEST_DIRECTORY/t0210/scrub_normal.perl" <trace.normal >actual &&
+	cat >expect <<-EOF &&
+		version $V
+		start _EXE_ trace2 001return 0
+		cmd_name trace2 (trace2)
+		exit elapsed:_TIME_ code:0
+		atexit elapsed:_TIME_ code:0
+	EOF
+	test_cmp expect actual
+'
+
 test_done
diff --git a/t/t0211-trace2-perf.sh b/t/t0211-trace2-perf.sh
index c9694b29f7..abe35b2186 100755
--- a/t/t0211-trace2-perf.sh
+++ b/t/t0211-trace2-perf.sh
@@ -1,5 +1,14 @@
 #!/bin/sh
 
+# Disable loading of Trace2 settings from the system config
+# (usually "/etc/gitconfig") to eliminate system dependencies.
+GIT_TEST_TR2_SYSTEM_CONFIG=0 && export GIT_TEST_TR2_SYSTEM_CONFIG
+
+# Turn off any inherited trace2 settings for this test.
+unset GIT_TR2 GIT_TR2_PERF GIT_TR2_EVENT
+unset GIT_TR2_PERF_BRIEF
+unset GIT_TR2_CONFIG_PARAMS
+
 test_description='test trace2 facility (perf target)'
 . ./test-lib.sh
 
@@ -15,11 +24,6 @@ PATH="$TTDIR:$PATH" && export PATH
 # Warning: So you may see extra lines in artifact files when
 # Warning: interactively debugging.
 
-# Turn off any inherited trace2 settings for this test.
-unset GIT_TR2 GIT_TR2_PERF GIT_TR2_EVENT
-unset GIT_TR2_PERF_BRIEF
-unset GIT_TR2_CONFIG_PARAMS
-
 V=$(git version | sed -e 's/^git version //') && export V
 
 # There are multiple trace2 targets: normal, perf, and event.
@@ -150,4 +154,31 @@ test_expect_success 'perf stream, child processes' '
 	test_cmp expect actual
 '
 
+# Now test using system config by using a mocked up config file
+# rather than inheriting "/etc/gitconfig".  Here we do not use
+# GIT_TR2* environment variables.
+
+unset GIT_TR2_PERF_BRIEF
+
+MOCK=./mock_system_config
+
+test_expect_success 'setup mocked /etc/gitconfig' '
+	git config --file $MOCK trace2.perfTarget "$(pwd)/trace.perf" &&
+	git config --file $MOCK trace2.perfBrief 1
+'
+
+test_expect_success 'using mock, perf stream, return code 0' '
+	test_when_finished "rm trace.perf actual expect" &&
+	GIT_TEST_TR2_SYSTEM_CONFIG="$MOCK" test-tool trace2 001return 0 &&
+	perl "$TEST_DIRECTORY/t0211/scrub_perf.perl" <trace.perf >actual &&
+	cat >expect <<-EOF &&
+		d0|main|version|||||$V
+		d0|main|start||_T_ABS_|||_EXE_ trace2 001return 0
+		d0|main|cmd_name|||||trace2 (trace2)
+		d0|main|exit||_T_ABS_|||code:0
+		d0|main|atexit||_T_ABS_|||code:0
+	EOF
+	test_cmp expect actual
+'
+
 test_done
diff --git a/t/t0212-trace2-event.sh b/t/t0212-trace2-event.sh
index 028b6c5671..c535496261 100755
--- a/t/t0212-trace2-event.sh
+++ b/t/t0212-trace2-event.sh
@@ -1,5 +1,14 @@
 #!/bin/sh
 
+# Disable loading of Trace2 settings from the system config
+# (usually "/etc/gitconfig") to eliminate system dependencies.
+GIT_TEST_TR2_SYSTEM_CONFIG=0 && export GIT_TEST_TR2_SYSTEM_CONFIG
+
+# Turn off any inherited trace2 settings for this test.
+unset GIT_TR2 GIT_TR2_PERF GIT_TR2_EVENT
+unset GIT_TR2_BARE
+unset GIT_TR2_CONFIG_PARAMS
+
 test_description='test trace2 facility'
 . ./test-lib.sh
 
@@ -17,11 +26,6 @@ PATH="$TTDIR:$PATH" && export PATH
 # Warning: So you may see extra lines in artifact files when
 # Warning: interactively debugging.
 
-# Turn off any inherited trace2 settings for this test.
-unset GIT_TR2 GIT_TR2_PERF GIT_TR2_EVENT
-unset GIT_TR2_BARE
-unset GIT_TR2_CONFIG_PARAMS
-
 V=$(git version | sed -e 's/^git version //') && export V
 
 # There are multiple trace2 targets: normal, perf, and event.
@@ -233,4 +237,42 @@ test_expect_success JSON_PP 'basic trace2_data' '
 	test_cmp expect actual
 '
 
+# Now test using system config by using a mocked up config file
+# rather than inheriting "/etc/gitconfig".  Here we do not use
+# GIT_TR2* environment variables.
+
+MOCK=./mock_system_config
+
+test_expect_success 'setup mocked /etc/gitconfig' '
+	git config --file $MOCK trace2.eventTarget "$(pwd)/trace.event"
+'
+
+test_expect_success JSON_PP 'using mock, event stream, error event' '
+	test_when_finished "rm trace.event actual expect" &&
+	GIT_TEST_TR2_SYSTEM_CONFIG="$MOCK" test-tool trace2 003error "hello world" "this is a test" &&
+	perl "$TEST_DIRECTORY/t0212/parse_events.perl" <trace.event >actual &&
+	sed -e "s/^|//" >expect <<-EOF &&
+	|VAR1 = {
+	|  "_SID0_":{
+	|    "argv":[
+	|      "_EXE_",
+	|      "trace2",
+	|      "003error",
+	|      "hello world",
+	|      "this is a test"
+	|    ],
+	|    "errors":[
+	|      "%s",
+	|      "%s"
+	|    ],
+	|    "exit_code":0,
+	|    "hierarchy":"trace2",
+	|    "name":"trace2",
+	|    "version":"$V"
+	|  }
+	|};
+	EOF
+	test_cmp expect actual
+'
+
 test_done
diff --git a/trace2.c b/trace2.c
index 1c180062dd..490b3f071e 100644
--- a/trace2.c
+++ b/trace2.c
@@ -10,6 +10,7 @@
 #include "trace2/tr2_cmd_name.h"
 #include "trace2/tr2_dst.h"
 #include "trace2/tr2_sid.h"
+#include "trace2/tr2_sysenv.h"
 #include "trace2/tr2_tgt.h"
 #include "trace2/tr2_tls.h"
 
@@ -120,6 +121,7 @@ static void tr2main_atexit_handler(void)
 	tr2_sid_release();
 	tr2_cmd_name_release();
 	tr2_cfg_free_patterns();
+	tr2_sysenv_release();
 
 	trace2_enabled = 0;
 }
@@ -155,6 +157,8 @@ void trace2_initialize_fl(const char *file, int line)
 	if (trace2_enabled)
 		return;
 
+	tr2_sysenv_load();
+
 	if (!tr2_tgt_want_builtins())
 		return;
 	trace2_enabled = 1;
diff --git a/trace2.h b/trace2.h
index 8f89e70c44..894bfca7e0 100644
--- a/trace2.h
+++ b/trace2.h
@@ -38,7 +38,8 @@ void trace2_initialize_clock(void);
 
 /*
  * Initialize TRACE2 tracing facility if any of the builtin TRACE2
- * targets are enabled in the environment.  Emits a 'version' event.
+ * targets are enabled in the system config or the environment.
+ * Emits a 'version' event.
  *
  * Cleanup/Termination is handled automatically by a registered
  * atexit() routine.
@@ -125,10 +126,11 @@ void trace2_cmd_alias_fl(const char *file, int line, const char *alias,
  * Emit one or more 'def_param' events for "interesting" configuration
  * settings.
  *
- * The environment variable "GIT_TR2_CONFIG_PARAMS" can be set to a
- * list of patterns considered important.  For example:
- *
- *    GIT_TR2_CONFIG_PARAMS="core.*,remote.*.url"
+ * Use the TR2_SYSENV_CFG_PARAM setting to register a comma-separated
+ * list of patterns configured important.  For example:
+ *     git config --system trace2.configParams 'core.*,remote.*.url'
+ * or:
+ *     GIT_TR2_CONFIG_PARAMS=core.*,remote.*.url"
  *
  * Note: this routine does a read-only iteration on the config data
  * (using read_early_config()), so it must not be called until enough
diff --git a/trace2/tr2_cfg.c b/trace2/tr2_cfg.c
index b329921ac5..caa7f06948 100644
--- a/trace2/tr2_cfg.c
+++ b/trace2/tr2_cfg.c
@@ -1,8 +1,7 @@
 #include "cache.h"
 #include "config.h"
-#include "tr2_cfg.h"
-
-#define TR2_ENVVAR_CFG_PARAM "GIT_TR2_CONFIG_PARAMS"
+#include "trace2/tr2_cfg.h"
+#include "trace2/tr2_sysenv.h"
 
 static struct strbuf **tr2_cfg_patterns;
 static int tr2_cfg_count_patterns;
@@ -21,7 +20,7 @@ static int tr2_cfg_load_patterns(void)
 		return tr2_cfg_count_patterns;
 	tr2_cfg_loaded = 1;
 
-	envvar = getenv(TR2_ENVVAR_CFG_PARAM);
+	envvar = tr2_sysenv_get(TR2_SYSENV_CFG_PARAM);
 	if (!envvar || !*envvar)
 		return tr2_cfg_count_patterns;
 
diff --git a/trace2/tr2_dst.c b/trace2/tr2_dst.c
index fd490a43ad..575cd69aa9 100644
--- a/trace2/tr2_dst.c
+++ b/trace2/tr2_dst.c
@@ -1,5 +1,6 @@
 #include "cache.h"
 #include "trace2/tr2_dst.h"
+#include "trace2/tr2_sysenv.h"
 
 /*
  * If a Trace2 target cannot be opened for writing, we should issue a
@@ -7,17 +8,13 @@
  * or socket and beyond the user's control -- especially since every
  * git command (and sub-command) will print the message.  So we silently
  * eat these warnings and just discard the trace data.
- *
- * Enable the following environment variable to see these warnings.
  */
-#define TR2_ENVVAR_DST_DEBUG "GIT_TR2_DST_DEBUG"
-
 static int tr2_dst_want_warning(void)
 {
 	static int tr2env_dst_debug = -1;
 
 	if (tr2env_dst_debug == -1) {
-		const char *env_value = getenv(TR2_ENVVAR_DST_DEBUG);
+		const char *env_value = tr2_sysenv_get(TR2_SYSENV_DST_DEBUG);
 		if (!env_value || !*env_value)
 			tr2env_dst_debug = 0;
 		else
@@ -42,7 +39,9 @@ static int tr2_dst_try_path(struct tr2_dst *dst, const char *tgt_value)
 	if (fd == -1) {
 		if (tr2_dst_want_warning())
 			warning("trace2: could not open '%s' for '%s' tracing: %s",
-				tgt_value, dst->env_var_name, strerror(errno));
+				tgt_value,
+				tr2_sysenv_display_name(dst->sysenv_var),
+				strerror(errno));
 
 		tr2_dst_trace_disable(dst);
 		return 0;
@@ -116,7 +115,7 @@ static int tr2_dst_try_unix_domain_socket(struct tr2_dst *dst,
 	if (!path || !*path) {
 		if (tr2_dst_want_warning())
 			warning("trace2: invalid AF_UNIX value '%s' for '%s' tracing",
-				tgt_value, dst->env_var_name);
+				tgt_value, tr2_sysenv_display_name(dst->sysenv_var));
 
 		tr2_dst_trace_disable(dst);
 		return 0;
@@ -126,7 +125,7 @@ static int tr2_dst_try_unix_domain_socket(struct tr2_dst *dst,
 	    strlen(path) >= sizeof(((struct sockaddr_un *)0)->sun_path)) {
 		if (tr2_dst_want_warning())
 			warning("trace2: invalid AF_UNIX path '%s' for '%s' tracing",
-				path, dst->env_var_name);
+				path, tr2_sysenv_display_name(dst->sysenv_var));
 
 		tr2_dst_trace_disable(dst);
 		return 0;
@@ -148,7 +147,7 @@ static int tr2_dst_try_unix_domain_socket(struct tr2_dst *dst,
 error:
 	if (tr2_dst_want_warning())
 		warning("trace2: could not connect to socket '%s' for '%s' tracing: %s",
-			path, dst->env_var_name, strerror(e));
+			path, tr2_sysenv_display_name(dst->sysenv_var), strerror(e));
 
 	tr2_dst_trace_disable(dst);
 	return 0;
@@ -168,7 +167,7 @@ static void tr2_dst_malformed_warning(struct tr2_dst *dst,
 	struct strbuf buf = STRBUF_INIT;
 
 	strbuf_addf(&buf, "trace2: unknown value for '%s': '%s'",
-		    dst->env_var_name, tgt_value);
+		    tr2_sysenv_display_name(dst->sysenv_var), tgt_value);
 	warning("%s", buf.buf);
 
 	strbuf_release(&buf);
@@ -184,7 +183,7 @@ int tr2_dst_get_trace_fd(struct tr2_dst *dst)
 
 	dst->initialized = 1;
 
-	tgt_value = getenv(dst->env_var_name);
+	tgt_value = tr2_sysenv_get(dst->sysenv_var);
 
 	if (!tgt_value || !strcmp(tgt_value, "") || !strcmp(tgt_value, "0") ||
 	    !strcasecmp(tgt_value, "false")) {
@@ -246,7 +245,8 @@ void tr2_dst_write_line(struct tr2_dst *dst, struct strbuf *buf_line)
 		return;
 
 	if (tr2_dst_want_warning())
-		warning("unable to write trace to '%s': %s", dst->env_var_name,
+		warning("unable to write trace to '%s': %s",
+			tr2_sysenv_display_name(dst->sysenv_var),
 			strerror(errno));
 	tr2_dst_trace_disable(dst);
 }
diff --git a/trace2/tr2_dst.h b/trace2/tr2_dst.h
index 9a64f05b02..3adf3bac13 100644
--- a/trace2/tr2_dst.h
+++ b/trace2/tr2_dst.h
@@ -2,9 +2,10 @@
 #define TR2_DST_H
 
 struct strbuf;
+#include "trace2/tr2_sysenv.h"
 
 struct tr2_dst {
-	const char *const env_var_name;
+	enum tr2_sysenv_variable sysenv_var;
 	int fd;
 	unsigned int initialized : 1;
 	unsigned int need_close : 1;
diff --git a/trace2/tr2_sysenv.c b/trace2/tr2_sysenv.c
new file mode 100644
index 0000000000..c6909f8b2d
--- /dev/null
+++ b/trace2/tr2_sysenv.c
@@ -0,0 +1,128 @@
+#include "cache.h"
+#include "config.h"
+#include "dir.h"
+#include "tr2_sysenv.h"
+
+/*
+ * Each entry represents a trace2 setting.
+ * See Documentation/technical/api-trace2.txt
+ */
+struct tr2_sysenv_entry {
+	const char *env_var_name;
+	const char *git_config_name;
+
+	char *value;
+	unsigned int getenv_called : 1;
+};
+
+/*
+ * This table must match "enum tr2_sysenv_variable" in tr2_sysenv.h.
+ * These strings are constant and must match the published names as
+ * described in the documentation.
+ *
+ * We do not define entries for the GIT_TR2_PARENT_* environment
+ * variables because they are transient and used to pass information
+ * from parent to child git processes, rather than settings.
+ */
+/* clang-format off */
+static struct tr2_sysenv_entry tr2_sysenv_settings[] = {
+	{ "GIT_TR2_CONFIG_PARAMS",   "trace2.configparams"     },
+
+	{ "GIT_TR2_DST_DEBUG",       "trace2.destinationdebug" },
+
+	{ "GIT_TR2",                 "trace2.normaltarget"     },
+	{ "GIT_TR2_BRIEF",           "trace2.normalbrief"      },
+
+	{ "GIT_TR2_EVENT",           "trace2.eventtarget"      },
+	{ "GIT_TR2_EVENT_BRIEF",     "trace2.eventbrief"       },
+	{ "GIT_TR2_EVENT_NESTING",   "trace2.eventnesting"     },
+
+	{ "GIT_TR2_PERF",            "trace2.perftarget"       },
+	{ "GIT_TR2_PERF_BRIEF",      "trace2.perfbrief"        },
+};
+/* clang-format on */
+
+static int tr2_sysenv_cb(const char *key, const char *value, void *d)
+{
+	int k;
+
+	if (!starts_with(key, "trace2."))
+		return 0;
+
+	for (k = 0; k < ARRAY_SIZE(tr2_sysenv_settings); k++) {
+		if (!strcmp(key, tr2_sysenv_settings[k].git_config_name)) {
+			free(tr2_sysenv_settings[k].value);
+			tr2_sysenv_settings[k].value = xstrdup(value);
+			return 0;
+		}
+	}
+
+	return 0;
+}
+
+/*
+ * Load Trace2 settings from the system config (usually "/etc/gitconfig"
+ * unless we were built with a runtime-prefix).  These are intended to
+ * define the default values for Trace2 as requested by the administrator.
+ */
+void tr2_sysenv_load(void)
+{
+	const char *system_config_pathname;
+	const char *test_pathname;
+
+	system_config_pathname = git_etc_gitconfig();
+
+	test_pathname = getenv("GIT_TEST_TR2_SYSTEM_CONFIG");
+	if (test_pathname) {
+		if (!*test_pathname || !strcmp(test_pathname, "0"))
+			return; /* disable use of system config */
+
+		/* mock it with given test file */
+		system_config_pathname = test_pathname;
+	}
+
+	if (file_exists(system_config_pathname))
+		git_config_from_file(tr2_sysenv_cb, system_config_pathname,
+				     NULL);
+}
+
+/*
+ * Return the value for the requested setting.  Start with the /etc/gitconfig
+ * value and allow the corresponding environment variable to override it.
+ */
+const char *tr2_sysenv_get(enum tr2_sysenv_variable var)
+{
+	if (var >= TR2_SYSENV_MUST_BE_LAST)
+		BUG("tr2_sysenv_get invalid var '%d'", var);
+
+	if (!tr2_sysenv_settings[var].getenv_called) {
+		const char *v = getenv(tr2_sysenv_settings[var].env_var_name);
+		if (v && *v) {
+			free(tr2_sysenv_settings[var].value);
+			tr2_sysenv_settings[var].value = xstrdup(v);
+		}
+		tr2_sysenv_settings[var].getenv_called = 1;
+	}
+
+	return tr2_sysenv_settings[var].value;
+}
+
+/*
+ * Return a friendly name for this setting that is suitable for printing
+ * in an error messages.
+ */
+const char *tr2_sysenv_display_name(enum tr2_sysenv_variable var)
+{
+	if (var >= TR2_SYSENV_MUST_BE_LAST)
+		BUG("tr2_sysenv_get invalid var '%d'", var);
+
+	return tr2_sysenv_settings[var].env_var_name;
+}
+
+void tr2_sysenv_release(void)
+{
+	int k;
+
+	for (k = 0; k < ARRAY_SIZE(tr2_sysenv_settings); k++)
+		free(tr2_sysenv_settings[k].value);
+}
diff --git a/trace2/tr2_sysenv.h b/trace2/tr2_sysenv.h
new file mode 100644
index 0000000000..369b20bd87
--- /dev/null
+++ b/trace2/tr2_sysenv.h
@@ -0,0 +1,36 @@
+#ifndef TR2_SYSENV_H
+#define TR2_SYSENV_H
+
+/*
+ * The Trace2 settings that can be loaded from /etc/gitconfig
+ * and/or user environment variables.
+ *
+ * Note that this set does not contain any of the transient
+ * environment variables used to pass information from parent
+ * to child git processes, such "GIT_TR2_PARENT_SID".
+ */
+enum tr2_sysenv_variable {
+	TR2_SYSENV_CFG_PARAM = 0,
+
+	TR2_SYSENV_DST_DEBUG,
+
+	TR2_SYSENV_NORMAL,
+	TR2_SYSENV_NORMAL_BRIEF,
+
+	TR2_SYSENV_EVENT,
+	TR2_SYSENV_EVENT_BRIEF,
+	TR2_SYSENV_EVENT_NESTING,
+
+	TR2_SYSENV_PERF,
+	TR2_SYSENV_PERF_BRIEF,
+
+	TR2_SYSENV_MUST_BE_LAST
+};
+
+void tr2_sysenv_load(void);
+
+const char *tr2_sysenv_get(enum tr2_sysenv_variable);
+const char *tr2_sysenv_display_name(enum tr2_sysenv_variable var);
+void tr2_sysenv_release(void);
+
+#endif /* TR2_SYSENV_H */
diff --git a/trace2/tr2_tgt_event.c b/trace2/tr2_tgt_event.c
index 89a4d3ae9a..48d9193b2c 100644
--- a/trace2/tr2_tgt_event.c
+++ b/trace2/tr2_tgt_event.c
@@ -6,10 +6,11 @@
 #include "trace2/tr2_dst.h"
 #include "trace2/tr2_tbuf.h"
 #include "trace2/tr2_sid.h"
+#include "trace2/tr2_sysenv.h"
 #include "trace2/tr2_tgt.h"
 #include "trace2/tr2_tls.h"
 
-static struct tr2_dst tr2dst_event = { "GIT_TR2_EVENT", 0, 0, 0 };
+static struct tr2_dst tr2dst_event = { TR2_SYSENV_EVENT, 0, 0, 0 };
 
 /*
  * The version number of the JSON data generated by the EVENT target
@@ -28,37 +29,36 @@ static struct tr2_dst tr2dst_event = { "GIT_TR2_EVENT", 0, 0, 0 };
  * are primarily intended for the performance target during debugging.
  *
  * Some of the outer-most messages, however, may be of interest to the
- * event target.  Set this environment variable to a larger integer for
- * more detail in the event target.
+ * event target.  Use the TR2_SYSENV_EVENT_NESTING setting to increase
+ * region details in the event target.
  */
-#define TR2_ENVVAR_EVENT_NESTING "GIT_TR2_EVENT_NESTING"
-static int tr2env_event_nesting_wanted = 2;
+static int tr2env_event_max_nesting_levels = 2;
 
 /*
- * Set this environment variable to true to omit the <time>, <file>, and
+ * Use the TR2_SYSENV_EVENT_BRIEF to omit the <time>, <file>, and
  * <line> fields from most events.
  */
-#define TR2_ENVVAR_EVENT_BRIEF "GIT_TR2_EVENT_BRIEF"
-static int tr2env_event_brief;
+static int tr2env_event_be_brief;
 
 static int fn_init(void)
 {
 	int want = tr2_dst_trace_want(&tr2dst_event);
-	int want_nesting;
+	int max_nesting;
 	int want_brief;
-	char *nesting;
-	char *brief;
+	const char *nesting;
+	const char *brief;
 
 	if (!want)
 		return want;
 
-	nesting = getenv(TR2_ENVVAR_EVENT_NESTING);
-	if (nesting && ((want_nesting = atoi(nesting)) > 0))
-		tr2env_event_nesting_wanted = want_nesting;
+	nesting = tr2_sysenv_get(TR2_SYSENV_EVENT_NESTING);
+	if (nesting && *nesting && ((max_nesting = atoi(nesting)) > 0))
+		tr2env_event_max_nesting_levels = max_nesting;
 
-	brief = getenv(TR2_ENVVAR_EVENT_BRIEF);
-	if (brief && ((want_brief = atoi(brief)) > 0))
-		tr2env_event_brief = want_brief;
+	brief = tr2_sysenv_get(TR2_SYSENV_EVENT_BRIEF);
+	if (brief && *brief &&
+	    ((want_brief = git_parse_maybe_bool(brief)) != -1))
+		tr2env_event_be_brief = want_brief;
 
 	return want;
 }
@@ -92,13 +92,13 @@ static void event_fmt_prepare(const char *event_name, const char *file,
 	/*
 	 * In brief mode, only emit <time> on these 2 event types.
 	 */
-	if (!tr2env_event_brief || !strcmp(event_name, "version") ||
+	if (!tr2env_event_be_brief || !strcmp(event_name, "version") ||
 	    !strcmp(event_name, "atexit")) {
 		tr2_tbuf_utc_time(&tb_now);
 		jw_object_string(jw, "time", tb_now.buf);
 	}
 
-	if (!tr2env_event_brief && file && *file) {
+	if (!tr2env_event_be_brief && file && *file) {
 		jw_object_string(jw, "file", file);
 		jw_object_intmax(jw, "line", line);
 	}
@@ -459,7 +459,7 @@ static void fn_region_enter_printf_va_fl(const char *file, int line,
 {
 	const char *event_name = "region_enter";
 	struct tr2tls_thread_ctx *ctx = tr2tls_get_self();
-	if (ctx->nr_open_regions <= tr2env_event_nesting_wanted) {
+	if (ctx->nr_open_regions <= tr2env_event_max_nesting_levels) {
 		struct json_writer jw = JSON_WRITER_INIT;
 
 		jw_object_begin(&jw, 0);
@@ -484,7 +484,7 @@ static void fn_region_leave_printf_va_fl(
 {
 	const char *event_name = "region_leave";
 	struct tr2tls_thread_ctx *ctx = tr2tls_get_self();
-	if (ctx->nr_open_regions <= tr2env_event_nesting_wanted) {
+	if (ctx->nr_open_regions <= tr2env_event_max_nesting_levels) {
 		struct json_writer jw = JSON_WRITER_INIT;
 		double t_rel = (double)us_elapsed_region / 1000000.0;
 
@@ -511,7 +511,7 @@ static void fn_data_fl(const char *file, int line, uint64_t us_elapsed_absolute,
 {
 	const char *event_name = "data";
 	struct tr2tls_thread_ctx *ctx = tr2tls_get_self();
-	if (ctx->nr_open_regions <= tr2env_event_nesting_wanted) {
+	if (ctx->nr_open_regions <= tr2env_event_max_nesting_levels) {
 		struct json_writer jw = JSON_WRITER_INIT;
 		double t_abs = (double)us_elapsed_absolute / 1000000.0;
 		double t_rel = (double)us_elapsed_region / 1000000.0;
@@ -539,7 +539,7 @@ static void fn_data_json_fl(const char *file, int line,
 {
 	const char *event_name = "data_json";
 	struct tr2tls_thread_ctx *ctx = tr2tls_get_self();
-	if (ctx->nr_open_regions <= tr2env_event_nesting_wanted) {
+	if (ctx->nr_open_regions <= tr2env_event_max_nesting_levels) {
 		struct json_writer jw = JSON_WRITER_INIT;
 		double t_abs = (double)us_elapsed_absolute / 1000000.0;
 		double t_rel = (double)us_elapsed_region / 1000000.0;
diff --git a/trace2/tr2_tgt_normal.c b/trace2/tr2_tgt_normal.c
index 57f3e18f5b..1ce6f97863 100644
--- a/trace2/tr2_tgt_normal.c
+++ b/trace2/tr2_tgt_normal.c
@@ -4,20 +4,20 @@
 #include "quote.h"
 #include "version.h"
 #include "trace2/tr2_dst.h"
+#include "trace2/tr2_sysenv.h"
 #include "trace2/tr2_tbuf.h"
 #include "trace2/tr2_tgt.h"
 #include "trace2/tr2_tls.h"
 
-static struct tr2_dst tr2dst_normal = { "GIT_TR2", 0, 0, 0 };
+static struct tr2_dst tr2dst_normal = { TR2_SYSENV_NORMAL, 0, 0, 0 };
 
 /*
- * Set this environment variable to true to omit the "<time> <file>:<line>"
+ * Use the TR2_SYSENV_NORMAL_BRIEF setting to omit the "<time> <file>:<line>"
  * fields from each line written to the builtin normal target.
  *
  * Unit tests may want to use this to help with testing.
  */
-#define TR2_ENVVAR_NORMAL_BRIEF "GIT_TR2_BRIEF"
-static int tr2env_normal_brief;
+static int tr2env_normal_be_brief;
 
 #define TR2FMT_NORMAL_FL_WIDTH (50)
 
@@ -25,15 +25,15 @@ static int fn_init(void)
 {
 	int want = tr2_dst_trace_want(&tr2dst_normal);
 	int want_brief;
-	char *brief;
+	const char *brief;
 
 	if (!want)
 		return want;
 
-	brief = getenv(TR2_ENVVAR_NORMAL_BRIEF);
+	brief = tr2_sysenv_get(TR2_SYSENV_NORMAL_BRIEF);
 	if (brief && *brief &&
 	    ((want_brief = git_parse_maybe_bool(brief)) != -1))
-		tr2env_normal_brief = want_brief;
+		tr2env_normal_be_brief = want_brief;
 
 	return want;
 }
@@ -47,7 +47,7 @@ static void normal_fmt_prepare(const char *file, int line, struct strbuf *buf)
 {
 	strbuf_setlen(buf, 0);
 
-	if (!tr2env_normal_brief) {
+	if (!tr2env_normal_be_brief) {
 		struct tr2_tbuf tb_now;
 
 		tr2_tbuf_local_time(&tb_now);
diff --git a/trace2/tr2_tgt_perf.c b/trace2/tr2_tgt_perf.c
index 9c3b4d8a0f..328d2234bd 100644
--- a/trace2/tr2_tgt_perf.c
+++ b/trace2/tr2_tgt_perf.c
@@ -6,20 +6,20 @@
 #include "json-writer.h"
 #include "trace2/tr2_dst.h"
 #include "trace2/tr2_sid.h"
+#include "trace2/tr2_sysenv.h"
 #include "trace2/tr2_tbuf.h"
 #include "trace2/tr2_tgt.h"
 #include "trace2/tr2_tls.h"
 
-static struct tr2_dst tr2dst_perf = { "GIT_TR2_PERF", 0, 0, 0 };
+static struct tr2_dst tr2dst_perf = { TR2_SYSENV_PERF, 0, 0, 0 };
 
 /*
- * Set this environment variable to true to omit the "<time> <file>:<line>"
+ * Use TR2_SYSENV_PERF_BRIEF to omit the "<time> <file>:<line>"
  * fields from each line written to the builtin performance target.
  *
  * Unit tests may want to use this to help with testing.
  */
-#define TR2_ENVVAR_PERF_BRIEF "GIT_TR2_PERF_BRIEF"
-static int tr2env_perf_brief;
+static int tr2env_perf_be_brief;
 
 #define TR2FMT_PERF_FL_WIDTH (50)
 #define TR2FMT_PERF_MAX_EVENT_NAME (12)
@@ -36,17 +36,17 @@ static int fn_init(void)
 {
 	int want = tr2_dst_trace_want(&tr2dst_perf);
 	int want_brief;
-	char *brief;
+	const char *brief;
 
 	if (!want)
 		return want;
 
 	strbuf_addchars(&dots, '.', TR2_DOTS_BUFFER_SIZE);
 
-	brief = getenv(TR2_ENVVAR_PERF_BRIEF);
+	brief = tr2_sysenv_get(TR2_SYSENV_PERF_BRIEF);
 	if (brief && *brief &&
 	    ((want_brief = git_parse_maybe_bool(brief)) != -1))
-		tr2env_perf_brief = want_brief;
+		tr2env_perf_be_brief = want_brief;
 
 	return want;
 }
@@ -77,7 +77,7 @@ static void perf_fmt_prepare(const char *event_name,
 
 	strbuf_setlen(buf, 0);
 
-	if (!tr2env_perf_brief) {
+	if (!tr2env_perf_be_brief) {
 		struct tr2_tbuf tb_now;
 
 		tr2_tbuf_local_time(&tb_now);
-- 
gitgitgadget


^ permalink raw reply	[flat|nested] 68+ messages in thread

* [PATCH v2 5/7] trace2: report peak memory usage of the process
  2019-03-29 17:04 ` [PATCH v2 0/7] trace2: load trace2 settings from system config Jeff Hostetler via GitGitGadget
                     ` (3 preceding siblings ...)
  2019-03-29 17:04   ` [PATCH v2 4/7] trace2: use system config for default trace2 settings Jeff Hostetler via GitGitGadget
@ 2019-03-29 17:04   ` Jeff Hostetler via GitGitGadget
  2019-03-29 22:16     ` Ævar Arnfjörð Bjarmason
  2019-03-29 17:04   ` [PATCH v2 6/7] trace2: clarify UTC datetime formatting Jeff Hostetler via GitGitGadget
                     ` (3 subsequent siblings)
  8 siblings, 1 reply; 68+ messages in thread
From: Jeff Hostetler via GitGitGadget @ 2019-03-29 17:04 UTC (permalink / raw)
  To: git
  Cc: gitster, peff, jrnieder, steadmon, avarab, Junio C Hamano,
	Jeff Hostetler

From: Jeff Hostetler <jeffhost@microsoft.com>

Teach Windows version of git to report peak memory usage
during exit() processing.

Signed-off-by: Jeff Hostetler <jeffhost@microsoft.com>
---
 common-main.c                            |  2 +-
 compat/win32/trace2_win32_process_info.c | 50 ++++++++++++++++++++++--
 trace2.c                                 |  2 +
 trace2.h                                 | 14 +++++--
 4 files changed, 60 insertions(+), 8 deletions(-)

diff --git a/common-main.c b/common-main.c
index 299ca62a72..582a7b1886 100644
--- a/common-main.c
+++ b/common-main.c
@@ -41,7 +41,7 @@ int main(int argc, const char **argv)
 
 	trace2_initialize();
 	trace2_cmd_start(argv);
-	trace2_collect_process_info();
+	trace2_collect_process_info(TRACE2_PROCESS_INFO_STARTUP);
 
 	git_setup_gettext();
 
diff --git a/compat/win32/trace2_win32_process_info.c b/compat/win32/trace2_win32_process_info.c
index 52bd62034b..2a514caed9 100644
--- a/compat/win32/trace2_win32_process_info.c
+++ b/compat/win32/trace2_win32_process_info.c
@@ -1,5 +1,6 @@
 #include "../../cache.h"
 #include "../../json-writer.h"
+#include "lazyload.h"
 #include <Psapi.h>
 #include <tlHelp32.h>
 
@@ -137,11 +138,54 @@ static void get_is_being_debugged(void)
 				   "windows/debugger_present", 1);
 }
 
-void trace2_collect_process_info(void)
+/*
+ * Emit JSON data with the peak memory usage of the current process.
+ */
+static void get_peak_memory_info(void)
+{
+	DECLARE_PROC_ADDR(psapi.dll, BOOL, GetProcessMemoryInfo,
+			  HANDLE, PPROCESS_MEMORY_COUNTERS, DWORD);
+
+	if (INIT_PROC_ADDR(GetProcessMemoryInfo)) {
+		PROCESS_MEMORY_COUNTERS pmc;
+
+		if (GetProcessMemoryInfo(GetCurrentProcess(), &pmc,
+					 sizeof(pmc))) {
+			struct json_writer jw = JSON_WRITER_INIT;
+
+			jw_object_begin(&jw, 0);
+
+#define KV(kv) #kv, (intmax_t)pmc.kv
+
+			jw_object_intmax(&jw, KV(PageFaultCount));
+			jw_object_intmax(&jw, KV(PeakWorkingSetSize));
+			jw_object_intmax(&jw, KV(PeakPagefileUsage));
+
+			jw_end(&jw);
+
+			trace2_data_json("process", the_repository,
+					 "windows/memory", &jw);
+			jw_release(&jw);
+		}
+	}
+}
+
+void trace2_collect_process_info(enum trace2_process_info_reason reason)
 {
 	if (!trace2_is_enabled())
 		return;
 
-	get_is_being_debugged();
-	get_ancestry();
+	switch (reason) {
+	case TRACE2_PROCESS_INFO_STARTUP:
+		get_is_being_debugged();
+		get_ancestry();
+		return;
+
+	case TRACE2_PROCESS_INFO_EXIT:
+		get_peak_memory_info();
+		return;
+
+	default:
+		BUG("trace2_collect_process_info: unknown reason '%d'", reason);
+	}
 }
diff --git a/trace2.c b/trace2.c
index 490b3f071e..6baa65cdf9 100644
--- a/trace2.c
+++ b/trace2.c
@@ -213,6 +213,8 @@ int trace2_cmd_exit_fl(const char *file, int line, int code)
 	if (!trace2_enabled)
 		return code;
 
+	trace2_collect_process_info(TRACE2_PROCESS_INFO_EXIT);
+
 	tr2main_exit_code = code;
 
 	us_now = getnanotime() / 1000;
diff --git a/trace2.h b/trace2.h
index 894bfca7e0..888531eb08 100644
--- a/trace2.h
+++ b/trace2.h
@@ -391,13 +391,19 @@ void trace2_printf(const char *fmt, ...);
  * Optional platform-specific code to dump information about the
  * current and any parent process(es).  This is intended to allow
  * post-processors to know who spawned this git instance and anything
- * else the platform may be able to tell us about the current process.
+ * else that the platform may be able to tell us about the current process.
  */
+
+enum trace2_process_info_reason {
+	TRACE2_PROCESS_INFO_STARTUP,
+	TRACE2_PROCESS_INFO_EXIT,
+};
+
 #if defined(GIT_WINDOWS_NATIVE)
-void trace2_collect_process_info(void);
+void trace2_collect_process_info(enum trace2_process_info_reason reason);
 #else
-#define trace2_collect_process_info() \
-	do {                          \
+#define trace2_collect_process_info(reason) \
+	do {                                \
 	} while (0)
 #endif
 
-- 
gitgitgadget


^ permalink raw reply	[flat|nested] 68+ messages in thread

* [PATCH v2 6/7] trace2: clarify UTC datetime formatting
  2019-03-29 17:04 ` [PATCH v2 0/7] trace2: load trace2 settings from system config Jeff Hostetler via GitGitGadget
                     ` (4 preceding siblings ...)
  2019-03-29 17:04   ` [PATCH v2 5/7] trace2: report peak memory usage of the process Jeff Hostetler via GitGitGadget
@ 2019-03-29 17:04   ` Jeff Hostetler via GitGitGadget
  2019-03-29 17:04   ` [PATCH v2 7/7] trace2: make SIDs more unique Jeff Hostetler via GitGitGadget
                     ` (2 subsequent siblings)
  8 siblings, 0 replies; 68+ messages in thread
From: Jeff Hostetler via GitGitGadget @ 2019-03-29 17:04 UTC (permalink / raw)
  To: git
  Cc: gitster, peff, jrnieder, steadmon, avarab, Junio C Hamano,
	Jeff Hostetler

From: Jeff Hostetler <jeffhost@microsoft.com>

Update tr2_tbuf_utc_datetime to generate extended UTC format.
Update tr2_tgt_event target to use extended format in 'time' columns.

Signed-off-by: Jeff Hostetler <jeffhost@microsoft.com>
---
 Documentation/technical/api-trace2.txt | 12 ++++++------
 trace2/tr2_tbuf.c                      |  4 ++--
 trace2/tr2_tbuf.h                      |  4 ++--
 trace2/tr2_tgt_event.c                 |  2 +-
 4 files changed, 11 insertions(+), 11 deletions(-)

diff --git a/Documentation/technical/api-trace2.txt b/Documentation/technical/api-trace2.txt
index 13ca595c69..db968e31f7 100644
--- a/Documentation/technical/api-trace2.txt
+++ b/Documentation/technical/api-trace2.txt
@@ -78,11 +78,11 @@ git version 2.20.1.155.g426c96fcdb
 +
 ------------
 $ cat ~/log.event
-{"event":"version","sid":"1547659722619736-11614","thread":"main","time":"2019-01-16 17:28:42.620713","file":"common-main.c","line":38,"evt":"1","exe":"2.20.1.155.g426c96fcdb"}
-{"event":"start","sid":"1547659722619736-11614","thread":"main","time":"2019-01-16 17:28:42.621027","file":"common-main.c","line":39,"t_abs":0.001173,"argv":["git","version"]}
-{"event":"cmd_name","sid":"1547659722619736-11614","thread":"main","time":"2019-01-16 17:28:42.621122","file":"git.c","line":432,"name":"version","hierarchy":"version"}
-{"event":"exit","sid":"1547659722619736-11614","thread":"main","time":"2019-01-16 17:28:42.621236","file":"git.c","line":662,"t_abs":0.001227,"code":0}
-{"event":"atexit","sid":"1547659722619736-11614","thread":"main","time":"2019-01-16 17:28:42.621268","file":"trace2/tr2_tgt_event.c","line":163,"t_abs":0.001265,"code":0}
+{"event":"version","sid":"1547659722619736-11614","thread":"main","time":"2019-01-16T17:28:42.620713Z","file":"common-main.c","line":38,"evt":"1","exe":"2.20.1.155.g426c96fcdb"}
+{"event":"start","sid":"1547659722619736-11614","thread":"main","time":"2019-01-16T17:28:42.621027Z","file":"common-main.c","line":39,"t_abs":0.001173,"argv":["git","version"]}
+{"event":"cmd_name","sid":"1547659722619736-11614","thread":"main","time":"2019-01-16T17:28:42.621122Z","file":"git.c","line":432,"name":"version","hierarchy":"version"}
+{"event":"exit","sid":"1547659722619736-11614","thread":"main","time":"2019-01-16T17:28:42.621236Z","file":"git.c","line":662,"t_abs":0.001227,"code":0}
+{"event":"atexit","sid":"1547659722619736-11614","thread":"main","time":"2019-01-16T17:28:42.621268Z","file":"trace2/tr2_tgt_event.c","line":163,"t_abs":0.001265,"code":0}
 ------------
 
 == Enabling a Target
@@ -573,7 +573,7 @@ The following key/value pairs are common to all events:
 	"event":"version",
 	"sid":"1547659722619736-11614",
 	"thread":"main",
-	"time":"2019-01-16 17:28:42.620713",
+	"time":"2019-01-16T17:28:42.620713Z",
 	"file":"common-main.c",
 	"line":38,
 	...
diff --git a/trace2/tr2_tbuf.c b/trace2/tr2_tbuf.c
index 0844910423..eb1b240d8a 100644
--- a/trace2/tr2_tbuf.c
+++ b/trace2/tr2_tbuf.c
@@ -15,7 +15,7 @@ void tr2_tbuf_local_time(struct tr2_tbuf *tb)
 		  tm.tm_min, tm.tm_sec, (long)tv.tv_usec);
 }
 
-void tr2_tbuf_utc_time(struct tr2_tbuf *tb)
+void tr2_tbuf_utc_datetime_extended(struct tr2_tbuf *tb)
 {
 	struct timeval tv;
 	struct tm tm;
@@ -26,7 +26,7 @@ void tr2_tbuf_utc_time(struct tr2_tbuf *tb)
 	gmtime_r(&secs, &tm);
 
 	xsnprintf(tb->buf, sizeof(tb->buf),
-		  "%4d-%02d-%02d %02d:%02d:%02d.%06ld", tm.tm_year + 1900,
+		  "%4d-%02d-%02dT%02d:%02d:%02d.%06ldZ", tm.tm_year + 1900,
 		  tm.tm_mon + 1, tm.tm_mday, tm.tm_hour, tm.tm_min, tm.tm_sec,
 		  (long)tv.tv_usec);
 }
diff --git a/trace2/tr2_tbuf.h b/trace2/tr2_tbuf.h
index 9cdefa3957..2a1d173ff2 100644
--- a/trace2/tr2_tbuf.h
+++ b/trace2/tr2_tbuf.h
@@ -16,8 +16,8 @@ struct tr2_tbuf {
 void tr2_tbuf_local_time(struct tr2_tbuf *tb);
 
 /*
- * Fill buffer with formatted UTC time string.
+ * Fill buffer with formatted UTC datatime string.
  */
-void tr2_tbuf_utc_time(struct tr2_tbuf *tb);
+void tr2_tbuf_utc_datetime_extended(struct tr2_tbuf *tb);
 
 #endif /* TR2_TBUF_H */
diff --git a/trace2/tr2_tgt_event.c b/trace2/tr2_tgt_event.c
index 48d9193b2c..2c97cf54be 100644
--- a/trace2/tr2_tgt_event.c
+++ b/trace2/tr2_tgt_event.c
@@ -94,7 +94,7 @@ static void event_fmt_prepare(const char *event_name, const char *file,
 	 */
 	if (!tr2env_event_be_brief || !strcmp(event_name, "version") ||
 	    !strcmp(event_name, "atexit")) {
-		tr2_tbuf_utc_time(&tb_now);
+		tr2_tbuf_utc_datetime_extended(&tb_now);
 		jw_object_string(jw, "time", tb_now.buf);
 	}
 
-- 
gitgitgadget


^ permalink raw reply	[flat|nested] 68+ messages in thread

* [PATCH v2 7/7] trace2: make SIDs more unique
  2019-03-29 17:04 ` [PATCH v2 0/7] trace2: load trace2 settings from system config Jeff Hostetler via GitGitGadget
                     ` (5 preceding siblings ...)
  2019-03-29 17:04   ` [PATCH v2 6/7] trace2: clarify UTC datetime formatting Jeff Hostetler via GitGitGadget
@ 2019-03-29 17:04   ` Jeff Hostetler via GitGitGadget
  2019-03-29 22:12     ` Ævar Arnfjörð Bjarmason
  2019-04-01 21:02   ` [PATCH v2 0/7] trace2: load trace2 settings from system config Josh Steadmon
  2019-04-11 15:18   ` [PATCH v3 00/10] " Jeff Hostetler via GitGitGadget
  8 siblings, 1 reply; 68+ messages in thread
From: Jeff Hostetler via GitGitGadget @ 2019-03-29 17:04 UTC (permalink / raw)
  To: git
  Cc: gitster, peff, jrnieder, steadmon, avarab, Junio C Hamano,
	Jeff Hostetler

From: Jeff Hostetler <jeffhost@microsoft.com>

Update SID component construction to use the current UTC datetime
and a portion of the SHA1 of the hostname.

Use an simplified date/time format to make it easier to use the
SID component as a logfile filename.

Signed-off-by: Jeff Hostetler <jeffhost@microsoft.com>
---
 Documentation/technical/api-trace2.txt | 12 ++++----
 trace2/tr2_sid.c                       | 39 +++++++++++++++++++++++---
 trace2/tr2_tbuf.c                      | 16 +++++++++++
 trace2/tr2_tbuf.h                      |  1 +
 4 files changed, 58 insertions(+), 10 deletions(-)

diff --git a/Documentation/technical/api-trace2.txt b/Documentation/technical/api-trace2.txt
index db968e31f7..e740db3907 100644
--- a/Documentation/technical/api-trace2.txt
+++ b/Documentation/technical/api-trace2.txt
@@ -78,11 +78,11 @@ git version 2.20.1.155.g426c96fcdb
 +
 ------------
 $ cat ~/log.event
-{"event":"version","sid":"1547659722619736-11614","thread":"main","time":"2019-01-16T17:28:42.620713Z","file":"common-main.c","line":38,"evt":"1","exe":"2.20.1.155.g426c96fcdb"}
-{"event":"start","sid":"1547659722619736-11614","thread":"main","time":"2019-01-16T17:28:42.621027Z","file":"common-main.c","line":39,"t_abs":0.001173,"argv":["git","version"]}
-{"event":"cmd_name","sid":"1547659722619736-11614","thread":"main","time":"2019-01-16T17:28:42.621122Z","file":"git.c","line":432,"name":"version","hierarchy":"version"}
-{"event":"exit","sid":"1547659722619736-11614","thread":"main","time":"2019-01-16T17:28:42.621236Z","file":"git.c","line":662,"t_abs":0.001227,"code":0}
-{"event":"atexit","sid":"1547659722619736-11614","thread":"main","time":"2019-01-16T17:28:42.621268Z","file":"trace2/tr2_tgt_event.c","line":163,"t_abs":0.001265,"code":0}
+{"event":"version","sid":"20190329-144314-319944-9b68c35f-012232","thread":"main","time":"2019-01-16T17:28:42.620713Z","file":"common-main.c","line":38,"evt":"1","exe":"2.20.1.155.g426c96fcdb"}
+{"event":"start","sid":"20190329-144314-319944-9b68c35f-012232","thread":"main","time":"2019-01-16T17:28:42.621027Z","file":"common-main.c","line":39,"t_abs":0.001173,"argv":["git","version"]}
+{"event":"cmd_name","sid":"20190329-144314-319944-9b68c35f-012232","thread":"main","time":"2019-01-16T17:28:42.621122Z","file":"git.c","line":432,"name":"version","hierarchy":"version"}
+{"event":"exit","sid":"20190329-144314-319944-9b68c35f-012232","thread":"main","time":"2019-01-16T17:28:42.621236Z","file":"git.c","line":662,"t_abs":0.001227,"code":0}
+{"event":"atexit","sid":"20190329-144314-319944-9b68c35f-012232","thread":"main","time":"2019-01-16T17:28:42.621268Z","file":"trace2/tr2_tgt_event.c","line":163,"t_abs":0.001265,"code":0}
 ------------
 
 == Enabling a Target
@@ -571,7 +571,7 @@ The following key/value pairs are common to all events:
 ------------
 {
 	"event":"version",
-	"sid":"1547659722619736-11614",
+	"sid":"20190329-144314-319944-9b68c35f-012232",
 	"thread":"main",
 	"time":"2019-01-16T17:28:42.620713Z",
 	"file":"common-main.c",
diff --git a/trace2/tr2_sid.c b/trace2/tr2_sid.c
index 984524a43c..6801113e53 100644
--- a/trace2/tr2_sid.c
+++ b/trace2/tr2_sid.c
@@ -1,4 +1,5 @@
 #include "cache.h"
+#include "trace2/tr2_tbuf.h"
 #include "trace2/tr2_sid.h"
 
 #define TR2_ENVVAR_PARENT_SID "GIT_TR2_PARENT_SID"
@@ -6,6 +7,39 @@
 static struct strbuf tr2sid_buf = STRBUF_INIT;
 static int tr2sid_nr_git_parents;
 
+/*
+ * Compute the final component of the SID representing the current process.
+ * This should uniquely identify the process and be a valid filename (to
+ * allow writing trace2 data to per-process files).
+ *
+ * <yyyymmdd> '-' <hhmmss> '-' <fraction> '-' <sha1-prefix> '-' <pid>
+ */
+static void tr2_sid_append_my_sid_component(void)
+{
+	const struct git_hash_algo *algo = &hash_algos[GIT_HASH_SHA1];
+	struct tr2_tbuf tb_now;
+	git_hash_ctx ctx;
+	unsigned char hash[GIT_MAX_RAWSZ + 1];
+	char hex[GIT_MAX_HEXSZ + 1];
+	char hostname[HOST_NAME_MAX + 1];
+
+	tr2_tbuf_utc_datetime_for_filename(&tb_now);
+	strbuf_addstr(&tr2sid_buf, tb_now.buf);
+	strbuf_addch(&tr2sid_buf, '-');
+
+	if (xgethostname(hostname, sizeof(hostname)))
+		xsnprintf(hostname, sizeof(hostname), "localhost");
+
+	algo->init_fn(&ctx);
+	algo->update_fn(&ctx, hostname, strlen(hostname));
+	algo->final_fn(hash, &ctx);
+	hash_to_hex_algop_r(hex, hash, algo);
+	strbuf_add(&tr2sid_buf, hex, 8);
+
+	strbuf_addch(&tr2sid_buf, '-');
+	strbuf_addf(&tr2sid_buf, "%06"PRIuMAX, (uintmax_t)getpid());
+}
+
 /*
  * Compute a "unique" session id (SID) for the current process.  This allows
  * all events from this process to have a single label (much like a PID).
@@ -20,7 +54,6 @@ static int tr2sid_nr_git_parents;
  */
 static void tr2_sid_compute(void)
 {
-	uint64_t us_now;
 	const char *parent_sid;
 
 	if (tr2sid_buf.len)
@@ -38,9 +71,7 @@ static void tr2_sid_compute(void)
 		tr2sid_nr_git_parents++;
 	}
 
-	us_now = getnanotime() / 1000;
-	strbuf_addf(&tr2sid_buf, "%" PRIuMAX "-%" PRIdMAX, (uintmax_t)us_now,
-		    (intmax_t)getpid());
+	tr2_sid_append_my_sid_component();
 
 	setenv(TR2_ENVVAR_PARENT_SID, tr2sid_buf.buf, 1);
 }
diff --git a/trace2/tr2_tbuf.c b/trace2/tr2_tbuf.c
index eb1b240d8a..c1a50fe084 100644
--- a/trace2/tr2_tbuf.c
+++ b/trace2/tr2_tbuf.c
@@ -30,3 +30,19 @@ void tr2_tbuf_utc_datetime_extended(struct tr2_tbuf *tb)
 		  tm.tm_mon + 1, tm.tm_mday, tm.tm_hour, tm.tm_min, tm.tm_sec,
 		  (long)tv.tv_usec);
 }
+
+void tr2_tbuf_utc_datetime_for_filename(struct tr2_tbuf *tb)
+{
+	struct timeval tv;
+	struct tm tm;
+	time_t secs;
+
+	gettimeofday(&tv, NULL);
+	secs = tv.tv_sec;
+	gmtime_r(&secs, &tm);
+
+	xsnprintf(tb->buf, sizeof(tb->buf),
+		  "%4d%02d%02d-%02d%02d%02d-%06ld", tm.tm_year + 1900,
+		  tm.tm_mon + 1, tm.tm_mday, tm.tm_hour, tm.tm_min, tm.tm_sec,
+		  (long)tv.tv_usec);
+}
diff --git a/trace2/tr2_tbuf.h b/trace2/tr2_tbuf.h
index 2a1d173ff2..29efff1ef7 100644
--- a/trace2/tr2_tbuf.h
+++ b/trace2/tr2_tbuf.h
@@ -19,5 +19,6 @@ void tr2_tbuf_local_time(struct tr2_tbuf *tb);
  * Fill buffer with formatted UTC datatime string.
  */
 void tr2_tbuf_utc_datetime_extended(struct tr2_tbuf *tb);
+void tr2_tbuf_utc_datetime_for_filename(struct tr2_tbuf *tb);
 
 #endif /* TR2_TBUF_H */
-- 
gitgitgadget

^ permalink raw reply	[flat|nested] 68+ messages in thread

* Re: [PATCH v2 7/7] trace2: make SIDs more unique
  2019-03-29 17:04   ` [PATCH v2 7/7] trace2: make SIDs more unique Jeff Hostetler via GitGitGadget
@ 2019-03-29 22:12     ` Ævar Arnfjörð Bjarmason
  2019-04-01 21:16       ` Jeff Hostetler
  0 siblings, 1 reply; 68+ messages in thread
From: Ævar Arnfjörð Bjarmason @ 2019-03-29 22:12 UTC (permalink / raw)
  To: Jeff Hostetler via GitGitGadget
  Cc: git, peff, jrnieder, steadmon, Junio C Hamano, Jeff Hostetler


On Fri, Mar 29 2019, Jeff Hostetler via GitGitGadget wrote:

> From: Jeff Hostetler <jeffhost@microsoft.com>
>
> Update SID component construction to use the current UTC datetime
> and a portion of the SHA1 of the hostname.
>
> Use an simplified date/time format to make it easier to use the
> SID component as a logfile filename.
> [...]
> +static void tr2_sid_append_my_sid_component(void)
> +{
> +	const struct git_hash_algo *algo = &hash_algos[GIT_HASH_SHA1];
> +	struct tr2_tbuf tb_now;
> +	git_hash_ctx ctx;
> +	unsigned char hash[GIT_MAX_RAWSZ + 1];
> +	char hex[GIT_MAX_HEXSZ + 1];
> +	char hostname[HOST_NAME_MAX + 1];
> +
> +	tr2_tbuf_utc_datetime_for_filename(&tb_now);
> +	strbuf_addstr(&tr2sid_buf, tb_now.buf);
> +	strbuf_addch(&tr2sid_buf, '-');
> +
> +	if (xgethostname(hostname, sizeof(hostname)))
> +		xsnprintf(hostname, sizeof(hostname), "localhost");
> +
> +	algo->init_fn(&ctx);
> +	algo->update_fn(&ctx, hostname, strlen(hostname));
> +	algo->final_fn(hash, &ctx);
> +	hash_to_hex_algop_r(hex, hash, algo);
> +	strbuf_add(&tr2sid_buf, hex, 8);
> +
> +	strbuf_addch(&tr2sid_buf, '-');
> +	strbuf_addf(&tr2sid_buf, "%06"PRIuMAX, (uintmax_t)getpid());
> +}
> +

Thanks for turning my shitty half-formed idea into a patch :)

I wrote this on top to bikeshed this a bit further, wonder what you
think:
https://github.com/gitgitgadget/git/compare/pr-169/jeffhostetler/core-tr2-startup-and-sysenv-v2...avar:pr-169/jeffhostetler/core-tr2-startup-and-sysenv-v2

So e.g.:

    Before: 20190329-220413-446441-c2f5b994-018702
    After:  20190329T220431.244562Z-Hc2f5b994-P19812F

I.e:

 * Using <date>T<time> as is ISO 8601 convention/easier to read

 * <dateime>.<microseconds>Z, so seperating with "." to indicate it's
   the same value + add "Z" for "it's UTC". I'm least sure about the
   ".". Is that going to cause issues on Windows these days (the rest
   being the "extension"...).

 * I changed the hostname discovery so if gethostbyname() fails we'll
   print "-H00000000-" for that part, instead of "-H<first 8 chars of
   the sha1 for 'localhost'>-". Also prefix with "H" for "Host".

 * Wrap pids to 0xffff, prefix with "P" (Pid)" and trail with either "F"
   = Full or "W" = Wrapped (not the real PID).

 * I didn't add "T<datetime>" like "H" and "P" for the rest, since it's
   obvious what sort of value it is.

Maybe this is going a bit overboard, but I think it's easier to read at
a glance for humans, and since it's meant to be opaque to machines
anyway and the length is simliar enough not to matter I figure it's
worth it.


^ permalink raw reply	[flat|nested] 68+ messages in thread

* Re: [PATCH v2 5/7] trace2: report peak memory usage of the process
  2019-03-29 17:04   ` [PATCH v2 5/7] trace2: report peak memory usage of the process Jeff Hostetler via GitGitGadget
@ 2019-03-29 22:16     ` Ævar Arnfjörð Bjarmason
  2019-04-01 21:05       ` Jeff Hostetler
  0 siblings, 1 reply; 68+ messages in thread
From: Ævar Arnfjörð Bjarmason @ 2019-03-29 22:16 UTC (permalink / raw)
  To: Jeff Hostetler via GitGitGadget
  Cc: git, peff, jrnieder, steadmon, Junio C Hamano, Jeff Hostetler


On Fri, Mar 29 2019, Jeff Hostetler via GitGitGadget wrote:

> From: Jeff Hostetler <jeffhost@microsoft.com>
>
> Teach Windows version of git to report peak memory usage
> during exit() processing.
>
> Signed-off-by: Jeff Hostetler <jeffhost@microsoft.com>
> ---
>  common-main.c                            |  2 +-
>  compat/win32/trace2_win32_process_info.c | 50 ++++++++++++++++++++++--
>  trace2.c                                 |  2 +
>  trace2.h                                 | 14 +++++--
>  4 files changed, 60 insertions(+), 8 deletions(-)
>
> diff --git a/common-main.c b/common-main.c
> index 299ca62a72..582a7b1886 100644
> --- a/common-main.c
> +++ b/common-main.c
> @@ -41,7 +41,7 @@ int main(int argc, const char **argv)
>
>  	trace2_initialize();
>  	trace2_cmd_start(argv);
> -	trace2_collect_process_info();
> +	trace2_collect_process_info(TRACE2_PROCESS_INFO_STARTUP);
>
>  	git_setup_gettext();
>
> diff --git a/compat/win32/trace2_win32_process_info.c b/compat/win32/trace2_win32_process_info.c
> index 52bd62034b..2a514caed9 100644
> --- a/compat/win32/trace2_win32_process_info.c
> +++ b/compat/win32/trace2_win32_process_info.c
> @@ -1,5 +1,6 @@
>  #include "../../cache.h"
>  #include "../../json-writer.h"
> +#include "lazyload.h"
>  #include <Psapi.h>
>  #include <tlHelp32.h>
>
> @@ -137,11 +138,54 @@ static void get_is_being_debugged(void)
>  				   "windows/debugger_present", 1);
>  }
>
> -void trace2_collect_process_info(void)
> +/*
> + * Emit JSON data with the peak memory usage of the current process.
> + */
> +static void get_peak_memory_info(void)
> +{
> +	DECLARE_PROC_ADDR(psapi.dll, BOOL, GetProcessMemoryInfo,
> +			  HANDLE, PPROCESS_MEMORY_COUNTERS, DWORD);
> +
> +	if (INIT_PROC_ADDR(GetProcessMemoryInfo)) {
> +		PROCESS_MEMORY_COUNTERS pmc;
> +
> +		if (GetProcessMemoryInfo(GetCurrentProcess(), &pmc,
> +					 sizeof(pmc))) {
> +			struct json_writer jw = JSON_WRITER_INIT;
> +
> +			jw_object_begin(&jw, 0);
> +
> +#define KV(kv) #kv, (intmax_t)pmc.kv
> +
> +			jw_object_intmax(&jw, KV(PageFaultCount));
> +			jw_object_intmax(&jw, KV(PeakWorkingSetSize));
> +			jw_object_intmax(&jw, KV(PeakPagefileUsage));
> +
> +			jw_end(&jw);
> +
> +			trace2_data_json("process", the_repository,
> +					 "windows/memory", &jw);
> +			jw_release(&jw);
> +		}
> +	}
> +}
> +
> +void trace2_collect_process_info(enum trace2_process_info_reason reason)
>  {
>  	if (!trace2_is_enabled())
>  		return;
>
> -	get_is_being_debugged();
> -	get_ancestry();
> +	switch (reason) {
> +	case TRACE2_PROCESS_INFO_STARTUP:
> +		get_is_being_debugged();
> +		get_ancestry();
> +		return;
> +
> +	case TRACE2_PROCESS_INFO_EXIT:
> +		get_peak_memory_info();
> +		return;
> +
> +	default:
> +		BUG("trace2_collect_process_info: unknown reason '%d'", reason);
> +	}
>  }
> diff --git a/trace2.c b/trace2.c
> index 490b3f071e..6baa65cdf9 100644
> --- a/trace2.c
> +++ b/trace2.c
> @@ -213,6 +213,8 @@ int trace2_cmd_exit_fl(const char *file, int line, int code)
>  	if (!trace2_enabled)
>  		return code;
>
> +	trace2_collect_process_info(TRACE2_PROCESS_INFO_EXIT);
> +
>  	tr2main_exit_code = code;
>
>  	us_now = getnanotime() / 1000;
> diff --git a/trace2.h b/trace2.h
> index 894bfca7e0..888531eb08 100644
> --- a/trace2.h
> +++ b/trace2.h
> @@ -391,13 +391,19 @@ void trace2_printf(const char *fmt, ...);
>   * Optional platform-specific code to dump information about the
>   * current and any parent process(es).  This is intended to allow
>   * post-processors to know who spawned this git instance and anything
> - * else the platform may be able to tell us about the current process.
> + * else that the platform may be able to tell us about the current process.
>   */
> +
> +enum trace2_process_info_reason {
> +	TRACE2_PROCESS_INFO_STARTUP,
> +	TRACE2_PROCESS_INFO_EXIT,
> +};
> +
>  #if defined(GIT_WINDOWS_NATIVE)
> -void trace2_collect_process_info(void);
> +void trace2_collect_process_info(enum trace2_process_info_reason reason);
>  #else
> -#define trace2_collect_process_info() \
> -	do {                          \
> +#define trace2_collect_process_info(reason) \
> +	do {                                \
>  	} while (0)
>  #endif

FWIW this is the "VmPeak" line in /proc/$$/status on Linux. I don't know
if we can/should parse that in practice (I've been bitten in the past by
things in /proc having high cost on some kernel versions in the past,
notably smaps).

^ permalink raw reply	[flat|nested] 68+ messages in thread

* Re: [PATCH v2 4/7] trace2: use system config for default trace2 settings
  2019-03-29 17:04   ` [PATCH v2 4/7] trace2: use system config for default trace2 settings Jeff Hostetler via GitGitGadget
@ 2019-04-01 21:00     ` Josh Steadmon
  2019-04-01 21:06       ` Jeff Hostetler
  2019-04-03  0:01       ` Jonathan Nieder
  2019-04-03  0:00     ` Jonathan Nieder
  1 sibling, 2 replies; 68+ messages in thread
From: Josh Steadmon @ 2019-04-01 21:00 UTC (permalink / raw)
  To: Jeff Hostetler via GitGitGadget
  Cc: git, gitster, peff, jrnieder, avarab, Jeff Hostetler

On 2019.03.29 10:04, Jeff Hostetler via GitGitGadget wrote:
[...]
> diff --git a/Documentation/technical/api-trace2.txt b/Documentation/technical/api-trace2.txt
> index baaa1153bb..13ca595c69 100644
> --- a/Documentation/technical/api-trace2.txt
> +++ b/Documentation/technical/api-trace2.txt
> @@ -117,6 +117,37 @@ values are recognized.
>  Socket type can be either `stream` or `dgram`.  If the socket type is
>  omitted, Git will try both.
>  
> +== Trace2 Settings in System Config
> +
> +Trace2 also reads configuration information from the system config.
> +This is intended to help adminstrators to gather system-wide Git
> +performance data.
> +
> +Trace2 only reads the system configuration, it does not read global,
> +local, worktree, or `-c` config settings.
> +
> +Trace2 will try to load the following system configuration settings
> +and then read the corresponding environment variables at startup.
> +
> +....
> +---------------------------------------------------
> +trace2.normalTarget          GIT_TR2
> +trace2.normalBrief           GIT_TR2_BRIEF
> +
> +trace2.perfTarget            GIT_TR2_PERF
> +trace2.perfBrief             GIT_TR2_PERF_BRIEF
> +
> +trace2.eventTarget           GIT_TR2_EVENT
> +trace2.eventBrief            GIT_TR2_EVENT_BRIEF
> +trace2.eventNesting          GIT_TR2_EVENT_NESTING
> +
> +trace2.configParams          GIT_TR2_CONFIG_PARAMS
> +
> +trace2.destinationDebug      GIT_TR2_DST_DEBUG
> +---------------------------------------------------
> +....
> +
> +

A question for the list: should these new config vars also be documented
in the git-config manpage, or is it better to keep these separate since
they are only read from the system config?

^ permalink raw reply	[flat|nested] 68+ messages in thread

* Re: [PATCH v2 0/7] trace2: load trace2 settings from system config
  2019-03-29 17:04 ` [PATCH v2 0/7] trace2: load trace2 settings from system config Jeff Hostetler via GitGitGadget
                     ` (6 preceding siblings ...)
  2019-03-29 17:04   ` [PATCH v2 7/7] trace2: make SIDs more unique Jeff Hostetler via GitGitGadget
@ 2019-04-01 21:02   ` Josh Steadmon
  2019-04-11 15:18   ` [PATCH v3 00/10] " Jeff Hostetler via GitGitGadget
  8 siblings, 0 replies; 68+ messages in thread
From: Josh Steadmon @ 2019-04-01 21:02 UTC (permalink / raw)
  To: Jeff Hostetler via GitGitGadget; +Cc: git, gitster, peff, jrnieder, avarab

On 2019.03.29 10:04, Jeff Hostetler via GitGitGadget wrote:
> Here is version 2. It addresses most the V1 comments WRT the system config
> changes.
> 
> It also addresses the format and uniqueness of the SID as discussed in [1].
> The SID now containes: the UTC date/time, part of SHA1 of the hostname, and
> the PID and is formatted to make it safe for filenames.
> 
> It also contains (a somewhat unrelated platform-specific) commit to report
> total process memory usage at exit. This is helpful when looking for
> problematic commands that might have scaling problems.
> 
> [1] 
> https://public-inbox.org/git/51e88650-8667-df1f-13ef-4537f2e70346@jeffhostetler.com/T/#m6b4e6f2b0374d5ba88de8d0350ce6bf51b28d7da
> 
> 
> ----------------------------------------------------------------------------
> 
> Teach git to load default Trace2 settings from the system config (usually
> "/etc/gitconfig"). The existing GIT_TR2_* environment variables can be used
> to override the new system defaults. It also includes a little startup
> refactoring.
> 
> Note: I found interactive testing of this feature to be awkward on some
> platforms because of the use of prefix- or runtime-prefix-relative locations
> for the system configuration. It was easy to accidentally use an officially
> installed version of git to set a system config variable in the official
> system config directory; and then when testing with the test version of git,
> that value would not be seen because it was looking for the system config
> file in a different directory.
> 
> Jeff Hostetler (7):
>   trace2: refactor setting process starting time
>   trace2: add absolute elapsed time to start event
>   trace2: find exec-dir before trace2 initialization
>   trace2: use system config for default trace2 settings
>   trace2: report peak memory usage of the process
>   trace2: clarify UTC datetime formatting
>   trace2: make SIDs more unique
> 
>  Documentation/technical/api-trace2.txt   |  66 +++++++++---
>  Makefile                                 |   1 +
>  common-main.c                            |   8 +-
>  compat/mingw.c                           |   2 +
>  compat/win32/trace2_win32_process_info.c |  50 ++++++++-
>  t/t0210-trace2-normal.sh                 |  41 +++++++-
>  t/t0211-trace2-perf.sh                   |  53 ++++++++--
>  t/t0212-trace2-event.sh                  |  52 ++++++++-
>  trace2.c                                 |  21 +++-
>  trace2.h                                 |  43 ++++++--
>  trace2/tr2_cfg.c                         |   7 +-
>  trace2/tr2_dst.c                         |  24 ++---
>  trace2/tr2_dst.h                         |   3 +-
>  trace2/tr2_sid.c                         |  39 ++++++-
>  trace2/tr2_sysenv.c                      | 128 +++++++++++++++++++++++
>  trace2/tr2_sysenv.h                      |  36 +++++++
>  trace2/tr2_tbuf.c                        |  20 +++-
>  trace2/tr2_tbuf.h                        |   5 +-
>  trace2/tr2_tgt.h                         |   1 +
>  trace2/tr2_tgt_event.c                   |  53 +++++-----
>  trace2/tr2_tgt_normal.c                  |  19 ++--
>  trace2/tr2_tgt_perf.c                    |  23 ++--
>  trace2/tr2_tls.c                         |  38 ++++---
>  trace2/tr2_tls.h                         |   8 +-
>  24 files changed, 604 insertions(+), 137 deletions(-)
>  create mode 100644 trace2/tr2_sysenv.c
>  create mode 100644 trace2/tr2_sysenv.h
> 
> 
> base-commit: 041f5ea1cf987a4068ef5f39ba0a09be85952064
> Published-As: https://github.com/gitgitgadget/git/releases/tag/pr-169%2Fjeffhostetler%2Fcore-tr2-startup-and-sysenv-v2
> Fetch-It-Via: git fetch https://github.com/gitgitgadget/git pr-169/jeffhostetler/core-tr2-startup-and-sysenv-v2
> Pull-Request: https://github.com/gitgitgadget/git/pull/169

This series looks good to me, apart from the open question about
documentation. Thanks!

Reviewed-by: Josh Steadmon <steadmon@google.com>

^ permalink raw reply	[flat|nested] 68+ messages in thread

* Re: [PATCH v2 5/7] trace2: report peak memory usage of the process
  2019-03-29 22:16     ` Ævar Arnfjörð Bjarmason
@ 2019-04-01 21:05       ` Jeff Hostetler
  0 siblings, 0 replies; 68+ messages in thread
From: Jeff Hostetler @ 2019-04-01 21:05 UTC (permalink / raw)
  To: Ævar Arnfjörð Bjarmason, Jeff Hostetler via GitGitGadget
  Cc: git, peff, jrnieder, steadmon, Junio C Hamano, Jeff Hostetler



On 3/29/2019 6:16 PM, Ævar Arnfjörð Bjarmason wrote:
> 
> On Fri, Mar 29 2019, Jeff Hostetler via GitGitGadget wrote:
> 
>> From: Jeff Hostetler <jeffhost@microsoft.com>
>>
>> Teach Windows version of git to report peak memory usage
>> during exit() processing.
>>
>> Signed-off-by: Jeff Hostetler <jeffhost@microsoft.com>
>> ---
>>   common-main.c                            |  2 +-
>>   compat/win32/trace2_win32_process_info.c | 50 ++++++++++++++++++++++--
>>   trace2.c                                 |  2 +
>>   trace2.h                                 | 14 +++++--
>>   4 files changed, 60 insertions(+), 8 deletions(-)
>>
>> diff --git a/common-main.c b/common-main.c
>> index 299ca62a72..582a7b1886 100644
>> --- a/common-main.c
>> +++ b/common-main.c
>> @@ -41,7 +41,7 @@ int main(int argc, const char **argv)
>>
>>   	trace2_initialize();
>>   	trace2_cmd_start(argv);
>> -	trace2_collect_process_info();
>> +	trace2_collect_process_info(TRACE2_PROCESS_INFO_STARTUP);
>>
>>   	git_setup_gettext();
>>
>> diff --git a/compat/win32/trace2_win32_process_info.c b/compat/win32/trace2_win32_process_info.c
>> index 52bd62034b..2a514caed9 100644
>> --- a/compat/win32/trace2_win32_process_info.c
>> +++ b/compat/win32/trace2_win32_process_info.c
>> @@ -1,5 +1,6 @@
>>   #include "../../cache.h"
>>   #include "../../json-writer.h"
>> +#include "lazyload.h"
>>   #include <Psapi.h>
>>   #include <tlHelp32.h>
>>
>> @@ -137,11 +138,54 @@ static void get_is_being_debugged(void)
>>   				   "windows/debugger_present", 1);
>>   }
>>
>> -void trace2_collect_process_info(void)
>> +/*
>> + * Emit JSON data with the peak memory usage of the current process.
>> + */
>> +static void get_peak_memory_info(void)
>> +{
>> +	DECLARE_PROC_ADDR(psapi.dll, BOOL, GetProcessMemoryInfo,
>> +			  HANDLE, PPROCESS_MEMORY_COUNTERS, DWORD);
>> +
>> +	if (INIT_PROC_ADDR(GetProcessMemoryInfo)) {
>> +		PROCESS_MEMORY_COUNTERS pmc;
>> +
>> +		if (GetProcessMemoryInfo(GetCurrentProcess(), &pmc,
>> +					 sizeof(pmc))) {
>> +			struct json_writer jw = JSON_WRITER_INIT;
>> +
>> +			jw_object_begin(&jw, 0);
>> +
>> +#define KV(kv) #kv, (intmax_t)pmc.kv
>> +
>> +			jw_object_intmax(&jw, KV(PageFaultCount));
>> +			jw_object_intmax(&jw, KV(PeakWorkingSetSize));
>> +			jw_object_intmax(&jw, KV(PeakPagefileUsage));
>> +
>> +			jw_end(&jw);
>> +
>> +			trace2_data_json("process", the_repository,
>> +					 "windows/memory", &jw);
>> +			jw_release(&jw);
>> +		}
>> +	}
>> +}
>> +
>> +void trace2_collect_process_info(enum trace2_process_info_reason reason)
>>   {
>>   	if (!trace2_is_enabled())
>>   		return;
>>
>> -	get_is_being_debugged();
>> -	get_ancestry();
>> +	switch (reason) {
>> +	case TRACE2_PROCESS_INFO_STARTUP:
>> +		get_is_being_debugged();
>> +		get_ancestry();
>> +		return;
>> +
>> +	case TRACE2_PROCESS_INFO_EXIT:
>> +		get_peak_memory_info();
>> +		return;
>> +
>> +	default:
>> +		BUG("trace2_collect_process_info: unknown reason '%d'", reason);
>> +	}
>>   }
>> diff --git a/trace2.c b/trace2.c
>> index 490b3f071e..6baa65cdf9 100644
>> --- a/trace2.c
>> +++ b/trace2.c
>> @@ -213,6 +213,8 @@ int trace2_cmd_exit_fl(const char *file, int line, int code)
>>   	if (!trace2_enabled)
>>   		return code;
>>
>> +	trace2_collect_process_info(TRACE2_PROCESS_INFO_EXIT);
>> +
>>   	tr2main_exit_code = code;
>>
>>   	us_now = getnanotime() / 1000;
>> diff --git a/trace2.h b/trace2.h
>> index 894bfca7e0..888531eb08 100644
>> --- a/trace2.h
>> +++ b/trace2.h
>> @@ -391,13 +391,19 @@ void trace2_printf(const char *fmt, ...);
>>    * Optional platform-specific code to dump information about the
>>    * current and any parent process(es).  This is intended to allow
>>    * post-processors to know who spawned this git instance and anything
>> - * else the platform may be able to tell us about the current process.
>> + * else that the platform may be able to tell us about the current process.
>>    */
>> +
>> +enum trace2_process_info_reason {
>> +	TRACE2_PROCESS_INFO_STARTUP,
>> +	TRACE2_PROCESS_INFO_EXIT,
>> +};
>> +
>>   #if defined(GIT_WINDOWS_NATIVE)
>> -void trace2_collect_process_info(void);
>> +void trace2_collect_process_info(enum trace2_process_info_reason reason);
>>   #else
>> -#define trace2_collect_process_info() \
>> -	do {                          \
>> +#define trace2_collect_process_info(reason) \
>> +	do {                                \
>>   	} while (0)
>>   #endif
> 
> FWIW this is the "VmPeak" line in /proc/$$/status on Linux. I don't know
> if we can/should parse that in practice (I've been bitten in the past by
> things in /proc having high cost on some kernel versions in the past,
> notably smaps).
> 

Thanks,

Yeah, I've avoided adding the corresponding platform-specific changes
in for non-Windows versions because I didn't want to venture off into
the weeds and introduce a perf or functional problem (for something
that I'm not going to make use of in the short term).  Whereas, we're
seeing occasional perf problems with our Windows users on the OS repo
where some (yet to be determined) commands will just go out to lunch.

I suspect we'll have similar problems with out Mac users in the near
future, but I didn't want to jump in there just yet.

Jeff




^ permalink raw reply	[flat|nested] 68+ messages in thread

* Re: [PATCH v2 4/7] trace2: use system config for default trace2 settings
  2019-04-01 21:00     ` Josh Steadmon
@ 2019-04-01 21:06       ` Jeff Hostetler
  2019-04-03  0:01       ` Jonathan Nieder
  1 sibling, 0 replies; 68+ messages in thread
From: Jeff Hostetler @ 2019-04-01 21:06 UTC (permalink / raw)
  To: Josh Steadmon, Jeff Hostetler via GitGitGadget, git, gitster,
	peff, jrnieder, avarab, Jeff Hostetler



On 4/1/2019 5:00 PM, Josh Steadmon wrote:
> On 2019.03.29 10:04, Jeff Hostetler via GitGitGadget wrote:
> [...]
>> diff --git a/Documentation/technical/api-trace2.txt b/Documentation/technical/api-trace2.txt
>> index baaa1153bb..13ca595c69 100644
>> --- a/Documentation/technical/api-trace2.txt
>> +++ b/Documentation/technical/api-trace2.txt
>> @@ -117,6 +117,37 @@ values are recognized.
>>   Socket type can be either `stream` or `dgram`.  If the socket type is
>>   omitted, Git will try both.
>>   
>> +== Trace2 Settings in System Config
>> +
>> +Trace2 also reads configuration information from the system config.
>> +This is intended to help adminstrators to gather system-wide Git
>> +performance data.
>> +
>> +Trace2 only reads the system configuration, it does not read global,
>> +local, worktree, or `-c` config settings.
>> +
>> +Trace2 will try to load the following system configuration settings
>> +and then read the corresponding environment variables at startup.
>> +
>> +....
>> +---------------------------------------------------
>> +trace2.normalTarget          GIT_TR2
>> +trace2.normalBrief           GIT_TR2_BRIEF
>> +
>> +trace2.perfTarget            GIT_TR2_PERF
>> +trace2.perfBrief             GIT_TR2_PERF_BRIEF
>> +
>> +trace2.eventTarget           GIT_TR2_EVENT
>> +trace2.eventBrief            GIT_TR2_EVENT_BRIEF
>> +trace2.eventNesting          GIT_TR2_EVENT_NESTING
>> +
>> +trace2.configParams          GIT_TR2_CONFIG_PARAMS
>> +
>> +trace2.destinationDebug      GIT_TR2_DST_DEBUG
>> +---------------------------------------------------
>> +....
>> +
>> +
> 
> A question for the list: should these new config vars also be documented
> in the git-config manpage, or is it better to keep these separate since
> they are only read from the system config?
> 

I wasn't sure either, so I just kept them in the trace2 api doc for now.
Jeff

^ permalink raw reply	[flat|nested] 68+ messages in thread

* Re: [PATCH v2 7/7] trace2: make SIDs more unique
  2019-03-29 22:12     ` Ævar Arnfjörð Bjarmason
@ 2019-04-01 21:16       ` Jeff Hostetler
  0 siblings, 0 replies; 68+ messages in thread
From: Jeff Hostetler @ 2019-04-01 21:16 UTC (permalink / raw)
  To: Ævar Arnfjörð Bjarmason, Jeff Hostetler via GitGitGadget
  Cc: git, peff, jrnieder, steadmon, Junio C Hamano, Jeff Hostetler



On 3/29/2019 6:12 PM, Ævar Arnfjörð Bjarmason wrote:
> 
> On Fri, Mar 29 2019, Jeff Hostetler via GitGitGadget wrote:
> 
>> From: Jeff Hostetler <jeffhost@microsoft.com>
>>
>> Update SID component construction to use the current UTC datetime
>> and a portion of the SHA1 of the hostname.
>>
>> Use an simplified date/time format to make it easier to use the
>> SID component as a logfile filename.
>> [...]
>> +static void tr2_sid_append_my_sid_component(void)
>> +{
>> +	const struct git_hash_algo *algo = &hash_algos[GIT_HASH_SHA1];
>> +	struct tr2_tbuf tb_now;
>> +	git_hash_ctx ctx;
>> +	unsigned char hash[GIT_MAX_RAWSZ + 1];
>> +	char hex[GIT_MAX_HEXSZ + 1];
>> +	char hostname[HOST_NAME_MAX + 1];
>> +
>> +	tr2_tbuf_utc_datetime_for_filename(&tb_now);
>> +	strbuf_addstr(&tr2sid_buf, tb_now.buf);
>> +	strbuf_addch(&tr2sid_buf, '-');
>> +
>> +	if (xgethostname(hostname, sizeof(hostname)))
>> +		xsnprintf(hostname, sizeof(hostname), "localhost");
>> +
>> +	algo->init_fn(&ctx);
>> +	algo->update_fn(&ctx, hostname, strlen(hostname));
>> +	algo->final_fn(hash, &ctx);
>> +	hash_to_hex_algop_r(hex, hash, algo);
>> +	strbuf_add(&tr2sid_buf, hex, 8);
>> +
>> +	strbuf_addch(&tr2sid_buf, '-');
>> +	strbuf_addf(&tr2sid_buf, "%06"PRIuMAX, (uintmax_t)getpid());
>> +}
>> +
> 
> Thanks for turning my shitty half-formed idea into a patch :)
> 
> I wrote this on top to bikeshed this a bit further, wonder what you
> think:
> https://github.com/gitgitgadget/git/compare/pr-169/jeffhostetler/core-tr2-startup-and-sysenv-v2...avar:pr-169/jeffhostetler/core-tr2-startup-and-sysenv-v2
> 
> So e.g.:
> 
>      Before: 20190329-220413-446441-c2f5b994-018702
>      After:  20190329T220431.244562Z-Hc2f5b994-P19812F
> 
> I.e:
> 
>   * Using <date>T<time> as is ISO 8601 convention/easier to read
> 
>   * <dateime>.<microseconds>Z, so seperating with "." to indicate it's
>     the same value + add "Z" for "it's UTC". I'm least sure about the
>     ".". Is that going to cause issues on Windows these days (the rest
>     being the "extension"...).

I had a version that did just that.  I checked the various ISO and RFCs
and it seems like the fractional seconds is usually allowed between the
whole seconds and the "Z".

I've not seen any problems with that format.

I think I got spooked by your original suggestion to put the fraction in
a term after the whole "<date>T<time>Z" term.

I'll convert it back to match your suggestion.

> 
>   * I changed the hostname discovery so if gethostbyname() fails we'll
>     print "-H00000000-" for that part, instead of "-H<first 8 chars of
>     the sha1 for 'localhost'>-". Also prefix with "H" for "Host".

I like that.

> 
>   * Wrap pids to 0xffff, prefix with "P" (Pid)" and trail with either "F"
>     = Full or "W" = Wrapped (not the real PID).

I could see the "P".  I'm not sure about the hex -- I sometimes want to
do a "ps" or watch the processes go by in TaskManager and friends and
they all print the pid in decimal.  But it's not that big a deal.

> 
>   * I didn't add "T<datetime>" like "H" and "P" for the rest, since it's
>     obvious what sort of value it is.
> 
> Maybe this is going a bit overboard, but I think it's easier to read at
> a glance for humans, and since it's meant to be opaque to machines
> anyway and the length is simliar enough not to matter I figure it's
> worth it.
> 

I'll re-roll.
Thanks
Jeff


^ permalink raw reply	[flat|nested] 68+ messages in thread

* Re: [PATCH v2 4/7] trace2: use system config for default trace2 settings
  2019-03-29 17:04   ` [PATCH v2 4/7] trace2: use system config for default trace2 settings Jeff Hostetler via GitGitGadget
  2019-04-01 21:00     ` Josh Steadmon
@ 2019-04-03  0:00     ` Jonathan Nieder
  2019-04-09 15:58       ` Jeff Hostetler
  1 sibling, 1 reply; 68+ messages in thread
From: Jonathan Nieder @ 2019-04-03  0:00 UTC (permalink / raw)
  To: Jeff Hostetler via GitGitGadget
  Cc: git, gitster, peff, steadmon, avarab, Jeff Hostetler

Hi,

Jeff Hostetler via GitGitGadget wrote:

> Teach git to read the system config (usually "/etc/gitconfig") for
> default Trace2 settings.  This allows system-wide Trace2 settings to
> be installed and inherited to make it easier to manage a collection of
> systems.

Yay!  Thanks for writing this, and sorry for the slow review.

[...]
> Only the system config file is used.  Trace2 config values are ignored
> in local, global, and other config files.  Likewise, the "-c" command
> line arguments are ignored for Trace2 values.  These limits are for
> performance reasons.

Can you say a bit more about this?  If I'm willing to pay the
performance cost, is there a way for me to turn on respecting other
config files?  What is that performance cost?

[...]
> --- a/Documentation/technical/api-trace2.txt
> +++ b/Documentation/technical/api-trace2.txt
> @@ -117,6 +117,37 @@ values are recognized.
>  Socket type can be either `stream` or `dgram`.  If the socket type is
>  omitted, Git will try both.
>  
> +== Trace2 Settings in System Config
> +
> +Trace2 also reads configuration information from the system config.
> +This is intended to help adminstrators to gather system-wide Git
> +performance data.
> +
> +Trace2 only reads the system configuration, it does not read global,
> +local, worktree, or `-c` config settings.

An additional limitation is that this doesn't appear to support
include.* directives.  Intended?

[...]
> --- a/t/t0210-trace2-normal.sh
> +++ b/t/t0210-trace2-normal.sh
[...]
> +MOCK=./mock_system_config
> +
> +test_expect_success 'setup mocked /etc/gitconfig' '
> +	git config --file $MOCK trace2.normalTarget "$(pwd)/trace.normal" &&
> +	git config --file $MOCK trace2.normalBrief 1
> +'
> +
> +test_expect_success 'using mock, normal stream, return code 0' '
> +	test_when_finished "rm trace.normal actual expect" &&
> +	GIT_TEST_TR2_SYSTEM_CONFIG="$MOCK" test-tool trace2 001return 0 &&

Tests run with GIT_CONFIG_NOSYSTEM=1 to protect themselves from any
system config the user has.

So this would be easier to test if we can use user-level config for
it.

[...]
> --- /dev/null
> +++ b/trace2/tr2_sysenv.c
> @@ -0,0 +1,128 @@
> +#include "cache.h"
> +#include "config.h"
> +#include "dir.h"
> +#include "tr2_sysenv.h"
> +
> +/*
> + * Each entry represents a trace2 setting.
> + * See Documentation/technical/api-trace2.txt
> + */
> +struct tr2_sysenv_entry {
> +	const char *env_var_name;
> +	const char *git_config_name;
> +
> +	char *value;
> +	unsigned int getenv_called : 1;
> +};
> +
> +/*
> + * This table must match "enum tr2_sysenv_variable" in tr2_sysenv.h.

Can we deduplicate to avoid the need to match?

Perhaps using C99 array initializers would help:

	[TR2_SYSENV_CFG_PARAM] = { ... },

[...]
> +/*
> + * Load Trace2 settings from the system config (usually "/etc/gitconfig"
> + * unless we were built with a runtime-prefix).  These are intended to
> + * define the default values for Trace2 as requested by the administrator.
> + */
> +void tr2_sysenv_load(void)
> +{
> +	const char *system_config_pathname;
> +	const char *test_pathname;
> +
> +	system_config_pathname = git_etc_gitconfig();
> +
> +	test_pathname = getenv("GIT_TEST_TR2_SYSTEM_CONFIG");
> +	if (test_pathname) {
> +		if (!*test_pathname || !strcmp(test_pathname, "0"))
> +			return; /* disable use of system config */
> +
> +		/* mock it with given test file */
> +		system_config_pathname = test_pathname;
> +	}
> +
> +	if (file_exists(system_config_pathname))
> +		git_config_from_file(tr2_sysenv_cb, system_config_pathname,
> +				     NULL);

This duplicates functionality from config.c and misses some features
along the way (e.g. support for include.*).

Would read_early_config work?  If we want a variant that doesn't
discover_git_directory, we can change that function to handle it.

For our needs at Google, it would be very helpful to have support for
include.* and reading settings from at least $HOME/.gitconfig in
addition to /etc/gitconfig (even better if it supports per-repo config
as well).  I believe it would simplify the code and tests, too.  If
there's anything I can to help, please don't hesitate to ask.

Thanks,
Jonathan

^ permalink raw reply	[flat|nested] 68+ messages in thread

* Re: [PATCH v2 4/7] trace2: use system config for default trace2 settings
  2019-04-01 21:00     ` Josh Steadmon
  2019-04-01 21:06       ` Jeff Hostetler
@ 2019-04-03  0:01       ` Jonathan Nieder
  1 sibling, 0 replies; 68+ messages in thread
From: Jonathan Nieder @ 2019-04-03  0:01 UTC (permalink / raw)
  To: Josh Steadmon
  Cc: Jeff Hostetler via GitGitGadget, git, gitster, peff, avarab,
	Jeff Hostetler

Josh Steadmon wrote:

> A question for the list: should these new config vars also be documented
> in the git-config manpage, or is it better to keep these separate since
> they are only read from the system config?

Yes, they should be in the git-config manpage.

*If* they are read only from the system config, the documentation
there should say so.

Thanks,
Jonathan

^ permalink raw reply	[flat|nested] 68+ messages in thread

* Re: [PATCH v2 4/7] trace2: use system config for default trace2 settings
  2019-04-03  0:00     ` Jonathan Nieder
@ 2019-04-09 15:58       ` Jeff Hostetler
  0 siblings, 0 replies; 68+ messages in thread
From: Jeff Hostetler @ 2019-04-09 15:58 UTC (permalink / raw)
  To: Jonathan Nieder, Jeff Hostetler via GitGitGadget
  Cc: git, gitster, peff, steadmon, avarab, Jeff Hostetler



On 4/2/2019 8:00 PM, Jonathan Nieder wrote:
> Hi,
> 
> Jeff Hostetler via GitGitGadget wrote:
> 
>> Teach git to read the system config (usually "/etc/gitconfig") for
>> default Trace2 settings.  This allows system-wide Trace2 settings to
>> be installed and inherited to make it easier to manage a collection of
>> systems.
> 
> Yay!  Thanks for writing this, and sorry for the slow review.
> 
> [...]
>> Only the system config file is used.  Trace2 config values are ignored
>> in local, global, and other config files.  Likewise, the "-c" command
>> line arguments are ignored for Trace2 values.  These limits are for
>> performance reasons.
> 
> Can you say a bit more about this?  If I'm willing to pay the
> performance cost, is there a way for me to turn on respecting other
> config files?  What is that performance cost?

Several thoughts here.  Some are performance-related and some are
startup chicken-n-egg problems.  I tried to add trace2 to the code
base in the least disruptive way possible and hopefully with minimal
side-effects on existing behaviors.  And also minimum impact on overall
performance when not in use.

So, with that in mind:

[] Trace2 should be initialized as early as and lightly as possible
    so that timers are started and it can capture events from other
    startup activities.  And so that we can tell as early as possible
    if trace2 should NOT be enabled and short-cut those calls and not
    waste time collecting unnecessary data.

[] Trace2 is initialized by calls from common-main.c:main().  This
    happens before cmd_main() is called, so we are very early in the
    startup process and very few things have been initialized.  For
    example, I had to let git_resolve_executable_dir() run so that
    we could find the location of the system config, but that's about
    it.  We have not even initialized "the_repository" yet.

[] WRT "-c var=val", this is processed by git.c:handle_options() and
    called from git.c:cmd_main() and git.c:handle_alias().  So the "-c"
    args won't be respected until after that point.

    Adding trace2 initialization after that point is a bit of a mess.
    Teaching trace2 to scan the argv for "-c" is just duplicating effort.
    And moving the "-c" processing earlier in the startup, changes the
    behavior of the "git-*" commands (which don't currently recognize
    the "-c" option).

    So that's why I'm suggesting we not respect "-c" for this.

[] By initializing trace2 inside main() we guarantee that it will get
    started.  If we wait to initialize it until after handle_options()
    returns, we miss events for commands that it handles itself (such
    as "git --exec-path" where it just prints and exits or syntax errors
    where it directly calls usage() and exits).

[] WRT to per-repo config values:

    In common-main.c:main() we have not yet discovered the .git dir,
    so repo-local config files are questionable at a very early point
    in the process startup.  Again, it comes down to whether we wait
    for gitdir discovery (and whatever file system scanning, --gitdir,
    or -C processing is required) before deciding whether to start
    trace2 or not.

    Also, per-repo trace2 config settings aren't available at the time
    of the clone, so just relying on them will leave our telemetry
    incomplete.  It's better to have a system (or maybe a user) setting
    and not a per-repo setting.

    Longer term, with submodules and plans to support them in-proc rather
    than via sub-processes, I don't think there should be any expectation
    that trace2 settings would adapt during recursive operations.  So for
    example, a top-level command might see different trace2 settings than
    a command run inside a submodule.  If submodule operations become
    in-proc, then to maintain that expected behavior we'd need to have
    per-repo trace2 settings.  (Granted, not impossible, but by saying no
    to that now, we can eliminate a possible pain point in the future.)

[] i'll add more on this topic at the bottom of this note in response to
    your per-user and includes questions.


> [...]
>> --- a/Documentation/technical/api-trace2.txt
>> +++ b/Documentation/technical/api-trace2.txt
>> @@ -117,6 +117,37 @@ values are recognized.
>>   Socket type can be either `stream` or `dgram`.  If the socket type is
>>   omitted, Git will try both.
>>   
>> +== Trace2 Settings in System Config
>> +
>> +Trace2 also reads configuration information from the system config.
>> +This is intended to help adminstrators to gather system-wide Git
>> +performance data.
>> +
>> +Trace2 only reads the system configuration, it does not read global,
>> +local, worktree, or `-c` config settings.
> 
> An additional limitation is that this doesn't appear to support
> include.* directives.  Intended?

I didn't specifically intend to support or not-support include files
here.  Frankly, the complexity of the config code makes my eyes bleed.
I'll investigate adding it.


> 
> [...]
>> --- a/t/t0210-trace2-normal.sh
>> +++ b/t/t0210-trace2-normal.sh
> [...]
>> +MOCK=./mock_system_config
>> +
>> +test_expect_success 'setup mocked /etc/gitconfig' '
>> +	git config --file $MOCK trace2.normalTarget "$(pwd)/trace.normal" &&
>> +	git config --file $MOCK trace2.normalBrief 1
>> +'
>> +
>> +test_expect_success 'using mock, normal stream, return code 0' '
>> +	test_when_finished "rm trace.normal actual expect" &&
>> +	GIT_TEST_TR2_SYSTEM_CONFIG="$MOCK" test-tool trace2 001return 0 &&
> 
> Tests run with GIT_CONFIG_NOSYSTEM=1 to protect themselves from any
> system config the user has.

Thanks for the pointer.  I'll update the tr2_sysenv_load() to check
git_system_config() before trying to use the system config file.

> 
> So this would be easier to test if we can use user-level config for
> it.

I suppose.  I think it just moves the testing problem to a trick using
$HOME, right?  But it does get rid of that GIT_TEST_TR2_SYSTEM_CONFIG
symbol, so yeah a net win.  I'll investigate.  Thanks.


> [...]
>> --- /dev/null
>> +++ b/trace2/tr2_sysenv.c
>> @@ -0,0 +1,128 @@
>> +#include "cache.h"
>> +#include "config.h"
>> +#include "dir.h"
>> +#include "tr2_sysenv.h"
>> +
>> +/*
>> + * Each entry represents a trace2 setting.
>> + * See Documentation/technical/api-trace2.txt
>> + */
>> +struct tr2_sysenv_entry {
>> +	const char *env_var_name;
>> +	const char *git_config_name;
>> +
>> +	char *value;
>> +	unsigned int getenv_called : 1;
>> +};
>> +
>> +/*
>> + * This table must match "enum tr2_sysenv_variable" in tr2_sysenv.h.
> 
> Can we deduplicate to avoid the need to match?
> 
> Perhaps using C99 array initializers would help:
> 
> 	[TR2_SYSENV_CFG_PARAM] = { ... },

Cool.  I hadn't seen that syntax before.

> 
> [...]
>> +/*
>> + * Load Trace2 settings from the system config (usually "/etc/gitconfig"
>> + * unless we were built with a runtime-prefix).  These are intended to
>> + * define the default values for Trace2 as requested by the administrator.
>> + */
>> +void tr2_sysenv_load(void)
>> +{
>> +	const char *system_config_pathname;
>> +	const char *test_pathname;
>> +
>> +	system_config_pathname = git_etc_gitconfig();
>> +
>> +	test_pathname = getenv("GIT_TEST_TR2_SYSTEM_CONFIG");
>> +	if (test_pathname) {
>> +		if (!*test_pathname || !strcmp(test_pathname, "0"))
>> +			return; /* disable use of system config */
>> +
>> +		/* mock it with given test file */
>> +		system_config_pathname = test_pathname;
>> +	}
>> +
>> +	if (file_exists(system_config_pathname))
>> +		git_config_from_file(tr2_sysenv_cb, system_config_pathname,
>> +				     NULL);
> 
> This duplicates functionality from config.c and misses some features
> along the way (e.g. support for include.*).
> 
> Would read_early_config work?  If we want a variant that doesn't
> discover_git_directory, we can change that function to handle it.
> 
> For our needs at Google, it would be very helpful to have support for
> include.* and reading settings from at least $HOME/.gitconfig in
> addition to /etc/gitconfig (even better if it supports per-repo config
> as well).  I believe it would simplify the code and tests, too.  If
> there's anything I can to help, please don't hesitate to ask.

read_early_config() might work, but it is pretty heavy and doesn't
address my above comments.

Perhaps a compromise would be to have it read just the system and
user config files (w/ includes turned on).  It shouldn't take too
much time and it shouldn't have the startup-order dependencies, I
think.

Thoughts??

> 
> Thanks,
> Jonathan
> 

Thanks,
Jeff

^ permalink raw reply	[flat|nested] 68+ messages in thread

* [PATCH v3 00/10] trace2: load trace2 settings from system config
  2019-03-29 17:04 ` [PATCH v2 0/7] trace2: load trace2 settings from system config Jeff Hostetler via GitGitGadget
                     ` (7 preceding siblings ...)
  2019-04-01 21:02   ` [PATCH v2 0/7] trace2: load trace2 settings from system config Josh Steadmon
@ 2019-04-11 15:18   ` " Jeff Hostetler via GitGitGadget
  2019-04-11 15:18     ` [PATCH v3 01/10] config: initialize opts structure in repo_read_config() Jeff Hostetler via GitGitGadget
                       ` (11 more replies)
  8 siblings, 12 replies; 68+ messages in thread
From: Jeff Hostetler via GitGitGadget @ 2019-04-11 15:18 UTC (permalink / raw)
  To: git; +Cc: gitster, peff, jrnieder, steadmon, avarab, Junio C Hamano

Here is version 3.
[] It incorporates Ævar's suggestions WRT the format and uniqueness of the
SID. [] It now reads both system and global config for trace2 settings and
handles includes as Jonathan suggested.

I added a read_very_early_config() function that is similar to 
read_early_config()but omits repo local, worktree, and -c command line
settings. This felt like a little bit of a hack, but it made the intent
clear. And it avoided asserting the various global variables were in a
certain known state before calling the read_early_config().

In doing so, I uncovered an uninitialized opts variable in
read_repo_config(). The first patch in this series addresses it in
isolation. As the commit message suggests, this went undetected because opts 
variable doesn't get passed all the way down, but I'm not familiar enough
with that code to know whether that's an accident or by design. Callers of 
config_with_options() all setopts.respect_includes and that changes the args
that config_with_options()passes to the functions that it calls. What makes
this a little more troubling is theopts.event_fn field added in
8032cc4462b8af268fe457c2a0431473334dfd18 that might not be initialized.
Again, I'm not familiar enough with this code and the actually observable
control flows thru it to know if that could cause an issue.

Jeff Hostetler (10):
  config: initialize opts structure in repo_read_config()
  trace2: refactor setting process starting time
  trace2: add absolute elapsed time to start event
  trace2: find exec-dir before trace2 initialization
  config: add read_very_early_config()
  trace2: use system/global config for default trace2 settings
  trace2: report peak memory usage of the process
  trace2: clarify UTC datetime formatting
  trace2: make SIDs more unique
  trace2: update docs to describe system/global config settings

 Documentation/config.txt                 |   2 +
 Documentation/config/trace2.txt          |  56 ++++++++
 Documentation/technical/api-trace2.txt   | 176 +++++++++++++----------
 Documentation/trace2-target-values.txt   |  10 ++
 Makefile                                 |   1 +
 common-main.c                            |   8 +-
 compat/mingw.c                           |   2 +
 compat/win32/trace2_win32_process_info.c |  50 ++++++-
 config.c                                 |  27 +++-
 config.h                                 |   4 +
 t/t0210-trace2-normal.sh                 |  49 ++++++-
 t/t0211-trace2-perf.sh                   |  43 ++++--
 t/t0212-trace2-event.sh                  |  42 +++++-
 trace2.c                                 |  21 ++-
 trace2.h                                 |  43 ++++--
 trace2/tr2_cfg.c                         |   7 +-
 trace2/tr2_dst.c                         |  24 ++--
 trace2/tr2_dst.h                         |   3 +-
 trace2/tr2_sid.c                         |  55 ++++++-
 trace2/tr2_sysenv.c                      | 127 ++++++++++++++++
 trace2/tr2_sysenv.h                      |  36 +++++
 trace2/tr2_tbuf.c                        |  20 ++-
 trace2/tr2_tbuf.h                        |   5 +-
 trace2/tr2_tgt.h                         |   1 +
 trace2/tr2_tgt_event.c                   |  53 +++----
 trace2/tr2_tgt_normal.c                  |  19 +--
 trace2/tr2_tgt_perf.c                    |  23 +--
 trace2/tr2_tls.c                         |  38 +++--
 trace2/tr2_tls.h                         |   8 +-
 29 files changed, 750 insertions(+), 203 deletions(-)
 create mode 100644 Documentation/config/trace2.txt
 create mode 100644 Documentation/trace2-target-values.txt
 create mode 100644 trace2/tr2_sysenv.c
 create mode 100644 trace2/tr2_sysenv.h


base-commit: 041f5ea1cf987a4068ef5f39ba0a09be85952064
Published-As: https://github.com/gitgitgadget/git/releases/tag/pr-169%2Fjeffhostetler%2Fcore-tr2-startup-and-sysenv-v3
Fetch-It-Via: git fetch https://github.com/gitgitgadget/git pr-169/jeffhostetler/core-tr2-startup-and-sysenv-v3
Pull-Request: https://github.com/gitgitgadget/git/pull/169

Range-diff vs v2:

  -:  ---------- >  1:  ea8c199f91 config: initialize opts structure in repo_read_config()
  1:  7f1a347322 =  2:  3dbcfc6a8d trace2: refactor setting process starting time
  2:  c15f783c26 =  3:  8b00025af5 trace2: add absolute elapsed time to start event
  3:  d4023acde7 =  4:  c3c5f6a96b trace2: find exec-dir before trace2 initialization
  -:  ---------- >  5:  d15be7b63a config: add read_very_early_config()
  4:  d048f3ffb8 !  6:  c085a482dd trace2: use system config for default trace2 settings
     @@ -1,8 +1,8 @@
      Author: Jeff Hostetler <jeffhost@microsoft.com>
      
     -    trace2: use system config for default trace2 settings
     +    trace2: use system/global config for default trace2 settings
      
     -    Teach git to read the system config (usually "/etc/gitconfig") for
     +    Teach git to read the system and global config files for
          default Trace2 settings.  This allows system-wide Trace2 settings to
          be installed and inherited to make it easier to manage a collection of
          systems.
     @@ -10,10 +10,9 @@
          The original GIT_TR2* environment variables are loaded afterwards and
          can be used to override the system settings.
      
     -    Only the system config file is used.  Trace2 config values are ignored
     -    in local, global, and other config files.  Likewise, the "-c" command
     -    line arguments are ignored for Trace2 values.  These limits are for
     -    performance reasons.
     +    Only the system and global config files are used.  Repo and worktree
     +    local config files are ignored.  Likewise, the "-c" command line
     +    arguments are also ignored.  These limits are for performance reasons.
      
          (1) For users not using Trace2, there should be minimal overhead to
          detect that Trace2 is not enabled.  In particular, Trace2 should not
     @@ -24,54 +23,8 @@
          git process initialization (which involves discovering the .git directory
          and reading a hierarchy of config files).
      
     -    Added the GIT_TEST_TR2_SYSTEM_CONFIG environment variable for testing
     -    purposes to specify the pathname of a fake "system" config or disable
     -    use of the system config.
     -
          Signed-off-by: Jeff Hostetler <jeffhost@microsoft.com>
      
     - diff --git a/Documentation/technical/api-trace2.txt b/Documentation/technical/api-trace2.txt
     - --- a/Documentation/technical/api-trace2.txt
     - +++ b/Documentation/technical/api-trace2.txt
     -@@
     - Socket type can be either `stream` or `dgram`.  If the socket type is
     - omitted, Git will try both.
     - 
     -+== Trace2 Settings in System Config
     -+
     -+Trace2 also reads configuration information from the system config.
     -+This is intended to help adminstrators to gather system-wide Git
     -+performance data.
     -+
     -+Trace2 only reads the system configuration, it does not read global,
     -+local, worktree, or `-c` config settings.
     -+
     -+Trace2 will try to load the following system configuration settings
     -+and then read the corresponding environment variables at startup.
     -+
     -+....
     -+---------------------------------------------------
     -+trace2.normalTarget          GIT_TR2
     -+trace2.normalBrief           GIT_TR2_BRIEF
     -+
     -+trace2.perfTarget            GIT_TR2_PERF
     -+trace2.perfBrief             GIT_TR2_PERF_BRIEF
     -+
     -+trace2.eventTarget           GIT_TR2_EVENT
     -+trace2.eventBrief            GIT_TR2_EVENT_BRIEF
     -+trace2.eventNesting          GIT_TR2_EVENT_NESTING
     -+
     -+trace2.configParams          GIT_TR2_CONFIG_PARAMS
     -+
     -+trace2.destinationDebug      GIT_TR2_DST_DEBUG
     -+---------------------------------------------------
     -+....
     -+
     -+
     - == Trace2 API
     - 
     - All public Trace2 functions and macros are defined in `trace2.h` and
     -
       diff --git a/Makefile b/Makefile
       --- a/Makefile
       +++ b/Makefile
     @@ -90,10 +43,6 @@
      @@
       #!/bin/sh
       
     -+# Disable loading of Trace2 settings from the system config
     -+# (usually "/etc/gitconfig") to eliminate system dependencies.
     -+GIT_TEST_TR2_SYSTEM_CONFIG=0 && export GIT_TEST_TR2_SYSTEM_CONFIG
     -+
      +# Turn off any inherited trace2 settings for this test.
      +unset GIT_TR2 GIT_TR2_PERF GIT_TR2_EVENT
      +unset GIT_TR2_BRIEF
     @@ -118,22 +67,34 @@
       	test_cmp expect actual
       '
       
     -+# Now test using system config by using a mocked up config file
     -+# rather than inheriting "/etc/gitconfig".  Here we do not use
     -+# GIT_TR2* environment variables.
     -+
      +unset GIT_TR2_BRIEF
      +
     -+MOCK=./mock_system_config
     ++# Now test without environment variables and get all Trace2 settings
     ++# from the global config.
      +
     -+test_expect_success 'setup mocked /etc/gitconfig' '
     -+	git config --file $MOCK trace2.normalTarget "$(pwd)/trace.normal" &&
     -+	git config --file $MOCK trace2.normalBrief 1
     ++test_expect_success 'using global config, normal stream, return code 0' '
     ++	test_when_finished "rm trace.normal actual expect" &&
     ++	test_config_global trace2.normalBrief 1 &&
     ++	test_config_global trace2.normalTarget "$(pwd)/trace.normal" &&
     ++	test-tool trace2 001return 0 &&
     ++	perl "$TEST_DIRECTORY/t0210/scrub_normal.perl" <trace.normal >actual &&
     ++	cat >expect <<-EOF &&
     ++		version $V
     ++		start _EXE_ trace2 001return 0
     ++		cmd_name trace2 (trace2)
     ++		exit elapsed:_TIME_ code:0
     ++		atexit elapsed:_TIME_ code:0
     ++	EOF
     ++	test_cmp expect actual
      +'
      +
     -+test_expect_success 'using mock, normal stream, return code 0' '
     -+	test_when_finished "rm trace.normal actual expect" &&
     -+	GIT_TEST_TR2_SYSTEM_CONFIG="$MOCK" test-tool trace2 001return 0 &&
     ++test_expect_success 'using global config with include' '
     ++	test_when_finished "rm trace.normal actual expect real.gitconfig" &&
     ++	test_config_global trace2.normalBrief 1 &&
     ++	test_config_global trace2.normalTarget "$(pwd)/trace.normal" &&
     ++	mv "$(pwd)/.gitconfig" "$(pwd)/real.gitconfig" &&
     ++	test_config_global include.path "$(pwd)/real.gitconfig" &&
     ++	test-tool trace2 001return 0 &&
      +	perl "$TEST_DIRECTORY/t0210/scrub_normal.perl" <trace.normal >actual &&
      +	cat >expect <<-EOF &&
      +		version $V
     @@ -153,10 +114,6 @@
      @@
       #!/bin/sh
       
     -+# Disable loading of Trace2 settings from the system config
     -+# (usually "/etc/gitconfig") to eliminate system dependencies.
     -+GIT_TEST_TR2_SYSTEM_CONFIG=0 && export GIT_TEST_TR2_SYSTEM_CONFIG
     -+
      +# Turn off any inherited trace2 settings for this test.
      +unset GIT_TR2 GIT_TR2_PERF GIT_TR2_EVENT
      +unset GIT_TR2_PERF_BRIEF
     @@ -181,22 +138,16 @@
       	test_cmp expect actual
       '
       
     -+# Now test using system config by using a mocked up config file
     -+# rather than inheriting "/etc/gitconfig".  Here we do not use
     -+# GIT_TR2* environment variables.
     -+
      +unset GIT_TR2_PERF_BRIEF
      +
     -+MOCK=./mock_system_config
     -+
     -+test_expect_success 'setup mocked /etc/gitconfig' '
     -+	git config --file $MOCK trace2.perfTarget "$(pwd)/trace.perf" &&
     -+	git config --file $MOCK trace2.perfBrief 1
     -+'
     ++# Now test without environment variables and get all Trace2 settings
     ++# from the global config.
      +
     -+test_expect_success 'using mock, perf stream, return code 0' '
     ++test_expect_success 'using global config, perf stream, return code 0' '
      +	test_when_finished "rm trace.perf actual expect" &&
     -+	GIT_TEST_TR2_SYSTEM_CONFIG="$MOCK" test-tool trace2 001return 0 &&
     ++	test_config_global trace2.perfBrief 1 &&
     ++	test_config_global trace2.perfTarget "$(pwd)/trace.perf" &&
     ++	test-tool trace2 001return 0 &&
      +	perl "$TEST_DIRECTORY/t0211/scrub_perf.perl" <trace.perf >actual &&
      +	cat >expect <<-EOF &&
      +		d0|main|version|||||$V
     @@ -216,10 +167,6 @@
      @@
       #!/bin/sh
       
     -+# Disable loading of Trace2 settings from the system config
     -+# (usually "/etc/gitconfig") to eliminate system dependencies.
     -+GIT_TEST_TR2_SYSTEM_CONFIG=0 && export GIT_TEST_TR2_SYSTEM_CONFIG
     -+
      +# Turn off any inherited trace2 settings for this test.
      +unset GIT_TR2 GIT_TR2_PERF GIT_TR2_EVENT
      +unset GIT_TR2_BARE
     @@ -244,19 +191,13 @@
       	test_cmp expect actual
       '
       
     -+# Now test using system config by using a mocked up config file
     -+# rather than inheriting "/etc/gitconfig".  Here we do not use
     -+# GIT_TR2* environment variables.
     -+
     -+MOCK=./mock_system_config
     ++# Now test without environment variables and get all Trace2 settings
     ++# from the global config.
      +
     -+test_expect_success 'setup mocked /etc/gitconfig' '
     -+	git config --file $MOCK trace2.eventTarget "$(pwd)/trace.event"
     -+'
     -+
     -+test_expect_success JSON_PP 'using mock, event stream, error event' '
     ++test_expect_success JSON_PP 'using global config, event stream, error event' '
      +	test_when_finished "rm trace.event actual expect" &&
     -+	GIT_TEST_TR2_SYSTEM_CONFIG="$MOCK" test-tool trace2 003error "hello world" "this is a test" &&
     ++	test_config_global trace2.eventTarget "$(pwd)/trace.event" &&
     ++	test-tool trace2 003error "hello world" "this is a test" &&
      +	perl "$TEST_DIRECTORY/t0212/parse_events.perl" <trace.event >actual &&
      +	sed -e "s/^|//" >expect <<-EOF &&
      +	|VAR1 = {
     @@ -503,8 +444,9 @@
      +
      +/*
      + * This table must match "enum tr2_sysenv_variable" in tr2_sysenv.h.
     -+ * These strings are constant and must match the published names as
     -+ * described in the documentation.
     ++ *
     ++ * The strings in this table are constant and must match the published
     ++ * config and environment variable names as described in the documentation.
      + *
      + * We do not define entries for the GIT_TR2_PARENT_* environment
      + * variables because they are transient and used to pass information
     @@ -512,19 +454,28 @@
      + */
      +/* clang-format off */
      +static struct tr2_sysenv_entry tr2_sysenv_settings[] = {
     -+	{ "GIT_TR2_CONFIG_PARAMS",   "trace2.configparams"     },
     -+
     -+	{ "GIT_TR2_DST_DEBUG",       "trace2.destinationdebug" },
     -+
     -+	{ "GIT_TR2",                 "trace2.normaltarget"     },
     -+	{ "GIT_TR2_BRIEF",           "trace2.normalbrief"      },
     -+
     -+	{ "GIT_TR2_EVENT",           "trace2.eventtarget"      },
     -+	{ "GIT_TR2_EVENT_BRIEF",     "trace2.eventbrief"       },
     -+	{ "GIT_TR2_EVENT_NESTING",   "trace2.eventnesting"     },
     -+
     -+	{ "GIT_TR2_PERF",            "trace2.perftarget"       },
     -+	{ "GIT_TR2_PERF_BRIEF",      "trace2.perfbrief"        },
     ++	[TR2_SYSENV_CFG_PARAM]     = { "GIT_TR2_CONFIG_PARAMS",
     ++				       "trace2.configparams" },
     ++
     ++	[TR2_SYSENV_DST_DEBUG]     = { "GIT_TR2_DST_DEBUG",
     ++				       "trace2.destinationdebug" },
     ++
     ++	[TR2_SYSENV_NORMAL]        = { "GIT_TR2",
     ++				       "trace2.normaltarget" },
     ++	[TR2_SYSENV_NORMAL_BRIEF]  = { "GIT_TR2_BRIEF",
     ++				       "trace2.normalbrief" },
     ++
     ++	[TR2_SYSENV_EVENT]         = { "GIT_TR2_EVENT",
     ++				       "trace2.eventtarget" },
     ++	[TR2_SYSENV_EVENT_BRIEF]   = { "GIT_TR2_EVENT_BRIEF",
     ++				       "trace2.eventbrief" },
     ++	[TR2_SYSENV_EVENT_NESTING] = { "GIT_TR2_EVENT_NESTING",
     ++				       "trace2.eventnesting" },
     ++
     ++	[TR2_SYSENV_PERF]          = { "GIT_TR2_PERF",
     ++				       "trace2.perftarget" },
     ++	[TR2_SYSENV_PERF_BRIEF]    = { "GIT_TR2_PERF_BRIEF",
     ++				       "trace2.perfbrief" },
      +};
      +/* clang-format on */
      +
     @@ -550,31 +501,20 @@
      + * Load Trace2 settings from the system config (usually "/etc/gitconfig"
      + * unless we were built with a runtime-prefix).  These are intended to
      + * define the default values for Trace2 as requested by the administrator.
     ++ *
     ++ * Then override with the Trace2 settings from the global config.
      + */
      +void tr2_sysenv_load(void)
      +{
     -+	const char *system_config_pathname;
     -+	const char *test_pathname;
     -+
     -+	system_config_pathname = git_etc_gitconfig();
     -+
     -+	test_pathname = getenv("GIT_TEST_TR2_SYSTEM_CONFIG");
     -+	if (test_pathname) {
     -+		if (!*test_pathname || !strcmp(test_pathname, "0"))
     -+			return; /* disable use of system config */
     -+
     -+		/* mock it with given test file */
     -+		system_config_pathname = test_pathname;
     -+	}
     ++	if (ARRAY_SIZE(tr2_sysenv_settings) != TR2_SYSENV_MUST_BE_LAST)
     ++		BUG("tr2_sysenv_settings size is wrong");
      +
     -+	if (file_exists(system_config_pathname))
     -+		git_config_from_file(tr2_sysenv_cb, system_config_pathname,
     -+				     NULL);
     ++	read_very_early_config(tr2_sysenv_cb, NULL);
      +}
      +
      +/*
     -+ * Return the value for the requested setting.  Start with the /etc/gitconfig
     -+ * value and allow the corresponding environment variable to override it.
     ++ * Return the value for the requested Trace2 setting from these sources:
     ++ * the system config, the global config, and the environment.
      + */
      +const char *tr2_sysenv_get(enum tr2_sysenv_variable var)
      +{
  5:  86d8fe28cf =  7:  2a7a933875 trace2: report peak memory usage of the process
  6:  ae11cc4186 =  8:  56f357dc7b trace2: clarify UTC datetime formatting
  7:  4352952677 !  9:  156ffde489 trace2: make SIDs more unique
     @@ -22,11 +22,11 @@
      -{"event":"cmd_name","sid":"1547659722619736-11614","thread":"main","time":"2019-01-16T17:28:42.621122Z","file":"git.c","line":432,"name":"version","hierarchy":"version"}
      -{"event":"exit","sid":"1547659722619736-11614","thread":"main","time":"2019-01-16T17:28:42.621236Z","file":"git.c","line":662,"t_abs":0.001227,"code":0}
      -{"event":"atexit","sid":"1547659722619736-11614","thread":"main","time":"2019-01-16T17:28:42.621268Z","file":"trace2/tr2_tgt_event.c","line":163,"t_abs":0.001265,"code":0}
     -+{"event":"version","sid":"20190329-144314-319944-9b68c35f-012232","thread":"main","time":"2019-01-16T17:28:42.620713Z","file":"common-main.c","line":38,"evt":"1","exe":"2.20.1.155.g426c96fcdb"}
     -+{"event":"start","sid":"20190329-144314-319944-9b68c35f-012232","thread":"main","time":"2019-01-16T17:28:42.621027Z","file":"common-main.c","line":39,"t_abs":0.001173,"argv":["git","version"]}
     -+{"event":"cmd_name","sid":"20190329-144314-319944-9b68c35f-012232","thread":"main","time":"2019-01-16T17:28:42.621122Z","file":"git.c","line":432,"name":"version","hierarchy":"version"}
     -+{"event":"exit","sid":"20190329-144314-319944-9b68c35f-012232","thread":"main","time":"2019-01-16T17:28:42.621236Z","file":"git.c","line":662,"t_abs":0.001227,"code":0}
     -+{"event":"atexit","sid":"20190329-144314-319944-9b68c35f-012232","thread":"main","time":"2019-01-16T17:28:42.621268Z","file":"trace2/tr2_tgt_event.c","line":163,"t_abs":0.001265,"code":0}
     ++{"event":"version","sid":"sid":"20190408T191610.507018Z-H9b68c35f-P028492","thread":"main","time":"2019-01-16T17:28:42.620713Z","file":"common-main.c","line":38,"evt":"1","exe":"2.20.1.155.g426c96fcdb"}
     ++{"event":"start","sid":"20190408T191610.507018Z-H9b68c35f-P028492","thread":"main","time":"2019-01-16T17:28:42.621027Z","file":"common-main.c","line":39,"t_abs":0.001173,"argv":["git","version"]}
     ++{"event":"cmd_name","sid":"20190408T191610.507018Z-H9b68c35f-P028492","thread":"main","time":"2019-01-16T17:28:42.621122Z","file":"git.c","line":432,"name":"version","hierarchy":"version"}
     ++{"event":"exit","sid":"20190408T191610.507018Z-H9b68c35f-P028492","thread":"main","time":"2019-01-16T17:28:42.621236Z","file":"git.c","line":662,"t_abs":0.001227,"code":0}
     ++{"event":"atexit","sid":"20190408T191610.507018Z-H9b68c35f-P028492","thread":"main","time":"2019-01-16T17:28:42.621268Z","file":"trace2/tr2_tgt_event.c","line":163,"t_abs":0.001265,"code":0}
       ------------
       
       == Enabling a Target
     @@ -35,10 +35,16 @@
       {
       	"event":"version",
      -	"sid":"1547659722619736-11614",
     -+	"sid":"20190329-144314-319944-9b68c35f-012232",
     ++	"sid":"20190408T191827.272759Z-H9b68c35f-P011764",
       	"thread":"main",
     - 	"time":"2019-01-16T17:28:42.620713Z",
     +-	"time":"2019-01-16T17:28:42.620713Z",
     ++	"time":"2019-04-08T19:18:27.282761Z",
       	"file":"common-main.c",
     +-	"line":38,
     ++	"line":42,
     + 	...
     + }
     + ------------
      
       diff --git a/trace2/tr2_sid.c b/trace2/tr2_sid.c
       --- a/trace2/tr2_sid.c
     @@ -56,34 +62,50 @@
      +/*
      + * Compute the final component of the SID representing the current process.
      + * This should uniquely identify the process and be a valid filename (to
     -+ * allow writing trace2 data to per-process files).
     ++ * allow writing trace2 data to per-process files).  It should also be fixed
     ++ * possible length for use as a database key.
     ++ *
     ++ * "<yyyymmdd>T<hhmmss>.<fraction>Z-<host>-<process>"
     ++ *
     ++ * where <host> is a 9 character string:
     ++ *    "H<first_8_chars_of_sha1_of_hostname>"
     ++ *    "Localhost" when no hostname.
      + *
     -+ * <yyyymmdd> '-' <hhmmss> '-' <fraction> '-' <sha1-prefix> '-' <pid>
     ++ * where <process> is a possibly wrapped PID:
     ++ *    "P<6-digit-pid>"
     ++ *    "W<wrapped-6-digit-pid>" when PID too big.
     ++ *    
      + */
      +static void tr2_sid_append_my_sid_component(void)
      +{
      +	const struct git_hash_algo *algo = &hash_algos[GIT_HASH_SHA1];
      +	struct tr2_tbuf tb_now;
      +	git_hash_ctx ctx;
     ++	uintmax_t pid = getpid();
      +	unsigned char hash[GIT_MAX_RAWSZ + 1];
      +	char hex[GIT_MAX_HEXSZ + 1];
      +	char hostname[HOST_NAME_MAX + 1];
      +
     -+	tr2_tbuf_utc_datetime_for_filename(&tb_now);
     ++	tr2_tbuf_utc_datetime(&tb_now);
      +	strbuf_addstr(&tr2sid_buf, tb_now.buf);
     -+	strbuf_addch(&tr2sid_buf, '-');
      +
     ++	strbuf_addch(&tr2sid_buf, '-');
      +	if (xgethostname(hostname, sizeof(hostname)))
     -+		xsnprintf(hostname, sizeof(hostname), "localhost");
     -+
     -+	algo->init_fn(&ctx);
     -+	algo->update_fn(&ctx, hostname, strlen(hostname));
     -+	algo->final_fn(hash, &ctx);
     -+	hash_to_hex_algop_r(hex, hash, algo);
     -+	strbuf_add(&tr2sid_buf, hex, 8);
     ++		strbuf_add(&tr2sid_buf, "Localhost", 9);
     ++	else {
     ++		algo->init_fn(&ctx);
     ++		algo->update_fn(&ctx, hostname, strlen(hostname));
     ++		algo->final_fn(hash, &ctx);
     ++		hash_to_hex_algop_r(hex, hash, algo);
     ++		strbuf_addch(&tr2sid_buf, 'H');
     ++		strbuf_add(&tr2sid_buf, hex, 8);
     ++	}
      +
      +	strbuf_addch(&tr2sid_buf, '-');
     -+	strbuf_addf(&tr2sid_buf, "%06"PRIuMAX, (uintmax_t)getpid());
     ++	if (pid > 999999)
     ++		strbuf_addf(&tr2sid_buf, "W%06d", (int)(pid % 1000000));
     ++	else
     ++		strbuf_addf(&tr2sid_buf, "P%06d", (int)pid);
      +}
      +
       /*
     @@ -117,7 +139,7 @@
       		  (long)tv.tv_usec);
       }
      +
     -+void tr2_tbuf_utc_datetime_for_filename(struct tr2_tbuf *tb)
     ++void tr2_tbuf_utc_datetime(struct tr2_tbuf *tb)
      +{
      +	struct timeval tv;
      +	struct tm tm;
     @@ -128,7 +150,7 @@
      +	gmtime_r(&secs, &tm);
      +
      +	xsnprintf(tb->buf, sizeof(tb->buf),
     -+		  "%4d%02d%02d-%02d%02d%02d-%06ld", tm.tm_year + 1900,
     ++		  "%4d%02d%02dT%02d%02d%02d.%06ldZ", tm.tm_year + 1900,
      +		  tm.tm_mon + 1, tm.tm_mday, tm.tm_hour, tm.tm_min, tm.tm_sec,
      +		  (long)tv.tv_usec);
      +}
     @@ -140,6 +162,6 @@
        * Fill buffer with formatted UTC datatime string.
        */
       void tr2_tbuf_utc_datetime_extended(struct tr2_tbuf *tb);
     -+void tr2_tbuf_utc_datetime_for_filename(struct tr2_tbuf *tb);
     ++void tr2_tbuf_utc_datetime(struct tr2_tbuf *tb);
       
       #endif /* TR2_TBUF_H */
  -:  ---------- > 10:  285beb2b2d trace2: update docs to describe system/global config settings

-- 
gitgitgadget

^ permalink raw reply	[flat|nested] 68+ messages in thread

* [PATCH v3 01/10] config: initialize opts structure in repo_read_config()
  2019-04-11 15:18   ` [PATCH v3 00/10] " Jeff Hostetler via GitGitGadget
@ 2019-04-11 15:18     ` Jeff Hostetler via GitGitGadget
  2019-04-12  3:52       ` Jonathan Nieder
  2019-04-11 15:18     ` [PATCH v3 03/10] trace2: add absolute elapsed time to start event Jeff Hostetler via GitGitGadget
                       ` (10 subsequent siblings)
  11 siblings, 1 reply; 68+ messages in thread
From: Jeff Hostetler via GitGitGadget @ 2019-04-11 15:18 UTC (permalink / raw)
  To: git
  Cc: gitster, peff, jrnieder, steadmon, avarab, Junio C Hamano,
	Jeff Hostetler

From: Jeff Hostetler <jeffhost@microsoft.com>

Initialize opts structure in repo_read_config().

This change fixes a crash in later commit after a new field is added
to the structure.

In commit 3b256228a66f8587661481ef3e08259864f3ba2a, repo_read_config()
was added.  It only initializes 3 fields in the opts structure.  It is
passed to config_with_options() and then to do_git_config_sequence().
However, do_git_config_sequence() drops the opts on the floor and calls
git_config_from_file() rather than git_config_from_file_with_options(),
so that may be why this hasn't been a problem in the past.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Jeff Hostetler <jeffhost@microsoft.com>
---
 config.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/config.c b/config.c
index 0f0cdd8c0f..8e5f45fa20 100644
--- a/config.c
+++ b/config.c
@@ -2011,7 +2011,7 @@ int git_configset_get_pathname(struct config_set *cs, const char *key, const cha
 /* Functions use to read configuration from a repository */
 static void repo_read_config(struct repository *repo)
 {
-	struct config_options opts;
+	struct config_options opts = {0};
 
 	opts.respect_includes = 1;
 	opts.commondir = repo->commondir;
-- 
gitgitgadget


^ permalink raw reply	[flat|nested] 68+ messages in thread

* [PATCH v3 03/10] trace2: add absolute elapsed time to start event
  2019-04-11 15:18   ` [PATCH v3 00/10] " Jeff Hostetler via GitGitGadget
  2019-04-11 15:18     ` [PATCH v3 01/10] config: initialize opts structure in repo_read_config() Jeff Hostetler via GitGitGadget
@ 2019-04-11 15:18     ` Jeff Hostetler via GitGitGadget
  2019-04-11 15:18     ` [PATCH v3 02/10] trace2: refactor setting process starting time Jeff Hostetler via GitGitGadget
                       ` (9 subsequent siblings)
  11 siblings, 0 replies; 68+ messages in thread
From: Jeff Hostetler via GitGitGadget @ 2019-04-11 15:18 UTC (permalink / raw)
  To: git
  Cc: gitster, peff, jrnieder, steadmon, avarab, Junio C Hamano,
	Jeff Hostetler

From: Jeff Hostetler <jeffhost@microsoft.com>

Add elapsed process time to "start" event to measure
the performance of early process startup.

Signed-off-by: Jeff Hostetler <jeffhost@microsoft.com>
---
 Documentation/technical/api-trace2.txt | 11 ++++++-----
 t/t0211-trace2-perf.sh                 | 12 ++++++------
 trace2.c                               |  8 +++++++-
 trace2/tr2_tgt.h                       |  1 +
 trace2/tr2_tgt_event.c                 |  5 ++++-
 trace2/tr2_tgt_normal.c                |  3 ++-
 trace2/tr2_tgt_perf.c                  |  7 ++++---
 7 files changed, 30 insertions(+), 17 deletions(-)

diff --git a/Documentation/technical/api-trace2.txt b/Documentation/technical/api-trace2.txt
index f37fccf1da..baaa1153bb 100644
--- a/Documentation/technical/api-trace2.txt
+++ b/Documentation/technical/api-trace2.txt
@@ -60,7 +60,7 @@ git version 2.20.1.155.g426c96fcdb
 ------------
 $ cat ~/log.perf
 12:28:42.620675 common-main.c:38                  | d0 | main                     | version      |     |           |           |            | 2.20.1.155.g426c96fcdb
-12:28:42.621001 common-main.c:39                  | d0 | main                     | start        |     |           |           |            | git version
+12:28:42.621001 common-main.c:39                  | d0 | main                     | start        |     |  0.001173 |           |            | git version
 12:28:42.621111 git.c:432                         | d0 | main                     | cmd_name     |     |           |           |            | version (version)
 12:28:42.621225 git.c:662                         | d0 | main                     | exit         |     |  0.001227 |           |            | code:0
 12:28:42.621259 trace2/tr2_tgt_perf.c:211         | d0 | main                     | atexit       |     |  0.001265 |           |            | code:0
@@ -79,7 +79,7 @@ git version 2.20.1.155.g426c96fcdb
 ------------
 $ cat ~/log.event
 {"event":"version","sid":"1547659722619736-11614","thread":"main","time":"2019-01-16 17:28:42.620713","file":"common-main.c","line":38,"evt":"1","exe":"2.20.1.155.g426c96fcdb"}
-{"event":"start","sid":"1547659722619736-11614","thread":"main","time":"2019-01-16 17:28:42.621027","file":"common-main.c","line":39,"argv":["git","version"]}
+{"event":"start","sid":"1547659722619736-11614","thread":"main","time":"2019-01-16 17:28:42.621027","file":"common-main.c","line":39,"t_abs":0.001173,"argv":["git","version"]}
 {"event":"cmd_name","sid":"1547659722619736-11614","thread":"main","time":"2019-01-16 17:28:42.621122","file":"git.c","line":432,"name":"version","hierarchy":"version"}
 {"event":"exit","sid":"1547659722619736-11614","thread":"main","time":"2019-01-16 17:28:42.621236","file":"git.c","line":662,"t_abs":0.001227,"code":0}
 {"event":"atexit","sid":"1547659722619736-11614","thread":"main","time":"2019-01-16 17:28:42.621268","file":"trace2/tr2_tgt_event.c","line":163,"t_abs":0.001265,"code":0}
@@ -601,6 +601,7 @@ from all events and the `time` field is only present on the "start" and
 {
 	"event":"start",
 	...
+	"t_abs":0.001227, # elapsed time in seconds
 	"argv":["git","version"]
 }
 ------------
@@ -1118,7 +1119,7 @@ $ git status
 
 $ cat ~/log.perf
 d0 | main                     | version      |     |           |           |            | 2.20.1.160.g5676107ecd.dirty
-d0 | main                     | start        |     |           |           |            | git status
+d0 | main                     | start        |     |  0.001173 |           |            | git status
 d0 | main                     | def_repo     | r1  |           |           |            | worktree:/Users/jeffhost/work/gfw
 d0 | main                     | cmd_name     |     |           |           |            | status (status)
 ...
@@ -1163,7 +1164,7 @@ $ git status
 ...
 $ cat ~/log.perf
 d0 | main                     | version      |     |           |           |            | 2.20.1.162.gb4ccea44db.dirty
-d0 | main                     | start        |     |           |           |            | git status
+d0 | main                     | start        |     |  0.001173 |           |            | git status
 d0 | main                     | def_repo     | r1  |           |           |            | worktree:/Users/jeffhost/work/gfw
 d0 | main                     | cmd_name     |     |           |           |            | status (status)
 ...
@@ -1219,7 +1220,7 @@ $ git status
 ...
 $ cat ~/log.perf
 d0 | main                     | version      |     |           |           |            | 2.20.1.156.gf9916ae094.dirty
-d0 | main                     | start        |     |           |           |            | git status
+d0 | main                     | start        |     |  0.001173 |           |            | git status
 d0 | main                     | def_repo     | r1  |           |           |            | worktree:/Users/jeffhost/work/gfw
 d0 | main                     | cmd_name     |     |           |           |            | status (status)
 d0 | main                     | region_enter | r1  |  0.001791 |           | index      | label:do_read_index .git/index
diff --git a/t/t0211-trace2-perf.sh b/t/t0211-trace2-perf.sh
index 953e2f7847..c9694b29f7 100755
--- a/t/t0211-trace2-perf.sh
+++ b/t/t0211-trace2-perf.sh
@@ -50,7 +50,7 @@ test_expect_success 'perf stream, return code 0' '
 	perl "$TEST_DIRECTORY/t0211/scrub_perf.perl" <trace.perf >actual &&
 	cat >expect <<-EOF &&
 		d0|main|version|||||$V
-		d0|main|start|||||_EXE_ trace2 001return 0
+		d0|main|start||_T_ABS_|||_EXE_ trace2 001return 0
 		d0|main|cmd_name|||||trace2 (trace2)
 		d0|main|exit||_T_ABS_|||code:0
 		d0|main|atexit||_T_ABS_|||code:0
@@ -64,7 +64,7 @@ test_expect_success 'perf stream, return code 1' '
 	perl "$TEST_DIRECTORY/t0211/scrub_perf.perl" <trace.perf >actual &&
 	cat >expect <<-EOF &&
 		d0|main|version|||||$V
-		d0|main|start|||||_EXE_ trace2 001return 1
+		d0|main|start||_T_ABS_|||_EXE_ trace2 001return 1
 		d0|main|cmd_name|||||trace2 (trace2)
 		d0|main|exit||_T_ABS_|||code:1
 		d0|main|atexit||_T_ABS_|||code:1
@@ -82,7 +82,7 @@ test_expect_success 'perf stream, error event' '
 	perl "$TEST_DIRECTORY/t0211/scrub_perf.perl" <trace.perf >actual &&
 	cat >expect <<-EOF &&
 		d0|main|version|||||$V
-		d0|main|start|||||_EXE_ trace2 003error '\''hello world'\'' '\''this is a test'\''
+		d0|main|start||_T_ABS_|||_EXE_ trace2 003error '\''hello world'\'' '\''this is a test'\''
 		d0|main|cmd_name|||||trace2 (trace2)
 		d0|main|error|||||hello world
 		d0|main|error|||||this is a test
@@ -128,15 +128,15 @@ test_expect_success 'perf stream, child processes' '
 	perl "$TEST_DIRECTORY/t0211/scrub_perf.perl" <trace.perf >actual &&
 	cat >expect <<-EOF &&
 		d0|main|version|||||$V
-		d0|main|start|||||_EXE_ trace2 004child test-tool trace2 004child test-tool trace2 001return 0
+		d0|main|start||_T_ABS_|||_EXE_ trace2 004child test-tool trace2 004child test-tool trace2 001return 0
 		d0|main|cmd_name|||||trace2 (trace2)
 		d0|main|child_start||_T_ABS_|||[ch0] class:? argv: test-tool trace2 004child test-tool trace2 001return 0
 		d1|main|version|||||$V
-		d1|main|start|||||_EXE_ trace2 004child test-tool trace2 001return 0
+		d1|main|start||_T_ABS_|||_EXE_ trace2 004child test-tool trace2 001return 0
 		d1|main|cmd_name|||||trace2 (trace2/trace2)
 		d1|main|child_start||_T_ABS_|||[ch0] class:? argv: test-tool trace2 001return 0
 		d2|main|version|||||$V
-		d2|main|start|||||_EXE_ trace2 001return 0
+		d2|main|start||_T_ABS_|||_EXE_ trace2 001return 0
 		d2|main|cmd_name|||||trace2 (trace2/trace2/trace2)
 		d2|main|exit||_T_ABS_|||code:0
 		d2|main|atexit||_T_ABS_|||code:0
diff --git a/trace2.c b/trace2.c
index 6dd51e6aa5..1c180062dd 100644
--- a/trace2.c
+++ b/trace2.c
@@ -182,13 +182,19 @@ void trace2_cmd_start_fl(const char *file, int line, const char **argv)
 {
 	struct tr2_tgt *tgt_j;
 	int j;
+	uint64_t us_now;
+	uint64_t us_elapsed_absolute;
 
 	if (!trace2_enabled)
 		return;
 
+	us_now = getnanotime() / 1000;
+	us_elapsed_absolute = tr2tls_absolute_elapsed(us_now);
+
 	for_each_wanted_builtin (j, tgt_j)
 		if (tgt_j->pfn_start_fl)
-			tgt_j->pfn_start_fl(file, line, argv);
+			tgt_j->pfn_start_fl(file, line, us_elapsed_absolute,
+					    argv);
 }
 
 int trace2_cmd_exit_fl(const char *file, int line, int code)
diff --git a/trace2/tr2_tgt.h b/trace2/tr2_tgt.h
index 297bb8ffbe..7b90469212 100644
--- a/trace2/tr2_tgt.h
+++ b/trace2/tr2_tgt.h
@@ -15,6 +15,7 @@ typedef void(tr2_tgt_term_t)(void);
 typedef void(tr2_tgt_evt_version_fl_t)(const char *file, int line);
 
 typedef void(tr2_tgt_evt_start_fl_t)(const char *file, int line,
+				     uint64_t us_elapsed_absolute,
 				     const char **argv);
 typedef void(tr2_tgt_evt_exit_fl_t)(const char *file, int line,
 				    uint64_t us_elapsed_absolute, int code);
diff --git a/trace2/tr2_tgt_event.c b/trace2/tr2_tgt_event.c
index 107cb5317d..89a4d3ae9a 100644
--- a/trace2/tr2_tgt_event.c
+++ b/trace2/tr2_tgt_event.c
@@ -122,13 +122,16 @@ static void fn_version_fl(const char *file, int line)
 	jw_release(&jw);
 }
 
-static void fn_start_fl(const char *file, int line, const char **argv)
+static void fn_start_fl(const char *file, int line,
+			uint64_t us_elapsed_absolute, const char **argv)
 {
 	const char *event_name = "start";
 	struct json_writer jw = JSON_WRITER_INIT;
+	double t_abs = (double)us_elapsed_absolute / 1000000.0;
 
 	jw_object_begin(&jw, 0);
 	event_fmt_prepare(event_name, file, line, NULL, &jw);
+	jw_object_double(&jw, "t_abs", 6, t_abs);
 	jw_object_inline_begin_array(&jw, "argv");
 	jw_array_argv(&jw, argv);
 	jw_end(&jw);
diff --git a/trace2/tr2_tgt_normal.c b/trace2/tr2_tgt_normal.c
index 547183d5b6..57f3e18f5b 100644
--- a/trace2/tr2_tgt_normal.c
+++ b/trace2/tr2_tgt_normal.c
@@ -81,7 +81,8 @@ static void fn_version_fl(const char *file, int line)
 	strbuf_release(&buf_payload);
 }
 
-static void fn_start_fl(const char *file, int line, const char **argv)
+static void fn_start_fl(const char *file, int line,
+			uint64_t us_elapsed_absolute, const char **argv)
 {
 	struct strbuf buf_payload = STRBUF_INIT;
 
diff --git a/trace2/tr2_tgt_perf.c b/trace2/tr2_tgt_perf.c
index f0746fcf86..9c3b4d8a0f 100644
--- a/trace2/tr2_tgt_perf.c
+++ b/trace2/tr2_tgt_perf.c
@@ -159,15 +159,16 @@ static void fn_version_fl(const char *file, int line)
 	strbuf_release(&buf_payload);
 }
 
-static void fn_start_fl(const char *file, int line, const char **argv)
+static void fn_start_fl(const char *file, int line,
+			uint64_t us_elapsed_absolute, const char **argv)
 {
 	const char *event_name = "start";
 	struct strbuf buf_payload = STRBUF_INIT;
 
 	sq_quote_argv_pretty(&buf_payload, argv);
 
-	perf_io_write_fl(file, line, event_name, NULL, NULL, NULL, NULL,
-			 &buf_payload);
+	perf_io_write_fl(file, line, event_name, NULL, &us_elapsed_absolute,
+			 NULL, NULL, &buf_payload);
 	strbuf_release(&buf_payload);
 }
 
-- 
gitgitgadget


^ permalink raw reply	[flat|nested] 68+ messages in thread

* [PATCH v3 02/10] trace2: refactor setting process starting time
  2019-04-11 15:18   ` [PATCH v3 00/10] " Jeff Hostetler via GitGitGadget
  2019-04-11 15:18     ` [PATCH v3 01/10] config: initialize opts structure in repo_read_config() Jeff Hostetler via GitGitGadget
  2019-04-11 15:18     ` [PATCH v3 03/10] trace2: add absolute elapsed time to start event Jeff Hostetler via GitGitGadget
@ 2019-04-11 15:18     ` Jeff Hostetler via GitGitGadget
  2019-04-11 15:18     ` [PATCH v3 04/10] trace2: find exec-dir before trace2 initialization Jeff Hostetler via GitGitGadget
                       ` (8 subsequent siblings)
  11 siblings, 0 replies; 68+ messages in thread
From: Jeff Hostetler via GitGitGadget @ 2019-04-11 15:18 UTC (permalink / raw)
  To: git
  Cc: gitster, peff, jrnieder, steadmon, avarab, Junio C Hamano,
	Jeff Hostetler

From: Jeff Hostetler <jeffhost@microsoft.com>

Create trace2_initialize_clock() and call from main() to capture
process start time in isolation and before other sub-systems are
ready.

Signed-off-by: Jeff Hostetler <jeffhost@microsoft.com>
---
 Documentation/technical/api-trace2.txt | 12 ++++++--
 common-main.c                          |  2 ++
 compat/mingw.c                         |  2 ++
 trace2.c                               |  7 ++++-
 trace2.h                               | 17 ++++++++++++
 trace2/tr2_tls.c                       | 38 ++++++++++++++++----------
 trace2/tr2_tls.h                       |  8 +++++-
 7 files changed, 67 insertions(+), 19 deletions(-)

diff --git a/Documentation/technical/api-trace2.txt b/Documentation/technical/api-trace2.txt
index 2de565fa3d..f37fccf1da 100644
--- a/Documentation/technical/api-trace2.txt
+++ b/Documentation/technical/api-trace2.txt
@@ -160,17 +160,23 @@ purposes.
 
 These are concerned with the lifetime of the overall git process.
 
+`void trace2_initialize_clock()`::
+
+	Initialize the Trace2 start clock and nothing else.  This should
+	be called at the very top of main() to capture the process start
+	time and reduce startup order dependencies.
+
 `void trace2_initialize()`::
 
 	Determines if any Trace2 Targets should be enabled and
-	initializes the Trace2 facility.  This includes starting the
-	elapsed time clocks and thread local storage (TLS).
+	initializes the Trace2 facility.  This includes setting up the
+	Trace2 thread local storage (TLS).
 +
 This function emits a "version" message containing the version of git
 and the Trace2 protocol.
 +
 This function should be called from `main()` as early as possible in
-the life of the process.
+the life of the process after essential process initialization.
 
 `int trace2_is_enabled()`::
 
diff --git a/common-main.c b/common-main.c
index d484aec209..6137af0e63 100644
--- a/common-main.c
+++ b/common-main.c
@@ -27,6 +27,8 @@ int main(int argc, const char **argv)
 {
 	int result;
 
+	trace2_initialize_clock();
+
 	/*
 	 * Always open file descriptors 0/1/2 to avoid clobbering files
 	 * in die().  It also avoids messing up when the pipes are dup'ed
diff --git a/compat/mingw.c b/compat/mingw.c
index 6b04514cdc..a2f74aca6a 100644
--- a/compat/mingw.c
+++ b/compat/mingw.c
@@ -2569,6 +2569,8 @@ void mingw_startup(void)
 	wchar_t **wenv, **wargv;
 	_startupinfo si;
 
+	trace2_initialize_clock();
+
 	maybe_redirect_std_handles();
 
 	/* get wide char arguments and environment */
diff --git a/trace2.c b/trace2.c
index ccccd4ef09..6dd51e6aa5 100644
--- a/trace2.c
+++ b/trace2.c
@@ -142,6 +142,11 @@ static void tr2main_signal_handler(int signo)
 	raise(signo);
 }
 
+void trace2_initialize_clock(void)
+{
+	tr2tls_start_process_clock();
+}
+
 void trace2_initialize_fl(const char *file, int line)
 {
 	struct tr2_tgt *tgt_j;
@@ -428,7 +433,7 @@ void trace2_thread_start_fl(const char *file, int line, const char *thread_name)
 	us_now = getnanotime() / 1000;
 	us_elapsed_absolute = tr2tls_absolute_elapsed(us_now);
 
-	tr2tls_create_self(thread_name);
+	tr2tls_create_self(thread_name, us_now);
 
 	for_each_wanted_builtin (j, tgt_j)
 		if (tgt_j->pfn_thread_start_fl)
diff --git a/trace2.h b/trace2.h
index ae5020d0e6..8f89e70c44 100644
--- a/trace2.h
+++ b/trace2.h
@@ -19,6 +19,23 @@ struct json_writer;
  * [] trace2_printf*    -- legacy trace[1] messages.
  */
 
+/*
+ * Initialize the TRACE2 clock and do nothing else, in particular
+ * no mallocs, no system inspection, and no environment inspection.
+ *
+ * This should be called at the very top of main() to capture the
+ * process start time.  This is intended to reduce chicken-n-egg
+ * bootstrap pressure.
+ *
+ * It is safe to call this more than once.  This allows capturing
+ * absolute startup costs on Windows which uses a little trickery
+ * to do setup work before common-main.c:main() is called.
+ *
+ * The main trace2_initialize_fl() may be called a little later
+ * after more infrastructure is established.
+ */
+void trace2_initialize_clock(void);
+
 /*
  * Initialize TRACE2 tracing facility if any of the builtin TRACE2
  * targets are enabled in the environment.  Emits a 'version' event.
diff --git a/trace2/tr2_tls.c b/trace2/tr2_tls.c
index 8e65b0361d..31fb529f93 100644
--- a/trace2/tr2_tls.c
+++ b/trace2/tr2_tls.c
@@ -10,16 +10,30 @@
 #define TR2_REGION_NESTING_INITIAL_SIZE (100)
 
 static struct tr2tls_thread_ctx *tr2tls_thread_main;
-static uint64_t tr2tls_us_start_main;
+static uint64_t tr2tls_us_start_process;
 
 static pthread_mutex_t tr2tls_mutex;
 static pthread_key_t tr2tls_key;
 
 static int tr2_next_thread_id; /* modify under lock */
 
-struct tr2tls_thread_ctx *tr2tls_create_self(const char *thread_name)
+void tr2tls_start_process_clock(void)
+{
+	if (tr2tls_us_start_process)
+		return;
+
+	/*
+	 * Keep the absolute start time of the process (i.e. the main
+	 * process) in a fixed variable since other threads need to
+	 * access it.  This allows them to do that without a lock on
+	 * main thread's array data (because of reallocs).
+	 */
+	tr2tls_us_start_process = getnanotime() / 1000;
+}
+
+struct tr2tls_thread_ctx *tr2tls_create_self(const char *thread_name,
+					     uint64_t us_thread_start)
 {
-	uint64_t us_now = getnanotime() / 1000;
 	struct tr2tls_thread_ctx *ctx = xcalloc(1, sizeof(*ctx));
 
 	/*
@@ -29,7 +43,7 @@ struct tr2tls_thread_ctx *tr2tls_create_self(const char *thread_name)
 	 */
 	ctx->alloc = TR2_REGION_NESTING_INITIAL_SIZE;
 	ctx->array_us_start = (uint64_t *)xcalloc(ctx->alloc, sizeof(uint64_t));
-	ctx->array_us_start[ctx->nr_open_regions++] = us_now;
+	ctx->array_us_start[ctx->nr_open_regions++] = us_thread_start;
 
 	ctx->thread_id = tr2tls_locked_increment(&tr2_next_thread_id);
 
@@ -55,7 +69,7 @@ struct tr2tls_thread_ctx *tr2tls_get_self(void)
 	 * here and silently continue.
 	 */
 	if (!ctx)
-		ctx = tr2tls_create_self("unknown");
+		ctx = tr2tls_create_self("unknown", getnanotime() / 1000);
 
 	return ctx;
 }
@@ -124,22 +138,18 @@ uint64_t tr2tls_absolute_elapsed(uint64_t us)
 	if (!tr2tls_thread_main)
 		return 0;
 
-	return us - tr2tls_us_start_main;
+	return us - tr2tls_us_start_process;
 }
 
 void tr2tls_init(void)
 {
+	tr2tls_start_process_clock();
+
 	pthread_key_create(&tr2tls_key, NULL);
 	init_recursive_mutex(&tr2tls_mutex);
 
-	tr2tls_thread_main = tr2tls_create_self("main");
-	/*
-	 * Keep a copy of the absolute start time of the main thread
-	 * in a fixed variable since other threads need to access it.
-	 * This also eliminates the need to lock accesses to the main
-	 * thread's array (because of reallocs).
-	 */
-	tr2tls_us_start_main = tr2tls_thread_main->array_us_start[0];
+	tr2tls_thread_main = tr2tls_create_self("main",
+						tr2tls_us_start_process);
 }
 
 void tr2tls_release(void)
diff --git a/trace2/tr2_tls.h b/trace2/tr2_tls.h
index bb80e3f8e7..b1e327a928 100644
--- a/trace2/tr2_tls.h
+++ b/trace2/tr2_tls.h
@@ -31,7 +31,8 @@ struct tr2tls_thread_ctx {
  * In this and all following functions the term "self" refers to the
  * current thread.
  */
-struct tr2tls_thread_ctx *tr2tls_create_self(const char *thread_name);
+struct tr2tls_thread_ctx *tr2tls_create_self(const char *thread_name,
+					     uint64_t us_thread_start);
 
 /*
  * Get our TLS data.
@@ -94,4 +95,9 @@ void tr2tls_release(void);
  */
 int tr2tls_locked_increment(int *p);
 
+/*
+ * Capture the process start time and do nothing else.
+ */
+void tr2tls_start_process_clock(void);
+
 #endif /* TR2_TLS_H */
-- 
gitgitgadget


^ permalink raw reply	[flat|nested] 68+ messages in thread

* [PATCH v3 04/10] trace2: find exec-dir before trace2 initialization
  2019-04-11 15:18   ` [PATCH v3 00/10] " Jeff Hostetler via GitGitGadget
                       ` (2 preceding siblings ...)
  2019-04-11 15:18     ` [PATCH v3 02/10] trace2: refactor setting process starting time Jeff Hostetler via GitGitGadget
@ 2019-04-11 15:18     ` Jeff Hostetler via GitGitGadget
  2019-04-11 15:18     ` [PATCH v3 05/10] config: add read_very_early_config() Jeff Hostetler via GitGitGadget
                       ` (7 subsequent siblings)
  11 siblings, 0 replies; 68+ messages in thread
From: Jeff Hostetler via GitGitGadget @ 2019-04-11 15:18 UTC (permalink / raw)
  To: git
  Cc: gitster, peff, jrnieder, steadmon, avarab, Junio C Hamano,
	Jeff Hostetler

From: Jeff Hostetler <jeffhost@microsoft.com>

Teach Git to resolve the executable directory before initializing
Trace2.  This allows the system configuration directory to be
discovered earlier (because it is sometimes relative to the prefix
or runtime-prefix).

This will be used by the next commit to allow trace2 settings to
be loaded from the system config.

Signed-off-by: Jeff Hostetler <jeffhost@microsoft.com>
---
 common-main.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/common-main.c b/common-main.c
index 6137af0e63..299ca62a72 100644
--- a/common-main.c
+++ b/common-main.c
@@ -37,12 +37,12 @@ int main(int argc, const char **argv)
 	sanitize_stdfds();
 	restore_sigpipe_to_default();
 
+	git_resolve_executable_dir(argv[0]);
+
 	trace2_initialize();
 	trace2_cmd_start(argv);
 	trace2_collect_process_info();
 
-	git_resolve_executable_dir(argv[0]);
-
 	git_setup_gettext();
 
 	initialize_the_repository();
-- 
gitgitgadget


^ permalink raw reply	[flat|nested] 68+ messages in thread

* [PATCH v3 05/10] config: add read_very_early_config()
  2019-04-11 15:18   ` [PATCH v3 00/10] " Jeff Hostetler via GitGitGadget
                       ` (3 preceding siblings ...)
  2019-04-11 15:18     ` [PATCH v3 04/10] trace2: find exec-dir before trace2 initialization Jeff Hostetler via GitGitGadget
@ 2019-04-11 15:18     ` Jeff Hostetler via GitGitGadget
  2019-04-11 15:18     ` [PATCH v3 06/10] trace2: use system/global config for default trace2 settings Jeff Hostetler via GitGitGadget
                       ` (6 subsequent siblings)
  11 siblings, 0 replies; 68+ messages in thread
From: Jeff Hostetler via GitGitGadget @ 2019-04-11 15:18 UTC (permalink / raw)
  To: git
  Cc: gitster, peff, jrnieder, steadmon, avarab, Junio C Hamano,
	Jeff Hostetler

From: Jeff Hostetler <jeffhost@microsoft.com>

Created an even lighter version of read_early_config() that
only looks at system and global config settings.  It omits
repo-local, worktree-local, and command-line settings.

Signed-off-by: Jeff Hostetler <jeffhost@microsoft.com>
---
 config.c | 25 ++++++++++++++++++++++---
 config.h |  4 ++++
 2 files changed, 26 insertions(+), 3 deletions(-)

diff --git a/config.c b/config.c
index 8e5f45fa20..5b10f18088 100644
--- a/config.c
+++ b/config.c
@@ -1688,14 +1688,16 @@ static int do_git_config_sequence(const struct config_options *opts,
 		ret += git_config_from_file(fn, user_config, data);
 
 	current_parsing_scope = CONFIG_SCOPE_REPO;
-	if (repo_config && !access_or_die(repo_config, R_OK, 0))
+	if (!opts->ignore_repo &&
+	    repo_config && !access_or_die(repo_config, R_OK, 0))
 		ret += git_config_from_file(fn, repo_config, data);
 
 	/*
 	 * Note: this should have a new scope, CONFIG_SCOPE_WORKTREE.
 	 * But let's not complicate things before it's actually needed.
 	 */
-	if (repository_format_worktree_config) {
+	if (!opts->ignore_worktree &&
+	    repository_format_worktree_config) {
 		char *path = git_pathdup("config.worktree");
 		if (!access_or_die(path, R_OK, 0))
 			ret += git_config_from_file(fn, path, data);
@@ -1703,7 +1705,8 @@ static int do_git_config_sequence(const struct config_options *opts,
 	}
 
 	current_parsing_scope = CONFIG_SCOPE_CMDLINE;
-	if (git_config_from_parameters(fn, data) < 0)
+	if (!opts->ignore_cmdline &&
+	    git_config_from_parameters(fn, data) < 0)
 		die(_("unable to parse command-line config"));
 
 	current_parsing_scope = CONFIG_SCOPE_UNKNOWN;
@@ -1794,6 +1797,22 @@ void read_early_config(config_fn_t cb, void *data)
 	strbuf_release(&gitdir);
 }
 
+/*
+ * Read config but only enumerate system and global settings.
+ * Omit any repo-local, worktree-local, or command-line settings.
+ */
+void read_very_early_config(config_fn_t cb, void *data)
+{
+	struct config_options opts = {0};
+
+	opts.respect_includes = 1;
+	opts.ignore_repo = 1;
+	opts.ignore_worktree = 1;
+	opts.ignore_cmdline = 1;
+
+	config_with_options(cb, data, NULL, &opts);
+}
+
 static struct config_set_element *configset_find_element(struct config_set *cs, const char *key)
 {
 	struct config_set_element k;
diff --git a/config.h b/config.h
index ee5d3fa7b4..6a58d61d22 100644
--- a/config.h
+++ b/config.h
@@ -55,6 +55,9 @@ typedef int (*config_parser_event_fn_t)(enum config_event_t type,
 
 struct config_options {
 	unsigned int respect_includes : 1;
+	unsigned int ignore_repo : 1;
+	unsigned int ignore_worktree : 1;
+	unsigned int ignore_cmdline : 1;
 	const char *commondir;
 	const char *git_dir;
 	config_parser_event_fn_t event_fn;
@@ -83,6 +86,7 @@ extern int git_config_from_blob_oid(config_fn_t fn, const char *name,
 extern void git_config_push_parameter(const char *text);
 extern int git_config_from_parameters(config_fn_t fn, void *data);
 extern void read_early_config(config_fn_t cb, void *data);
+extern void read_very_early_config(config_fn_t cb, void *data);
 extern void git_config(config_fn_t fn, void *);
 extern int config_with_options(config_fn_t fn, void *,
 			       struct git_config_source *config_source,
-- 
gitgitgadget


^ permalink raw reply	[flat|nested] 68+ messages in thread

* [PATCH v3 06/10] trace2: use system/global config for default trace2 settings
  2019-04-11 15:18   ` [PATCH v3 00/10] " Jeff Hostetler via GitGitGadget
                       ` (4 preceding siblings ...)
  2019-04-11 15:18     ` [PATCH v3 05/10] config: add read_very_early_config() Jeff Hostetler via GitGitGadget
@ 2019-04-11 15:18     ` Jeff Hostetler via GitGitGadget
  2019-04-11 15:18     ` [PATCH v3 07/10] trace2: report peak memory usage of the process Jeff Hostetler via GitGitGadget
                       ` (5 subsequent siblings)
  11 siblings, 0 replies; 68+ messages in thread
From: Jeff Hostetler via GitGitGadget @ 2019-04-11 15:18 UTC (permalink / raw)
  To: git
  Cc: gitster, peff, jrnieder, steadmon, avarab, Junio C Hamano,
	Jeff Hostetler

From: Jeff Hostetler <jeffhost@microsoft.com>

Teach git to read the system and global config files for
default Trace2 settings.  This allows system-wide Trace2 settings to
be installed and inherited to make it easier to manage a collection of
systems.

The original GIT_TR2* environment variables are loaded afterwards and
can be used to override the system settings.

Only the system and global config files are used.  Repo and worktree
local config files are ignored.  Likewise, the "-c" command line
arguments are also ignored.  These limits are for performance reasons.

(1) For users not using Trace2, there should be minimal overhead to
detect that Trace2 is not enabled.  In particular, Trace2 should not
allocate lots of otherwise unused data strucutres.

(2) For accurate performance measurements, Trace2 should be initialized
as early in the git process as possible, and before most of the normal
git process initialization (which involves discovering the .git directory
and reading a hierarchy of config files).

Signed-off-by: Jeff Hostetler <jeffhost@microsoft.com>
---
 Makefile                 |   1 +
 t/t0210-trace2-normal.sh |  49 +++++++++++++--
 t/t0211-trace2-perf.sh   |  31 ++++++++--
 t/t0212-trace2-event.sh  |  42 +++++++++++--
 trace2.c                 |   4 ++
 trace2.h                 |  12 ++--
 trace2/tr2_cfg.c         |   7 +--
 trace2/tr2_dst.c         |  24 ++++----
 trace2/tr2_dst.h         |   3 +-
 trace2/tr2_sysenv.c      | 127 +++++++++++++++++++++++++++++++++++++++
 trace2/tr2_sysenv.h      |  36 +++++++++++
 trace2/tr2_tgt_event.c   |  46 +++++++-------
 trace2/tr2_tgt_normal.c  |  16 ++---
 trace2/tr2_tgt_perf.c    |  16 ++---
 14 files changed, 338 insertions(+), 76 deletions(-)
 create mode 100644 trace2/tr2_sysenv.c
 create mode 100644 trace2/tr2_sysenv.h

diff --git a/Makefile b/Makefile
index 3e03290d8f..9ddfa3dfe7 100644
--- a/Makefile
+++ b/Makefile
@@ -1005,6 +1005,7 @@ LIB_OBJS += trace2/tr2_cfg.o
 LIB_OBJS += trace2/tr2_cmd_name.o
 LIB_OBJS += trace2/tr2_dst.o
 LIB_OBJS += trace2/tr2_sid.o
+LIB_OBJS += trace2/tr2_sysenv.o
 LIB_OBJS += trace2/tr2_tbuf.o
 LIB_OBJS += trace2/tr2_tgt_event.o
 LIB_OBJS += trace2/tr2_tgt_normal.o
diff --git a/t/t0210-trace2-normal.sh b/t/t0210-trace2-normal.sh
index 03a0aedb1d..4e2d4c7997 100755
--- a/t/t0210-trace2-normal.sh
+++ b/t/t0210-trace2-normal.sh
@@ -1,5 +1,10 @@
 #!/bin/sh
 
+# Turn off any inherited trace2 settings for this test.
+unset GIT_TR2 GIT_TR2_PERF GIT_TR2_EVENT
+unset GIT_TR2_BRIEF
+unset GIT_TR2_CONFIG_PARAMS
+
 test_description='test trace2 facility (normal target)'
 . ./test-lib.sh
 
@@ -15,11 +20,6 @@ PATH="$TTDIR:$PATH" && export PATH
 # Warning: So you may see extra lines in artifact files when
 # Warning: interactively debugging.
 
-# Turn off any inherited trace2 settings for this test.
-unset GIT_TR2 GIT_TR2_PERF GIT_TR2_EVENT
-unset GIT_TR2_BRIEF
-unset GIT_TR2_CONFIG_PARAMS
-
 V=$(git version | sed -e 's/^git version //') && export V
 
 # There are multiple trace2 targets: normal, perf, and event.
@@ -132,4 +132,43 @@ test_expect_success 'normal stream, error event' '
 	test_cmp expect actual
 '
 
+unset GIT_TR2_BRIEF
+
+# Now test without environment variables and get all Trace2 settings
+# from the global config.
+
+test_expect_success 'using global config, normal stream, return code 0' '
+	test_when_finished "rm trace.normal actual expect" &&
+	test_config_global trace2.normalBrief 1 &&
+	test_config_global trace2.normalTarget "$(pwd)/trace.normal" &&
+	test-tool trace2 001return 0 &&
+	perl "$TEST_DIRECTORY/t0210/scrub_normal.perl" <trace.normal >actual &&
+	cat >expect <<-EOF &&
+		version $V
+		start _EXE_ trace2 001return 0
+		cmd_name trace2 (trace2)
+		exit elapsed:_TIME_ code:0
+		atexit elapsed:_TIME_ code:0
+	EOF
+	test_cmp expect actual
+'
+
+test_expect_success 'using global config with include' '
+	test_when_finished "rm trace.normal actual expect real.gitconfig" &&
+	test_config_global trace2.normalBrief 1 &&
+	test_config_global trace2.normalTarget "$(pwd)/trace.normal" &&
+	mv "$(pwd)/.gitconfig" "$(pwd)/real.gitconfig" &&
+	test_config_global include.path "$(pwd)/real.gitconfig" &&
+	test-tool trace2 001return 0 &&
+	perl "$TEST_DIRECTORY/t0210/scrub_normal.perl" <trace.normal >actual &&
+	cat >expect <<-EOF &&
+		version $V
+		start _EXE_ trace2 001return 0
+		cmd_name trace2 (trace2)
+		exit elapsed:_TIME_ code:0
+		atexit elapsed:_TIME_ code:0
+	EOF
+	test_cmp expect actual
+'
+
 test_done
diff --git a/t/t0211-trace2-perf.sh b/t/t0211-trace2-perf.sh
index c9694b29f7..2a90e56db3 100755
--- a/t/t0211-trace2-perf.sh
+++ b/t/t0211-trace2-perf.sh
@@ -1,5 +1,10 @@
 #!/bin/sh
 
+# Turn off any inherited trace2 settings for this test.
+unset GIT_TR2 GIT_TR2_PERF GIT_TR2_EVENT
+unset GIT_TR2_PERF_BRIEF
+unset GIT_TR2_CONFIG_PARAMS
+
 test_description='test trace2 facility (perf target)'
 . ./test-lib.sh
 
@@ -15,11 +20,6 @@ PATH="$TTDIR:$PATH" && export PATH
 # Warning: So you may see extra lines in artifact files when
 # Warning: interactively debugging.
 
-# Turn off any inherited trace2 settings for this test.
-unset GIT_TR2 GIT_TR2_PERF GIT_TR2_EVENT
-unset GIT_TR2_PERF_BRIEF
-unset GIT_TR2_CONFIG_PARAMS
-
 V=$(git version | sed -e 's/^git version //') && export V
 
 # There are multiple trace2 targets: normal, perf, and event.
@@ -150,4 +150,25 @@ test_expect_success 'perf stream, child processes' '
 	test_cmp expect actual
 '
 
+unset GIT_TR2_PERF_BRIEF
+
+# Now test without environment variables and get all Trace2 settings
+# from the global config.
+
+test_expect_success 'using global config, perf stream, return code 0' '
+	test_when_finished "rm trace.perf actual expect" &&
+	test_config_global trace2.perfBrief 1 &&
+	test_config_global trace2.perfTarget "$(pwd)/trace.perf" &&
+	test-tool trace2 001return 0 &&
+	perl "$TEST_DIRECTORY/t0211/scrub_perf.perl" <trace.perf >actual &&
+	cat >expect <<-EOF &&
+		d0|main|version|||||$V
+		d0|main|start||_T_ABS_|||_EXE_ trace2 001return 0
+		d0|main|cmd_name|||||trace2 (trace2)
+		d0|main|exit||_T_ABS_|||code:0
+		d0|main|atexit||_T_ABS_|||code:0
+	EOF
+	test_cmp expect actual
+'
+
 test_done
diff --git a/t/t0212-trace2-event.sh b/t/t0212-trace2-event.sh
index 028b6c5671..a3943561c3 100755
--- a/t/t0212-trace2-event.sh
+++ b/t/t0212-trace2-event.sh
@@ -1,5 +1,10 @@
 #!/bin/sh
 
+# Turn off any inherited trace2 settings for this test.
+unset GIT_TR2 GIT_TR2_PERF GIT_TR2_EVENT
+unset GIT_TR2_BARE
+unset GIT_TR2_CONFIG_PARAMS
+
 test_description='test trace2 facility'
 . ./test-lib.sh
 
@@ -17,11 +22,6 @@ PATH="$TTDIR:$PATH" && export PATH
 # Warning: So you may see extra lines in artifact files when
 # Warning: interactively debugging.
 
-# Turn off any inherited trace2 settings for this test.
-unset GIT_TR2 GIT_TR2_PERF GIT_TR2_EVENT
-unset GIT_TR2_BARE
-unset GIT_TR2_CONFIG_PARAMS
-
 V=$(git version | sed -e 's/^git version //') && export V
 
 # There are multiple trace2 targets: normal, perf, and event.
@@ -233,4 +233,36 @@ test_expect_success JSON_PP 'basic trace2_data' '
 	test_cmp expect actual
 '
 
+# Now test without environment variables and get all Trace2 settings
+# from the global config.
+
+test_expect_success JSON_PP 'using global config, event stream, error event' '
+	test_when_finished "rm trace.event actual expect" &&
+	test_config_global trace2.eventTarget "$(pwd)/trace.event" &&
+	test-tool trace2 003error "hello world" "this is a test" &&
+	perl "$TEST_DIRECTORY/t0212/parse_events.perl" <trace.event >actual &&
+	sed -e "s/^|//" >expect <<-EOF &&
+	|VAR1 = {
+	|  "_SID0_":{
+	|    "argv":[
+	|      "_EXE_",
+	|      "trace2",
+	|      "003error",
+	|      "hello world",
+	|      "this is a test"
+	|    ],
+	|    "errors":[
+	|      "%s",
+	|      "%s"
+	|    ],
+	|    "exit_code":0,
+	|    "hierarchy":"trace2",
+	|    "name":"trace2",
+	|    "version":"$V"
+	|  }
+	|};
+	EOF
+	test_cmp expect actual
+'
+
 test_done
diff --git a/trace2.c b/trace2.c
index 1c180062dd..490b3f071e 100644
--- a/trace2.c
+++ b/trace2.c
@@ -10,6 +10,7 @@
 #include "trace2/tr2_cmd_name.h"
 #include "trace2/tr2_dst.h"
 #include "trace2/tr2_sid.h"
+#include "trace2/tr2_sysenv.h"
 #include "trace2/tr2_tgt.h"
 #include "trace2/tr2_tls.h"
 
@@ -120,6 +121,7 @@ static void tr2main_atexit_handler(void)
 	tr2_sid_release();
 	tr2_cmd_name_release();
 	tr2_cfg_free_patterns();
+	tr2_sysenv_release();
 
 	trace2_enabled = 0;
 }
@@ -155,6 +157,8 @@ void trace2_initialize_fl(const char *file, int line)
 	if (trace2_enabled)
 		return;
 
+	tr2_sysenv_load();
+
 	if (!tr2_tgt_want_builtins())
 		return;
 	trace2_enabled = 1;
diff --git a/trace2.h b/trace2.h
index 8f89e70c44..894bfca7e0 100644
--- a/trace2.h
+++ b/trace2.h
@@ -38,7 +38,8 @@ void trace2_initialize_clock(void);
 
 /*
  * Initialize TRACE2 tracing facility if any of the builtin TRACE2
- * targets are enabled in the environment.  Emits a 'version' event.
+ * targets are enabled in the system config or the environment.
+ * Emits a 'version' event.
  *
  * Cleanup/Termination is handled automatically by a registered
  * atexit() routine.
@@ -125,10 +126,11 @@ void trace2_cmd_alias_fl(const char *file, int line, const char *alias,
  * Emit one or more 'def_param' events for "interesting" configuration
  * settings.
  *
- * The environment variable "GIT_TR2_CONFIG_PARAMS" can be set to a
- * list of patterns considered important.  For example:
- *
- *    GIT_TR2_CONFIG_PARAMS="core.*,remote.*.url"
+ * Use the TR2_SYSENV_CFG_PARAM setting to register a comma-separated
+ * list of patterns configured important.  For example:
+ *     git config --system trace2.configParams 'core.*,remote.*.url'
+ * or:
+ *     GIT_TR2_CONFIG_PARAMS=core.*,remote.*.url"
  *
  * Note: this routine does a read-only iteration on the config data
  * (using read_early_config()), so it must not be called until enough
diff --git a/trace2/tr2_cfg.c b/trace2/tr2_cfg.c
index b329921ac5..caa7f06948 100644
--- a/trace2/tr2_cfg.c
+++ b/trace2/tr2_cfg.c
@@ -1,8 +1,7 @@
 #include "cache.h"
 #include "config.h"
-#include "tr2_cfg.h"
-
-#define TR2_ENVVAR_CFG_PARAM "GIT_TR2_CONFIG_PARAMS"
+#include "trace2/tr2_cfg.h"
+#include "trace2/tr2_sysenv.h"
 
 static struct strbuf **tr2_cfg_patterns;
 static int tr2_cfg_count_patterns;
@@ -21,7 +20,7 @@ static int tr2_cfg_load_patterns(void)
 		return tr2_cfg_count_patterns;
 	tr2_cfg_loaded = 1;
 
-	envvar = getenv(TR2_ENVVAR_CFG_PARAM);
+	envvar = tr2_sysenv_get(TR2_SYSENV_CFG_PARAM);
 	if (!envvar || !*envvar)
 		return tr2_cfg_count_patterns;
 
diff --git a/trace2/tr2_dst.c b/trace2/tr2_dst.c
index fd490a43ad..575cd69aa9 100644
--- a/trace2/tr2_dst.c
+++ b/trace2/tr2_dst.c
@@ -1,5 +1,6 @@
 #include "cache.h"
 #include "trace2/tr2_dst.h"
+#include "trace2/tr2_sysenv.h"
 
 /*
  * If a Trace2 target cannot be opened for writing, we should issue a
@@ -7,17 +8,13 @@
  * or socket and beyond the user's control -- especially since every
  * git command (and sub-command) will print the message.  So we silently
  * eat these warnings and just discard the trace data.
- *
- * Enable the following environment variable to see these warnings.
  */
-#define TR2_ENVVAR_DST_DEBUG "GIT_TR2_DST_DEBUG"
-
 static int tr2_dst_want_warning(void)
 {
 	static int tr2env_dst_debug = -1;
 
 	if (tr2env_dst_debug == -1) {
-		const char *env_value = getenv(TR2_ENVVAR_DST_DEBUG);
+		const char *env_value = tr2_sysenv_get(TR2_SYSENV_DST_DEBUG);
 		if (!env_value || !*env_value)
 			tr2env_dst_debug = 0;
 		else
@@ -42,7 +39,9 @@ static int tr2_dst_try_path(struct tr2_dst *dst, const char *tgt_value)
 	if (fd == -1) {
 		if (tr2_dst_want_warning())
 			warning("trace2: could not open '%s' for '%s' tracing: %s",
-				tgt_value, dst->env_var_name, strerror(errno));
+				tgt_value,
+				tr2_sysenv_display_name(dst->sysenv_var),
+				strerror(errno));
 
 		tr2_dst_trace_disable(dst);
 		return 0;
@@ -116,7 +115,7 @@ static int tr2_dst_try_unix_domain_socket(struct tr2_dst *dst,
 	if (!path || !*path) {
 		if (tr2_dst_want_warning())
 			warning("trace2: invalid AF_UNIX value '%s' for '%s' tracing",
-				tgt_value, dst->env_var_name);
+				tgt_value, tr2_sysenv_display_name(dst->sysenv_var));
 
 		tr2_dst_trace_disable(dst);
 		return 0;
@@ -126,7 +125,7 @@ static int tr2_dst_try_unix_domain_socket(struct tr2_dst *dst,
 	    strlen(path) >= sizeof(((struct sockaddr_un *)0)->sun_path)) {
 		if (tr2_dst_want_warning())
 			warning("trace2: invalid AF_UNIX path '%s' for '%s' tracing",
-				path, dst->env_var_name);
+				path, tr2_sysenv_display_name(dst->sysenv_var));
 
 		tr2_dst_trace_disable(dst);
 		return 0;
@@ -148,7 +147,7 @@ static int tr2_dst_try_unix_domain_socket(struct tr2_dst *dst,
 error:
 	if (tr2_dst_want_warning())
 		warning("trace2: could not connect to socket '%s' for '%s' tracing: %s",
-			path, dst->env_var_name, strerror(e));
+			path, tr2_sysenv_display_name(dst->sysenv_var), strerror(e));
 
 	tr2_dst_trace_disable(dst);
 	return 0;
@@ -168,7 +167,7 @@ static void tr2_dst_malformed_warning(struct tr2_dst *dst,
 	struct strbuf buf = STRBUF_INIT;
 
 	strbuf_addf(&buf, "trace2: unknown value for '%s': '%s'",
-		    dst->env_var_name, tgt_value);
+		    tr2_sysenv_display_name(dst->sysenv_var), tgt_value);
 	warning("%s", buf.buf);
 
 	strbuf_release(&buf);
@@ -184,7 +183,7 @@ int tr2_dst_get_trace_fd(struct tr2_dst *dst)
 
 	dst->initialized = 1;
 
-	tgt_value = getenv(dst->env_var_name);
+	tgt_value = tr2_sysenv_get(dst->sysenv_var);
 
 	if (!tgt_value || !strcmp(tgt_value, "") || !strcmp(tgt_value, "0") ||
 	    !strcasecmp(tgt_value, "false")) {
@@ -246,7 +245,8 @@ void tr2_dst_write_line(struct tr2_dst *dst, struct strbuf *buf_line)
 		return;
 
 	if (tr2_dst_want_warning())
-		warning("unable to write trace to '%s': %s", dst->env_var_name,
+		warning("unable to write trace to '%s': %s",
+			tr2_sysenv_display_name(dst->sysenv_var),
 			strerror(errno));
 	tr2_dst_trace_disable(dst);
 }
diff --git a/trace2/tr2_dst.h b/trace2/tr2_dst.h
index 9a64f05b02..3adf3bac13 100644
--- a/trace2/tr2_dst.h
+++ b/trace2/tr2_dst.h
@@ -2,9 +2,10 @@
 #define TR2_DST_H
 
 struct strbuf;
+#include "trace2/tr2_sysenv.h"
 
 struct tr2_dst {
-	const char *const env_var_name;
+	enum tr2_sysenv_variable sysenv_var;
 	int fd;
 	unsigned int initialized : 1;
 	unsigned int need_close : 1;
diff --git a/trace2/tr2_sysenv.c b/trace2/tr2_sysenv.c
new file mode 100644
index 0000000000..9025b86303
--- /dev/null
+++ b/trace2/tr2_sysenv.c
@@ -0,0 +1,127 @@
+#include "cache.h"
+#include "config.h"
+#include "dir.h"
+#include "tr2_sysenv.h"
+
+/*
+ * Each entry represents a trace2 setting.
+ * See Documentation/technical/api-trace2.txt
+ */
+struct tr2_sysenv_entry {
+	const char *env_var_name;
+	const char *git_config_name;
+
+	char *value;
+	unsigned int getenv_called : 1;
+};
+
+/*
+ * This table must match "enum tr2_sysenv_variable" in tr2_sysenv.h.
+ *
+ * The strings in this table are constant and must match the published
+ * config and environment variable names as described in the documentation.
+ *
+ * We do not define entries for the GIT_TR2_PARENT_* environment
+ * variables because they are transient and used to pass information
+ * from parent to child git processes, rather than settings.
+ */
+/* clang-format off */
+static struct tr2_sysenv_entry tr2_sysenv_settings[] = {
+	[TR2_SYSENV_CFG_PARAM]     = { "GIT_TR2_CONFIG_PARAMS",
+				       "trace2.configparams" },
+
+	[TR2_SYSENV_DST_DEBUG]     = { "GIT_TR2_DST_DEBUG",
+				       "trace2.destinationdebug" },
+
+	[TR2_SYSENV_NORMAL]        = { "GIT_TR2",
+				       "trace2.normaltarget" },
+	[TR2_SYSENV_NORMAL_BRIEF]  = { "GIT_TR2_BRIEF",
+				       "trace2.normalbrief" },
+
+	[TR2_SYSENV_EVENT]         = { "GIT_TR2_EVENT",
+				       "trace2.eventtarget" },
+	[TR2_SYSENV_EVENT_BRIEF]   = { "GIT_TR2_EVENT_BRIEF",
+				       "trace2.eventbrief" },
+	[TR2_SYSENV_EVENT_NESTING] = { "GIT_TR2_EVENT_NESTING",
+				       "trace2.eventnesting" },
+
+	[TR2_SYSENV_PERF]          = { "GIT_TR2_PERF",
+				       "trace2.perftarget" },
+	[TR2_SYSENV_PERF_BRIEF]    = { "GIT_TR2_PERF_BRIEF",
+				       "trace2.perfbrief" },
+};
+/* clang-format on */
+
+static int tr2_sysenv_cb(const char *key, const char *value, void *d)
+{
+	int k;
+
+	if (!starts_with(key, "trace2."))
+		return 0;
+
+	for (k = 0; k < ARRAY_SIZE(tr2_sysenv_settings); k++) {
+		if (!strcmp(key, tr2_sysenv_settings[k].git_config_name)) {
+			free(tr2_sysenv_settings[k].value);
+			tr2_sysenv_settings[k].value = xstrdup(value);
+			return 0;
+		}
+	}
+
+	return 0;
+}
+
+/*
+ * Load Trace2 settings from the system config (usually "/etc/gitconfig"
+ * unless we were built with a runtime-prefix).  These are intended to
+ * define the default values for Trace2 as requested by the administrator.
+ *
+ * Then override with the Trace2 settings from the global config.
+ */
+void tr2_sysenv_load(void)
+{
+	if (ARRAY_SIZE(tr2_sysenv_settings) != TR2_SYSENV_MUST_BE_LAST)
+		BUG("tr2_sysenv_settings size is wrong");
+
+	read_very_early_config(tr2_sysenv_cb, NULL);
+}
+
+/*
+ * Return the value for the requested Trace2 setting from these sources:
+ * the system config, the global config, and the environment.
+ */
+const char *tr2_sysenv_get(enum tr2_sysenv_variable var)
+{
+	if (var >= TR2_SYSENV_MUST_BE_LAST)
+		BUG("tr2_sysenv_get invalid var '%d'", var);
+
+	if (!tr2_sysenv_settings[var].getenv_called) {
+		const char *v = getenv(tr2_sysenv_settings[var].env_var_name);
+		if (v && *v) {
+			free(tr2_sysenv_settings[var].value);
+			tr2_sysenv_settings[var].value = xstrdup(v);
+		}
+		tr2_sysenv_settings[var].getenv_called = 1;
+	}
+
+	return tr2_sysenv_settings[var].value;
+}
+
+/*
+ * Return a friendly name for this setting that is suitable for printing
+ * in an error messages.
+ */
+const char *tr2_sysenv_display_name(enum tr2_sysenv_variable var)
+{
+	if (var >= TR2_SYSENV_MUST_BE_LAST)
+		BUG("tr2_sysenv_get invalid var '%d'", var);
+
+	return tr2_sysenv_settings[var].env_var_name;
+}
+
+void tr2_sysenv_release(void)
+{
+	int k;
+
+	for (k = 0; k < ARRAY_SIZE(tr2_sysenv_settings); k++)
+		free(tr2_sysenv_settings[k].value);
+}
diff --git a/trace2/tr2_sysenv.h b/trace2/tr2_sysenv.h
new file mode 100644
index 0000000000..369b20bd87
--- /dev/null
+++ b/trace2/tr2_sysenv.h
@@ -0,0 +1,36 @@
+#ifndef TR2_SYSENV_H
+#define TR2_SYSENV_H
+
+/*
+ * The Trace2 settings that can be loaded from /etc/gitconfig
+ * and/or user environment variables.
+ *
+ * Note that this set does not contain any of the transient
+ * environment variables used to pass information from parent
+ * to child git processes, such "GIT_TR2_PARENT_SID".
+ */
+enum tr2_sysenv_variable {
+	TR2_SYSENV_CFG_PARAM = 0,
+
+	TR2_SYSENV_DST_DEBUG,
+
+	TR2_SYSENV_NORMAL,
+	TR2_SYSENV_NORMAL_BRIEF,
+
+	TR2_SYSENV_EVENT,
+	TR2_SYSENV_EVENT_BRIEF,
+	TR2_SYSENV_EVENT_NESTING,
+
+	TR2_SYSENV_PERF,
+	TR2_SYSENV_PERF_BRIEF,
+
+	TR2_SYSENV_MUST_BE_LAST
+};
+
+void tr2_sysenv_load(void);
+
+const char *tr2_sysenv_get(enum tr2_sysenv_variable);
+const char *tr2_sysenv_display_name(enum tr2_sysenv_variable var);
+void tr2_sysenv_release(void);
+
+#endif /* TR2_SYSENV_H */
diff --git a/trace2/tr2_tgt_event.c b/trace2/tr2_tgt_event.c
index 89a4d3ae9a..48d9193b2c 100644
--- a/trace2/tr2_tgt_event.c
+++ b/trace2/tr2_tgt_event.c
@@ -6,10 +6,11 @@
 #include "trace2/tr2_dst.h"
 #include "trace2/tr2_tbuf.h"
 #include "trace2/tr2_sid.h"
+#include "trace2/tr2_sysenv.h"
 #include "trace2/tr2_tgt.h"
 #include "trace2/tr2_tls.h"
 
-static struct tr2_dst tr2dst_event = { "GIT_TR2_EVENT", 0, 0, 0 };
+static struct tr2_dst tr2dst_event = { TR2_SYSENV_EVENT, 0, 0, 0 };
 
 /*
  * The version number of the JSON data generated by the EVENT target
@@ -28,37 +29,36 @@ static struct tr2_dst tr2dst_event = { "GIT_TR2_EVENT", 0, 0, 0 };
  * are primarily intended for the performance target during debugging.
  *
  * Some of the outer-most messages, however, may be of interest to the
- * event target.  Set this environment variable to a larger integer for
- * more detail in the event target.
+ * event target.  Use the TR2_SYSENV_EVENT_NESTING setting to increase
+ * region details in the event target.
  */
-#define TR2_ENVVAR_EVENT_NESTING "GIT_TR2_EVENT_NESTING"
-static int tr2env_event_nesting_wanted = 2;
+static int tr2env_event_max_nesting_levels = 2;
 
 /*
- * Set this environment variable to true to omit the <time>, <file>, and
+ * Use the TR2_SYSENV_EVENT_BRIEF to omit the <time>, <file>, and
  * <line> fields from most events.
  */
-#define TR2_ENVVAR_EVENT_BRIEF "GIT_TR2_EVENT_BRIEF"
-static int tr2env_event_brief;
+static int tr2env_event_be_brief;
 
 static int fn_init(void)
 {
 	int want = tr2_dst_trace_want(&tr2dst_event);
-	int want_nesting;
+	int max_nesting;
 	int want_brief;
-	char *nesting;
-	char *brief;
+	const char *nesting;
+	const char *brief;
 
 	if (!want)
 		return want;
 
-	nesting = getenv(TR2_ENVVAR_EVENT_NESTING);
-	if (nesting && ((want_nesting = atoi(nesting)) > 0))
-		tr2env_event_nesting_wanted = want_nesting;
+	nesting = tr2_sysenv_get(TR2_SYSENV_EVENT_NESTING);
+	if (nesting && *nesting && ((max_nesting = atoi(nesting)) > 0))
+		tr2env_event_max_nesting_levels = max_nesting;
 
-	brief = getenv(TR2_ENVVAR_EVENT_BRIEF);
-	if (brief && ((want_brief = atoi(brief)) > 0))
-		tr2env_event_brief = want_brief;
+	brief = tr2_sysenv_get(TR2_SYSENV_EVENT_BRIEF);
+	if (brief && *brief &&
+	    ((want_brief = git_parse_maybe_bool(brief)) != -1))
+		tr2env_event_be_brief = want_brief;
 
 	return want;
 }
@@ -92,13 +92,13 @@ static void event_fmt_prepare(const char *event_name, const char *file,
 	/*
 	 * In brief mode, only emit <time> on these 2 event types.
 	 */
-	if (!tr2env_event_brief || !strcmp(event_name, "version") ||
+	if (!tr2env_event_be_brief || !strcmp(event_name, "version") ||
 	    !strcmp(event_name, "atexit")) {
 		tr2_tbuf_utc_time(&tb_now);
 		jw_object_string(jw, "time", tb_now.buf);
 	}
 
-	if (!tr2env_event_brief && file && *file) {
+	if (!tr2env_event_be_brief && file && *file) {
 		jw_object_string(jw, "file", file);
 		jw_object_intmax(jw, "line", line);
 	}
@@ -459,7 +459,7 @@ static void fn_region_enter_printf_va_fl(const char *file, int line,
 {
 	const char *event_name = "region_enter";
 	struct tr2tls_thread_ctx *ctx = tr2tls_get_self();
-	if (ctx->nr_open_regions <= tr2env_event_nesting_wanted) {
+	if (ctx->nr_open_regions <= tr2env_event_max_nesting_levels) {
 		struct json_writer jw = JSON_WRITER_INIT;
 
 		jw_object_begin(&jw, 0);
@@ -484,7 +484,7 @@ static void fn_region_leave_printf_va_fl(
 {
 	const char *event_name = "region_leave";
 	struct tr2tls_thread_ctx *ctx = tr2tls_get_self();
-	if (ctx->nr_open_regions <= tr2env_event_nesting_wanted) {
+	if (ctx->nr_open_regions <= tr2env_event_max_nesting_levels) {
 		struct json_writer jw = JSON_WRITER_INIT;
 		double t_rel = (double)us_elapsed_region / 1000000.0;
 
@@ -511,7 +511,7 @@ static void fn_data_fl(const char *file, int line, uint64_t us_elapsed_absolute,
 {
 	const char *event_name = "data";
 	struct tr2tls_thread_ctx *ctx = tr2tls_get_self();
-	if (ctx->nr_open_regions <= tr2env_event_nesting_wanted) {
+	if (ctx->nr_open_regions <= tr2env_event_max_nesting_levels) {
 		struct json_writer jw = JSON_WRITER_INIT;
 		double t_abs = (double)us_elapsed_absolute / 1000000.0;
 		double t_rel = (double)us_elapsed_region / 1000000.0;
@@ -539,7 +539,7 @@ static void fn_data_json_fl(const char *file, int line,
 {
 	const char *event_name = "data_json";
 	struct tr2tls_thread_ctx *ctx = tr2tls_get_self();
-	if (ctx->nr_open_regions <= tr2env_event_nesting_wanted) {
+	if (ctx->nr_open_regions <= tr2env_event_max_nesting_levels) {
 		struct json_writer jw = JSON_WRITER_INIT;
 		double t_abs = (double)us_elapsed_absolute / 1000000.0;
 		double t_rel = (double)us_elapsed_region / 1000000.0;
diff --git a/trace2/tr2_tgt_normal.c b/trace2/tr2_tgt_normal.c
index 57f3e18f5b..1ce6f97863 100644
--- a/trace2/tr2_tgt_normal.c
+++ b/trace2/tr2_tgt_normal.c
@@ -4,20 +4,20 @@
 #include "quote.h"
 #include "version.h"
 #include "trace2/tr2_dst.h"
+#include "trace2/tr2_sysenv.h"
 #include "trace2/tr2_tbuf.h"
 #include "trace2/tr2_tgt.h"
 #include "trace2/tr2_tls.h"
 
-static struct tr2_dst tr2dst_normal = { "GIT_TR2", 0, 0, 0 };
+static struct tr2_dst tr2dst_normal = { TR2_SYSENV_NORMAL, 0, 0, 0 };
 
 /*
- * Set this environment variable to true to omit the "<time> <file>:<line>"
+ * Use the TR2_SYSENV_NORMAL_BRIEF setting to omit the "<time> <file>:<line>"
  * fields from each line written to the builtin normal target.
  *
  * Unit tests may want to use this to help with testing.
  */
-#define TR2_ENVVAR_NORMAL_BRIEF "GIT_TR2_BRIEF"
-static int tr2env_normal_brief;
+static int tr2env_normal_be_brief;
 
 #define TR2FMT_NORMAL_FL_WIDTH (50)
 
@@ -25,15 +25,15 @@ static int fn_init(void)
 {
 	int want = tr2_dst_trace_want(&tr2dst_normal);
 	int want_brief;
-	char *brief;
+	const char *brief;
 
 	if (!want)
 		return want;
 
-	brief = getenv(TR2_ENVVAR_NORMAL_BRIEF);
+	brief = tr2_sysenv_get(TR2_SYSENV_NORMAL_BRIEF);
 	if (brief && *brief &&
 	    ((want_brief = git_parse_maybe_bool(brief)) != -1))
-		tr2env_normal_brief = want_brief;
+		tr2env_normal_be_brief = want_brief;
 
 	return want;
 }
@@ -47,7 +47,7 @@ static void normal_fmt_prepare(const char *file, int line, struct strbuf *buf)
 {
 	strbuf_setlen(buf, 0);
 
-	if (!tr2env_normal_brief) {
+	if (!tr2env_normal_be_brief) {
 		struct tr2_tbuf tb_now;
 
 		tr2_tbuf_local_time(&tb_now);
diff --git a/trace2/tr2_tgt_perf.c b/trace2/tr2_tgt_perf.c
index 9c3b4d8a0f..328d2234bd 100644
--- a/trace2/tr2_tgt_perf.c
+++ b/trace2/tr2_tgt_perf.c
@@ -6,20 +6,20 @@
 #include "json-writer.h"
 #include "trace2/tr2_dst.h"
 #include "trace2/tr2_sid.h"
+#include "trace2/tr2_sysenv.h"
 #include "trace2/tr2_tbuf.h"
 #include "trace2/tr2_tgt.h"
 #include "trace2/tr2_tls.h"
 
-static struct tr2_dst tr2dst_perf = { "GIT_TR2_PERF", 0, 0, 0 };
+static struct tr2_dst tr2dst_perf = { TR2_SYSENV_PERF, 0, 0, 0 };
 
 /*
- * Set this environment variable to true to omit the "<time> <file>:<line>"
+ * Use TR2_SYSENV_PERF_BRIEF to omit the "<time> <file>:<line>"
  * fields from each line written to the builtin performance target.
  *
  * Unit tests may want to use this to help with testing.
  */
-#define TR2_ENVVAR_PERF_BRIEF "GIT_TR2_PERF_BRIEF"
-static int tr2env_perf_brief;
+static int tr2env_perf_be_brief;
 
 #define TR2FMT_PERF_FL_WIDTH (50)
 #define TR2FMT_PERF_MAX_EVENT_NAME (12)
@@ -36,17 +36,17 @@ static int fn_init(void)
 {
 	int want = tr2_dst_trace_want(&tr2dst_perf);
 	int want_brief;
-	char *brief;
+	const char *brief;
 
 	if (!want)
 		return want;
 
 	strbuf_addchars(&dots, '.', TR2_DOTS_BUFFER_SIZE);
 
-	brief = getenv(TR2_ENVVAR_PERF_BRIEF);
+	brief = tr2_sysenv_get(TR2_SYSENV_PERF_BRIEF);
 	if (brief && *brief &&
 	    ((want_brief = git_parse_maybe_bool(brief)) != -1))
-		tr2env_perf_brief = want_brief;
+		tr2env_perf_be_brief = want_brief;
 
 	return want;
 }
@@ -77,7 +77,7 @@ static void perf_fmt_prepare(const char *event_name,
 
 	strbuf_setlen(buf, 0);
 
-	if (!tr2env_perf_brief) {
+	if (!tr2env_perf_be_brief) {
 		struct tr2_tbuf tb_now;
 
 		tr2_tbuf_local_time(&tb_now);
-- 
gitgitgadget


^ permalink raw reply	[flat|nested] 68+ messages in thread

* [PATCH v3 07/10] trace2: report peak memory usage of the process
  2019-04-11 15:18   ` [PATCH v3 00/10] " Jeff Hostetler via GitGitGadget
                       ` (5 preceding siblings ...)
  2019-04-11 15:18     ` [PATCH v3 06/10] trace2: use system/global config for default trace2 settings Jeff Hostetler via GitGitGadget
@ 2019-04-11 15:18     ` Jeff Hostetler via GitGitGadget
  2019-04-11 15:18     ` [PATCH v3 08/10] trace2: clarify UTC datetime formatting Jeff Hostetler via GitGitGadget
                       ` (4 subsequent siblings)
  11 siblings, 0 replies; 68+ messages in thread
From: Jeff Hostetler via GitGitGadget @ 2019-04-11 15:18 UTC (permalink / raw)
  To: git
  Cc: gitster, peff, jrnieder, steadmon, avarab, Junio C Hamano,
	Jeff Hostetler

From: Jeff Hostetler <jeffhost@microsoft.com>

Teach Windows version of git to report peak memory usage
during exit() processing.

Signed-off-by: Jeff Hostetler <jeffhost@microsoft.com>
---
 common-main.c                            |  2 +-
 compat/win32/trace2_win32_process_info.c | 50 ++++++++++++++++++++++--
 trace2.c                                 |  2 +
 trace2.h                                 | 14 +++++--
 4 files changed, 60 insertions(+), 8 deletions(-)

diff --git a/common-main.c b/common-main.c
index 299ca62a72..582a7b1886 100644
--- a/common-main.c
+++ b/common-main.c
@@ -41,7 +41,7 @@ int main(int argc, const char **argv)
 
 	trace2_initialize();
 	trace2_cmd_start(argv);
-	trace2_collect_process_info();
+	trace2_collect_process_info(TRACE2_PROCESS_INFO_STARTUP);
 
 	git_setup_gettext();
 
diff --git a/compat/win32/trace2_win32_process_info.c b/compat/win32/trace2_win32_process_info.c
index 52bd62034b..2a514caed9 100644
--- a/compat/win32/trace2_win32_process_info.c
+++ b/compat/win32/trace2_win32_process_info.c
@@ -1,5 +1,6 @@
 #include "../../cache.h"
 #include "../../json-writer.h"
+#include "lazyload.h"
 #include <Psapi.h>
 #include <tlHelp32.h>
 
@@ -137,11 +138,54 @@ static void get_is_being_debugged(void)
 				   "windows/debugger_present", 1);
 }
 
-void trace2_collect_process_info(void)
+/*
+ * Emit JSON data with the peak memory usage of the current process.
+ */
+static void get_peak_memory_info(void)
+{
+	DECLARE_PROC_ADDR(psapi.dll, BOOL, GetProcessMemoryInfo,
+			  HANDLE, PPROCESS_MEMORY_COUNTERS, DWORD);
+
+	if (INIT_PROC_ADDR(GetProcessMemoryInfo)) {
+		PROCESS_MEMORY_COUNTERS pmc;
+
+		if (GetProcessMemoryInfo(GetCurrentProcess(), &pmc,
+					 sizeof(pmc))) {
+			struct json_writer jw = JSON_WRITER_INIT;
+
+			jw_object_begin(&jw, 0);
+
+#define KV(kv) #kv, (intmax_t)pmc.kv
+
+			jw_object_intmax(&jw, KV(PageFaultCount));
+			jw_object_intmax(&jw, KV(PeakWorkingSetSize));
+			jw_object_intmax(&jw, KV(PeakPagefileUsage));
+
+			jw_end(&jw);
+
+			trace2_data_json("process", the_repository,
+					 "windows/memory", &jw);
+			jw_release(&jw);
+		}
+	}
+}
+
+void trace2_collect_process_info(enum trace2_process_info_reason reason)
 {
 	if (!trace2_is_enabled())
 		return;
 
-	get_is_being_debugged();
-	get_ancestry();
+	switch (reason) {
+	case TRACE2_PROCESS_INFO_STARTUP:
+		get_is_being_debugged();
+		get_ancestry();
+		return;
+
+	case TRACE2_PROCESS_INFO_EXIT:
+		get_peak_memory_info();
+		return;
+
+	default:
+		BUG("trace2_collect_process_info: unknown reason '%d'", reason);
+	}
 }
diff --git a/trace2.c b/trace2.c
index 490b3f071e..6baa65cdf9 100644
--- a/trace2.c
+++ b/trace2.c
@@ -213,6 +213,8 @@ int trace2_cmd_exit_fl(const char *file, int line, int code)
 	if (!trace2_enabled)
 		return code;
 
+	trace2_collect_process_info(TRACE2_PROCESS_INFO_EXIT);
+
 	tr2main_exit_code = code;
 
 	us_now = getnanotime() / 1000;
diff --git a/trace2.h b/trace2.h
index 894bfca7e0..888531eb08 100644
--- a/trace2.h
+++ b/trace2.h
@@ -391,13 +391,19 @@ void trace2_printf(const char *fmt, ...);
  * Optional platform-specific code to dump information about the
  * current and any parent process(es).  This is intended to allow
  * post-processors to know who spawned this git instance and anything
- * else the platform may be able to tell us about the current process.
+ * else that the platform may be able to tell us about the current process.
  */
+
+enum trace2_process_info_reason {
+	TRACE2_PROCESS_INFO_STARTUP,
+	TRACE2_PROCESS_INFO_EXIT,
+};
+
 #if defined(GIT_WINDOWS_NATIVE)
-void trace2_collect_process_info(void);
+void trace2_collect_process_info(enum trace2_process_info_reason reason);
 #else
-#define trace2_collect_process_info() \
-	do {                          \
+#define trace2_collect_process_info(reason) \
+	do {                                \
 	} while (0)
 #endif
 
-- 
gitgitgadget


^ permalink raw reply	[flat|nested] 68+ messages in thread

* [PATCH v3 08/10] trace2: clarify UTC datetime formatting
  2019-04-11 15:18   ` [PATCH v3 00/10] " Jeff Hostetler via GitGitGadget
                       ` (6 preceding siblings ...)
  2019-04-11 15:18     ` [PATCH v3 07/10] trace2: report peak memory usage of the process Jeff Hostetler via GitGitGadget
@ 2019-04-11 15:18     ` Jeff Hostetler via GitGitGadget
  2019-04-11 15:18     ` [PATCH v3 10/10] trace2: update docs to describe system/global config settings Jeff Hostetler via GitGitGadget
                       ` (3 subsequent siblings)
  11 siblings, 0 replies; 68+ messages in thread
From: Jeff Hostetler via GitGitGadget @ 2019-04-11 15:18 UTC (permalink / raw)
  To: git
  Cc: gitster, peff, jrnieder, steadmon, avarab, Junio C Hamano,
	Jeff Hostetler

From: Jeff Hostetler <jeffhost@microsoft.com>

Update tr2_tbuf_utc_datetime to generate extended UTC format.
Update tr2_tgt_event target to use extended format in 'time' columns.

Signed-off-by: Jeff Hostetler <jeffhost@microsoft.com>
---
 Documentation/technical/api-trace2.txt | 12 ++++++------
 trace2/tr2_tbuf.c                      |  4 ++--
 trace2/tr2_tbuf.h                      |  4 ++--
 trace2/tr2_tgt_event.c                 |  2 +-
 4 files changed, 11 insertions(+), 11 deletions(-)

diff --git a/Documentation/technical/api-trace2.txt b/Documentation/technical/api-trace2.txt
index baaa1153bb..cdc00bcc5d 100644
--- a/Documentation/technical/api-trace2.txt
+++ b/Documentation/technical/api-trace2.txt
@@ -78,11 +78,11 @@ git version 2.20.1.155.g426c96fcdb
 +
 ------------
 $ cat ~/log.event
-{"event":"version","sid":"1547659722619736-11614","thread":"main","time":"2019-01-16 17:28:42.620713","file":"common-main.c","line":38,"evt":"1","exe":"2.20.1.155.g426c96fcdb"}
-{"event":"start","sid":"1547659722619736-11614","thread":"main","time":"2019-01-16 17:28:42.621027","file":"common-main.c","line":39,"t_abs":0.001173,"argv":["git","version"]}
-{"event":"cmd_name","sid":"1547659722619736-11614","thread":"main","time":"2019-01-16 17:28:42.621122","file":"git.c","line":432,"name":"version","hierarchy":"version"}
-{"event":"exit","sid":"1547659722619736-11614","thread":"main","time":"2019-01-16 17:28:42.621236","file":"git.c","line":662,"t_abs":0.001227,"code":0}
-{"event":"atexit","sid":"1547659722619736-11614","thread":"main","time":"2019-01-16 17:28:42.621268","file":"trace2/tr2_tgt_event.c","line":163,"t_abs":0.001265,"code":0}
+{"event":"version","sid":"1547659722619736-11614","thread":"main","time":"2019-01-16T17:28:42.620713Z","file":"common-main.c","line":38,"evt":"1","exe":"2.20.1.155.g426c96fcdb"}
+{"event":"start","sid":"1547659722619736-11614","thread":"main","time":"2019-01-16T17:28:42.621027Z","file":"common-main.c","line":39,"t_abs":0.001173,"argv":["git","version"]}
+{"event":"cmd_name","sid":"1547659722619736-11614","thread":"main","time":"2019-01-16T17:28:42.621122Z","file":"git.c","line":432,"name":"version","hierarchy":"version"}
+{"event":"exit","sid":"1547659722619736-11614","thread":"main","time":"2019-01-16T17:28:42.621236Z","file":"git.c","line":662,"t_abs":0.001227,"code":0}
+{"event":"atexit","sid":"1547659722619736-11614","thread":"main","time":"2019-01-16T17:28:42.621268Z","file":"trace2/tr2_tgt_event.c","line":163,"t_abs":0.001265,"code":0}
 ------------
 
 == Enabling a Target
@@ -542,7 +542,7 @@ The following key/value pairs are common to all events:
 	"event":"version",
 	"sid":"1547659722619736-11614",
 	"thread":"main",
-	"time":"2019-01-16 17:28:42.620713",
+	"time":"2019-01-16T17:28:42.620713Z",
 	"file":"common-main.c",
 	"line":38,
 	...
diff --git a/trace2/tr2_tbuf.c b/trace2/tr2_tbuf.c
index 0844910423..eb1b240d8a 100644
--- a/trace2/tr2_tbuf.c
+++ b/trace2/tr2_tbuf.c
@@ -15,7 +15,7 @@ void tr2_tbuf_local_time(struct tr2_tbuf *tb)
 		  tm.tm_min, tm.tm_sec, (long)tv.tv_usec);
 }
 
-void tr2_tbuf_utc_time(struct tr2_tbuf *tb)
+void tr2_tbuf_utc_datetime_extended(struct tr2_tbuf *tb)
 {
 	struct timeval tv;
 	struct tm tm;
@@ -26,7 +26,7 @@ void tr2_tbuf_utc_time(struct tr2_tbuf *tb)
 	gmtime_r(&secs, &tm);
 
 	xsnprintf(tb->buf, sizeof(tb->buf),
-		  "%4d-%02d-%02d %02d:%02d:%02d.%06ld", tm.tm_year + 1900,
+		  "%4d-%02d-%02dT%02d:%02d:%02d.%06ldZ", tm.tm_year + 1900,
 		  tm.tm_mon + 1, tm.tm_mday, tm.tm_hour, tm.tm_min, tm.tm_sec,
 		  (long)tv.tv_usec);
 }
diff --git a/trace2/tr2_tbuf.h b/trace2/tr2_tbuf.h
index 9cdefa3957..2a1d173ff2 100644
--- a/trace2/tr2_tbuf.h
+++ b/trace2/tr2_tbuf.h
@@ -16,8 +16,8 @@ struct tr2_tbuf {
 void tr2_tbuf_local_time(struct tr2_tbuf *tb);
 
 /*
- * Fill buffer with formatted UTC time string.
+ * Fill buffer with formatted UTC datatime string.
  */
-void tr2_tbuf_utc_time(struct tr2_tbuf *tb);
+void tr2_tbuf_utc_datetime_extended(struct tr2_tbuf *tb);
 
 #endif /* TR2_TBUF_H */
diff --git a/trace2/tr2_tgt_event.c b/trace2/tr2_tgt_event.c
index 48d9193b2c..2c97cf54be 100644
--- a/trace2/tr2_tgt_event.c
+++ b/trace2/tr2_tgt_event.c
@@ -94,7 +94,7 @@ static void event_fmt_prepare(const char *event_name, const char *file,
 	 */
 	if (!tr2env_event_be_brief || !strcmp(event_name, "version") ||
 	    !strcmp(event_name, "atexit")) {
-		tr2_tbuf_utc_time(&tb_now);
+		tr2_tbuf_utc_datetime_extended(&tb_now);
 		jw_object_string(jw, "time", tb_now.buf);
 	}
 
-- 
gitgitgadget


^ permalink raw reply	[flat|nested] 68+ messages in thread

* [PATCH v3 10/10] trace2: update docs to describe system/global config settings
  2019-04-11 15:18   ` [PATCH v3 00/10] " Jeff Hostetler via GitGitGadget
                       ` (7 preceding siblings ...)
  2019-04-11 15:18     ` [PATCH v3 08/10] trace2: clarify UTC datetime formatting Jeff Hostetler via GitGitGadget
@ 2019-04-11 15:18     ` Jeff Hostetler via GitGitGadget
  2019-04-11 15:18     ` [PATCH v3 09/10] trace2: make SIDs more unique Jeff Hostetler via GitGitGadget
                       ` (2 subsequent siblings)
  11 siblings, 0 replies; 68+ messages in thread
From: Jeff Hostetler via GitGitGadget @ 2019-04-11 15:18 UTC (permalink / raw)
  To: git
  Cc: gitster, peff, jrnieder, steadmon, avarab, Junio C Hamano,
	Jeff Hostetler

From: Jeff Hostetler <jeffhost@microsoft.com>

Signed-off-by: Jeff Hostetler <jeffhost@microsoft.com>
---
 Documentation/config.txt               |   2 +
 Documentation/config/trace2.txt        |  56 ++++++++++
 Documentation/technical/api-trace2.txt | 141 ++++++++++++++-----------
 Documentation/trace2-target-values.txt |  10 ++
 4 files changed, 147 insertions(+), 62 deletions(-)
 create mode 100644 Documentation/config/trace2.txt
 create mode 100644 Documentation/trace2-target-values.txt

diff --git a/Documentation/config.txt b/Documentation/config.txt
index d87846faa6..7e2a6f61f5 100644
--- a/Documentation/config.txt
+++ b/Documentation/config.txt
@@ -422,6 +422,8 @@ include::config/submodule.txt[]
 
 include::config/tag.txt[]
 
+include::config/trace2.txt[]
+
 include::config/transfer.txt[]
 
 include::config/uploadarchive.txt[]
diff --git a/Documentation/config/trace2.txt b/Documentation/config/trace2.txt
new file mode 100644
index 0000000000..a5f409c1c1
--- /dev/null
+++ b/Documentation/config/trace2.txt
@@ -0,0 +1,56 @@
+Trace2 config settings are only read from the system and global
+config files; repository local and worktree config files and `-c`
+command line arguments are not respected.
+
+trace2.normalTarget::
+	This variable controls the normal target destination.
+	It may be overridden by the `GIT_TR2` environment variable.
+	The following table shows possible values.
+
+trace2.perfTarget::
+	This variable controls the performance target destination.
+	It may be overridden by the `GIT_TR2_PERF` environment variable.
+	The following table shows possible values.
+
+trace2.eventTarget::
+	This variable controls the event target destination.
+	It may be overridden by the `GIT_TR2_EVENT` environment variable.
+	The following table shows possible values.
++
+include::../trace2-target-values.txt[]
+
+trace2.normalBrief::
+	Boolean.  When true `time`, `filename`, and `line` fields are
+	omitted from normal output.  May be overridden by the
+	`GIT_TR2_BRIEF` environment variable.  Defaults to false.
+
+trace2.perfBrief::
+	Boolean.  When true `time`, `filename`, and `line` fields are
+	omitted from PERF output.  May be overridden by the
+	`GIT_TR2_PERF_BRIEF` environment variable.  Defaults to false.
+
+trace2.eventBrief::
+	Boolean.  When true `time`, `filename`, and `line` fields are
+	omitted from event output.  May be overridden by the
+	`GIT_TR2_EVENT_BRIEF` environment variable.  Defaults to false.
+
+trace2.eventNesting::
+	Integer.  Specifies desired depth of nested regions in the
+	event output.  Regions deeper than this value will be
+	omitted.  May be overridden by the `GIT_TR2_EVENT_NESTING`
+	environment variable.  Defaults to 2.
+
+trace2.configParams::
+	A comma-separated list of patterns of "important" config
+	settings that should be recorded in the trace2 output.
+	For example, `core.*,remote.*.url` would cause the trace2
+	output to contain events listing each configured remote.
+	May be overridden by the `GIT_TR2_CONFIG_PARAMS` environment
+	variable.  Unset by default.
+
+trace2.destinationDebug::
+	Boolean.  When true Git will print error messages when a
+	trace target destination cannot be opened for writing.
+	By default, these errors are suppressed and tracing is
+	silently disabled.  May be overridden by the
+	`GIT_TR2_DST_DEBUG` environment variable.
diff --git a/Documentation/technical/api-trace2.txt b/Documentation/technical/api-trace2.txt
index 43adbf00eb..e8eee25226 100644
--- a/Documentation/technical/api-trace2.txt
+++ b/Documentation/technical/api-trace2.txt
@@ -22,21 +22,41 @@ Targets are defined using a VTable allowing easy extension to other
 formats in the future.  This might be used to define a binary format,
 for example.
 
+Trace2 is controlled using `trace2.*` config values in the system and
+global config files and `GIT_TR2*` environment variables.  Trace2 does
+not read from repo local or worktree config files or respect `-c`
+command line config settings.
+
 == Trace2 Targets
 
 Trace2 defines the following set of Trace2 Targets.
 Format details are given in a later section.
 
-`GIT_TR2` (NORMAL)::
+=== The Normal Format Target
+
+The normal format target is a tradition printf format and similar
+to GIT_TRACE format.  This format is enabled with the `GIT_TR`
+environment variable or the `trace2.normalTarget` system or global
+config setting.
+
+For example
 
-	a simple printf format like GIT_TRACE.
-+
 ------------
 $ export GIT_TR2=~/log.normal
 $ git version
 git version 2.20.1.155.g426c96fcdb
 ------------
-+
+
+or
+
+------------
+$ git config --global trace2.normalTarget ~/log.normal
+$ git version
+git version 2.20.1.155.g426c96fcdb
+------------
+
+yields
+
 ------------
 $ cat ~/log.normal
 12:28:42.620009 common-main.c:38                  version 2.20.1.155.g426c96fcdb
@@ -46,17 +66,32 @@ $ cat ~/log.normal
 12:28:42.621250 trace2/tr2_tgt_normal.c:124       atexit elapsed:0.001265 code:0
 ------------
 
-`GIT_TR2_PERF` (PERF)::
+=== The Performance Format Target
+
+The performance format target (PERF) is a column-based format to
+replace GIT_TRACE_PERFORMANCE and is suitable for development and
+testing, possibly to complement tools like gprof.  This format is
+enabled with the `GIT_TR2_PERF` environment variable or the
+`trace2.perfTarget` system or global config setting.
+
+For example
 
-	a column-based format to replace GIT_TRACE_PERFORMANCE suitable for
-	development and testing, possibly to complement tools like gprof.
-+
 ------------
 $ export GIT_TR2_PERF=~/log.perf
 $ git version
 git version 2.20.1.155.g426c96fcdb
 ------------
-+
+
+or
+
+------------
+$ git config --global trace2.perfTarget ~/log.perf
+$ git version
+git version 2.20.1.155.g426c96fcdb
+------------
+
+yields
+
 ------------
 $ cat ~/log.perf
 12:28:42.620675 common-main.c:38                  | d0 | main                     | version      |     |           |           |            | 2.20.1.155.g426c96fcdb
@@ -66,16 +101,31 @@ $ cat ~/log.perf
 12:28:42.621259 trace2/tr2_tgt_perf.c:211         | d0 | main                     | atexit       |     |  0.001265 |           |            | code:0
 ------------
 
-`GIT_TR2_EVENT` (EVENT)::
+=== The Event Format Target
+
+The event format target is a JSON-based format of event data suitable
+for telemetry analysis.  This format is enabled with the `GIT_TR2_EVENT`
+environment variable or the `trace2.eventTarget` system or global config
+setting.
+
+For example
 
-	a JSON-based format of event data suitable for telemetry analysis.
-+
 ------------
 $ export GIT_TR2_EVENT=~/log.event
 $ git version
 git version 2.20.1.155.g426c96fcdb
 ------------
-+
+
+or
+
+------------
+$ git config --global trace2.eventTarget ~/log.event
+$ git version
+git version 2.20.1.155.g426c96fcdb
+------------
+
+yields
+
 ------------
 $ cat ~/log.event
 {"event":"version","sid":"sid":"20190408T191610.507018Z-H9b68c35f-P028492","thread":"main","time":"2019-01-16T17:28:42.620713Z","file":"common-main.c","line":38,"evt":"1","exe":"2.20.1.155.g426c96fcdb"}
@@ -85,37 +135,12 @@ $ cat ~/log.event
 {"event":"atexit","sid":"20190408T191610.507018Z-H9b68c35f-P028492","thread":"main","time":"2019-01-16T17:28:42.621268Z","file":"trace2/tr2_tgt_event.c","line":163,"t_abs":0.001265,"code":0}
 ------------
 
-== Enabling a Target
-
-A Trace2 Target is enabled when the corresponding environment variable
-(`GIT_TR2`, `GIT_TR2_PERF`, or `GIT_TR2_EVENT`) is set.  The following
-values are recognized.
+=== Enabling a Target
 
-`0`::
-`false`::
+To enable a target, set the corresponding environment variable or
+system or global config value to one of the following:
 
-	Disables the target.
-
-`1`::
-`true`::
-
-	Enables the target and writes stream to `STDERR`.
-
-`[2-9]`::
-
-	Enables the target and writes to the already opened file descriptor.
-
-`<absolute-pathname>`::
-
-	Enables the target, opens and writes to the file in append mode.
-
-`af_unix:[<socket_type>:]<absolute-pathname>`::
-
-	Enables the target, opens and writes to a Unix Domain Socket
-	(on platforms that support them).
-+
-Socket type can be either `stream` or `dgram`.  If the socket type is
-omitted, Git will try both.
+include::../trace2-target-values.txt[]
 
 == Trace2 API
 
@@ -243,15 +268,16 @@ significantly affects program performance or behavior, such as
 	Emits a "def_param" messages for "important" configuration
 	settings.
 +
-The environment variable `GIT_TR2_CONFIG_PARAMS` can be set to a
+The environment variable `GIT_TR2_CONFIG_PARAMS` or the `trace2.configParams`
+config value can be set to a
 list of patterns of important configuration settings, for example:
 `core.*,remote.*.url`.  This function will iterate over all config
 settings and emit a "def_param" message for each match.
 
 `void trace2_cmd_set_config(const char *key, const char *value)`::
 
-	Emits a "def_param" message for a specific configuration
-	setting IFF it matches the `GIT_TR2_CONFIG_PARAMS` pattern.
+	Emits a "def_param" message for a new or updated key/value
+	pair IF `key` is considered important.
 +
 This is used to hook into `git_config_set()` and catch any
 configuration changes and update a value previously reported by
@@ -418,9 +444,6 @@ recursive tree walk.
 
 === NORMAL Format
 
-NORMAL format is enabled when the `GIT_TR2` environment variable is
-set.
-
 Events are written as lines of the form:
 
 ------------
@@ -437,8 +460,8 @@ Events are written as lines of the form:
 Note that this may contain embedded LF or CRLF characters that are
 not escaped, so the event may spill across multiple lines.
 
-If `GIT_TR2_BRIEF` is true, the `time`, `filename`, and `line` fields
-are omitted.
+If `GIT_TR2_BRIEF` or `trace2.normalBrief` is true, the `time`, `filename`,
+and `line` fields are omitted.
 
 This target is intended to be more of a summary (like GIT_TRACE) and
 less detailed than the other targets.  It ignores thread, region, and
@@ -446,9 +469,6 @@ data messages, for example.
 
 === PERF Format
 
-PERF format is enabled when the `GIT_TR2_PERF` environment variable
-is set.
-
 Events are written as lines of the form:
 
 ------------
@@ -508,8 +528,8 @@ This field is in anticipation of in-proc submodules in the future.
 15:33:33.532712 wt-status.c:2331                  | d0 | main                     | region_leave | r1  |  0.127568 |  0.001504 | status     | label:print
 ------------
 
-If `GIT_TR2_PERF_BRIEF` is true, the `time`, `file`, and `line`
-fields are omitted.
+If `GIT_TR2_PERF_BRIEF` or `trace2.perfBrief` is true, the `time`, `file`,
+and `line` fields are omitted.
 
 ------------
 d0 | main                     | region_leave | r1  |  0.011717 |  0.009122 | index      | label:preload
@@ -520,9 +540,6 @@ during development and is quite noisy.
 
 === EVENT Format
 
-EVENT format is enabled when the `GIT_TR2_EVENT` environment
-variable is set.
-
 Each event is a JSON-object containing multiple key/value pairs
 written as a single line and followed by a LF.
 
@@ -576,9 +593,9 @@ The following key/value pairs are common to all events:
 `"repo":<repo-id>`::
 	when present, is the integer repo-id as described previously.
 
-If `GIT_TR2_EVENT_BRIEF` is true, the `file` and `line` fields are omitted
-from all events and the `time` field is only present on the "start" and
-"atexit" events.
+If `GIT_TR2_EVENT_BRIEF` or `trace2.eventBrief` is true, the `file`
+and `line` fields are omitted from all events and the `time` field is
+only present on the "start" and "atexit" events.
 
 ==== Event-Specific Key/Value Pairs
 
@@ -889,7 +906,7 @@ visited.
 The `category` field may be used in a future enhancement to
 do category-based filtering.
 +
-The `GIT_TR2_EVENT_NESTING` environment variable can be used to
+`GIT_TR2_EVENT_NESTING` or `trace2.eventNesting` can be used to
 filter deeply nested regions and data events.  It defaults to "2".
 
 `"region_leave"`::
diff --git a/Documentation/trace2-target-values.txt b/Documentation/trace2-target-values.txt
new file mode 100644
index 0000000000..27d3c64e66
--- /dev/null
+++ b/Documentation/trace2-target-values.txt
@@ -0,0 +1,10 @@
+--
+* `0` or `false` - Disables the target.
+* `1` or `true` - Writes to `STDERR`.
+* `[2-9]` - Writes to the already opened file descriptor.
+* `<absolute-pathname>` - Writes to the file in append mode.
+* `af_unix:[<socket_type>:]<absolute-pathname>` - Write to a
+Unix DomainSocket (on platforms that support them).  Socket
+type can be either `stream` or `dgram`; if omitted Git will
+try both.
+--
-- 
gitgitgadget

^ permalink raw reply	[flat|nested] 68+ messages in thread

* [PATCH v3 09/10] trace2: make SIDs more unique
  2019-04-11 15:18   ` [PATCH v3 00/10] " Jeff Hostetler via GitGitGadget
                       ` (8 preceding siblings ...)
  2019-04-11 15:18     ` [PATCH v3 10/10] trace2: update docs to describe system/global config settings Jeff Hostetler via GitGitGadget
@ 2019-04-11 15:18     ` Jeff Hostetler via GitGitGadget
  2019-04-12  2:29     ` [PATCH v3 00/10] trace2: load trace2 settings from system config Junio C Hamano
  2019-04-15 20:39     ` [PATCH v4 " Jeff Hostetler via GitGitGadget
  11 siblings, 0 replies; 68+ messages in thread
From: Jeff Hostetler via GitGitGadget @ 2019-04-11 15:18 UTC (permalink / raw)
  To: git
  Cc: gitster, peff, jrnieder, steadmon, avarab, Junio C Hamano,
	Jeff Hostetler

From: Jeff Hostetler <jeffhost@microsoft.com>

Update SID component construction to use the current UTC datetime
and a portion of the SHA1 of the hostname.

Use an simplified date/time format to make it easier to use the
SID component as a logfile filename.

Signed-off-by: Jeff Hostetler <jeffhost@microsoft.com>
---
 Documentation/technical/api-trace2.txt | 16 ++++----
 trace2/tr2_sid.c                       | 55 ++++++++++++++++++++++++--
 trace2/tr2_tbuf.c                      | 16 ++++++++
 trace2/tr2_tbuf.h                      |  1 +
 4 files changed, 76 insertions(+), 12 deletions(-)

diff --git a/Documentation/technical/api-trace2.txt b/Documentation/technical/api-trace2.txt
index cdc00bcc5d..43adbf00eb 100644
--- a/Documentation/technical/api-trace2.txt
+++ b/Documentation/technical/api-trace2.txt
@@ -78,11 +78,11 @@ git version 2.20.1.155.g426c96fcdb
 +
 ------------
 $ cat ~/log.event
-{"event":"version","sid":"1547659722619736-11614","thread":"main","time":"2019-01-16T17:28:42.620713Z","file":"common-main.c","line":38,"evt":"1","exe":"2.20.1.155.g426c96fcdb"}
-{"event":"start","sid":"1547659722619736-11614","thread":"main","time":"2019-01-16T17:28:42.621027Z","file":"common-main.c","line":39,"t_abs":0.001173,"argv":["git","version"]}
-{"event":"cmd_name","sid":"1547659722619736-11614","thread":"main","time":"2019-01-16T17:28:42.621122Z","file":"git.c","line":432,"name":"version","hierarchy":"version"}
-{"event":"exit","sid":"1547659722619736-11614","thread":"main","time":"2019-01-16T17:28:42.621236Z","file":"git.c","line":662,"t_abs":0.001227,"code":0}
-{"event":"atexit","sid":"1547659722619736-11614","thread":"main","time":"2019-01-16T17:28:42.621268Z","file":"trace2/tr2_tgt_event.c","line":163,"t_abs":0.001265,"code":0}
+{"event":"version","sid":"sid":"20190408T191610.507018Z-H9b68c35f-P028492","thread":"main","time":"2019-01-16T17:28:42.620713Z","file":"common-main.c","line":38,"evt":"1","exe":"2.20.1.155.g426c96fcdb"}
+{"event":"start","sid":"20190408T191610.507018Z-H9b68c35f-P028492","thread":"main","time":"2019-01-16T17:28:42.621027Z","file":"common-main.c","line":39,"t_abs":0.001173,"argv":["git","version"]}
+{"event":"cmd_name","sid":"20190408T191610.507018Z-H9b68c35f-P028492","thread":"main","time":"2019-01-16T17:28:42.621122Z","file":"git.c","line":432,"name":"version","hierarchy":"version"}
+{"event":"exit","sid":"20190408T191610.507018Z-H9b68c35f-P028492","thread":"main","time":"2019-01-16T17:28:42.621236Z","file":"git.c","line":662,"t_abs":0.001227,"code":0}
+{"event":"atexit","sid":"20190408T191610.507018Z-H9b68c35f-P028492","thread":"main","time":"2019-01-16T17:28:42.621268Z","file":"trace2/tr2_tgt_event.c","line":163,"t_abs":0.001265,"code":0}
 ------------
 
 == Enabling a Target
@@ -540,11 +540,11 @@ The following key/value pairs are common to all events:
 ------------
 {
 	"event":"version",
-	"sid":"1547659722619736-11614",
+	"sid":"20190408T191827.272759Z-H9b68c35f-P011764",
 	"thread":"main",
-	"time":"2019-01-16T17:28:42.620713Z",
+	"time":"2019-04-08T19:18:27.282761Z",
 	"file":"common-main.c",
-	"line":38,
+	"line":42,
 	...
 }
 ------------
diff --git a/trace2/tr2_sid.c b/trace2/tr2_sid.c
index 984524a43c..68d723bc6c 100644
--- a/trace2/tr2_sid.c
+++ b/trace2/tr2_sid.c
@@ -1,4 +1,5 @@
 #include "cache.h"
+#include "trace2/tr2_tbuf.h"
 #include "trace2/tr2_sid.h"
 
 #define TR2_ENVVAR_PARENT_SID "GIT_TR2_PARENT_SID"
@@ -6,6 +7,55 @@
 static struct strbuf tr2sid_buf = STRBUF_INIT;
 static int tr2sid_nr_git_parents;
 
+/*
+ * Compute the final component of the SID representing the current process.
+ * This should uniquely identify the process and be a valid filename (to
+ * allow writing trace2 data to per-process files).  It should also be fixed
+ * possible length for use as a database key.
+ *
+ * "<yyyymmdd>T<hhmmss>.<fraction>Z-<host>-<process>"
+ *
+ * where <host> is a 9 character string:
+ *    "H<first_8_chars_of_sha1_of_hostname>"
+ *    "Localhost" when no hostname.
+ *
+ * where <process> is a possibly wrapped PID:
+ *    "P<6-digit-pid>"
+ *    "W<wrapped-6-digit-pid>" when PID too big.
+ *    
+ */
+static void tr2_sid_append_my_sid_component(void)
+{
+	const struct git_hash_algo *algo = &hash_algos[GIT_HASH_SHA1];
+	struct tr2_tbuf tb_now;
+	git_hash_ctx ctx;
+	uintmax_t pid = getpid();
+	unsigned char hash[GIT_MAX_RAWSZ + 1];
+	char hex[GIT_MAX_HEXSZ + 1];
+	char hostname[HOST_NAME_MAX + 1];
+
+	tr2_tbuf_utc_datetime(&tb_now);
+	strbuf_addstr(&tr2sid_buf, tb_now.buf);
+
+	strbuf_addch(&tr2sid_buf, '-');
+	if (xgethostname(hostname, sizeof(hostname)))
+		strbuf_add(&tr2sid_buf, "Localhost", 9);
+	else {
+		algo->init_fn(&ctx);
+		algo->update_fn(&ctx, hostname, strlen(hostname));
+		algo->final_fn(hash, &ctx);
+		hash_to_hex_algop_r(hex, hash, algo);
+		strbuf_addch(&tr2sid_buf, 'H');
+		strbuf_add(&tr2sid_buf, hex, 8);
+	}
+
+	strbuf_addch(&tr2sid_buf, '-');
+	if (pid > 999999)
+		strbuf_addf(&tr2sid_buf, "W%06d", (int)(pid % 1000000));
+	else
+		strbuf_addf(&tr2sid_buf, "P%06d", (int)pid);
+}
+
 /*
  * Compute a "unique" session id (SID) for the current process.  This allows
  * all events from this process to have a single label (much like a PID).
@@ -20,7 +70,6 @@ static int tr2sid_nr_git_parents;
  */
 static void tr2_sid_compute(void)
 {
-	uint64_t us_now;
 	const char *parent_sid;
 
 	if (tr2sid_buf.len)
@@ -38,9 +87,7 @@ static void tr2_sid_compute(void)
 		tr2sid_nr_git_parents++;
 	}
 
-	us_now = getnanotime() / 1000;
-	strbuf_addf(&tr2sid_buf, "%" PRIuMAX "-%" PRIdMAX, (uintmax_t)us_now,
-		    (intmax_t)getpid());
+	tr2_sid_append_my_sid_component();
 
 	setenv(TR2_ENVVAR_PARENT_SID, tr2sid_buf.buf, 1);
 }
diff --git a/trace2/tr2_tbuf.c b/trace2/tr2_tbuf.c
index eb1b240d8a..c8a19ac341 100644
--- a/trace2/tr2_tbuf.c
+++ b/trace2/tr2_tbuf.c
@@ -30,3 +30,19 @@ void tr2_tbuf_utc_datetime_extended(struct tr2_tbuf *tb)
 		  tm.tm_mon + 1, tm.tm_mday, tm.tm_hour, tm.tm_min, tm.tm_sec,
 		  (long)tv.tv_usec);
 }
+
+void tr2_tbuf_utc_datetime(struct tr2_tbuf *tb)
+{
+	struct timeval tv;
+	struct tm tm;
+	time_t secs;
+
+	gettimeofday(&tv, NULL);
+	secs = tv.tv_sec;
+	gmtime_r(&secs, &tm);
+
+	xsnprintf(tb->buf, sizeof(tb->buf),
+		  "%4d%02d%02dT%02d%02d%02d.%06ldZ", tm.tm_year + 1900,
+		  tm.tm_mon + 1, tm.tm_mday, tm.tm_hour, tm.tm_min, tm.tm_sec,
+		  (long)tv.tv_usec);
+}
diff --git a/trace2/tr2_tbuf.h b/trace2/tr2_tbuf.h
index 2a1d173ff2..fa853d8f42 100644
--- a/trace2/tr2_tbuf.h
+++ b/trace2/tr2_tbuf.h
@@ -19,5 +19,6 @@ void tr2_tbuf_local_time(struct tr2_tbuf *tb);
  * Fill buffer with formatted UTC datatime string.
  */
 void tr2_tbuf_utc_datetime_extended(struct tr2_tbuf *tb);
+void tr2_tbuf_utc_datetime(struct tr2_tbuf *tb);
 
 #endif /* TR2_TBUF_H */
-- 
gitgitgadget


^ permalink raw reply	[flat|nested] 68+ messages in thread

* Re: [PATCH v3 00/10] trace2: load trace2 settings from system config
  2019-04-11 15:18   ` [PATCH v3 00/10] " Jeff Hostetler via GitGitGadget
                       ` (9 preceding siblings ...)
  2019-04-11 15:18     ` [PATCH v3 09/10] trace2: make SIDs more unique Jeff Hostetler via GitGitGadget
@ 2019-04-12  2:29     ` Junio C Hamano
  2019-04-12 13:47       ` Jeff Hostetler
  2019-04-15 20:39     ` [PATCH v4 " Jeff Hostetler via GitGitGadget
  11 siblings, 1 reply; 68+ messages in thread
From: Junio C Hamano @ 2019-04-12  2:29 UTC (permalink / raw)
  To: Jeff Hostetler via GitGitGadget; +Cc: git, peff, jrnieder, steadmon, avarab

"Jeff Hostetler via GitGitGadget" <gitgitgadget@gmail.com> writes:

> Here is version 3.
> [] It incorporates Ævar's suggestions WRT the format and uniqueness of the
> SID. [] It now reads both system and global config for trace2 settings and
> handles includes as Jonathan suggested.

Following the ISO more closely with Ts and Zs in the format looks
like a good idea (i.e. it gives a more familiar-looking result).  I
have no string opinions on the per-user config or inclusion, but I
think it probably is an essential ingredient to give an opt-out
escape hatch to make this appear less big-brotherly [*1*].

	Side note *1*: and hence less scary.  An otherwise useful
	mechanism can have an appearance that it can also be misused
	for bad purposes, and at that point, to those with fear, it
	does not matter how useful an application the mechanism has.

	I think "by default you are opting in due to your belonging
	to this organization in the first place (hence we give you
	/etc/gitconfig that lets us collect your usage patterns) but
	you could easily opt-out by overriding in $HOME/.gitconfig"
	strikes a good balance.

> I added a read_very_early_config() function that is similar to 
> read_early_config()but omits repo local, worktree, and -c command line
> settings. This felt like a little bit of a hack, but it made the intent
> clear.

I am not yet judging if the "very early config" itself is a good
thing to have (and if it is good, then it is not a "hack" ;-)), but
I very much agree that it is a very good change to have a helper
that makes the intent clear.

>      -+# Now test using system config by using a mocked up config file
>      -+# rather than inheriting "/etc/gitconfig".  Here we do not use
>      -+# GIT_TR2* environment variables.
>      -+
>       +unset GIT_TR2_BRIEF


This does not have to be sane_unset, as we are not aiming for making
our tests "set -e" clean.  But in tXXXX-*.sh scripts, it may not be
a bad idea to stick to sane_unset regardless, as people tend to cut
and paste without thinking enough.

>      @@ -512,19 +454,28 @@
>       + */
>       +/* clang-format off */
>
>      ++	[TR2_SYSENV_CFG_PARAM]     = { "GIT_TR2_CONFIG_PARAMS",
>      ++				       "trace2.configparams" },
>      ++
>      ++	[TR2_SYSENV_DST_DEBUG]     = { "GIT_TR2_DST_DEBUG",
>      ++				       "trace2.destinationdebug" },
>      ++
>      ++	[TR2_SYSENV_NORMAL]        = { "GIT_TR2",
>      ++				       "trace2.normaltarget" },
>      ++	[TR2_SYSENV_NORMAL_BRIEF]  = { "GIT_TR2_BRIEF",
>      ++				       "trace2.normalbrief" },
>      ++
>      ++	[TR2_SYSENV_EVENT]         = { "GIT_TR2_EVENT",
>      ++				       "trace2.eventtarget" },
>      ++	[TR2_SYSENV_EVENT_BRIEF]   = { "GIT_TR2_EVENT_BRIEF",
>      ++				       "trace2.eventbrief" },
>      ++	[TR2_SYSENV_EVENT_NESTING] = { "GIT_TR2_EVENT_NESTING",
>      ++				       "trace2.eventnesting" },
>      ++
>      ++	[TR2_SYSENV_PERF]          = { "GIT_TR2_PERF",
>      ++				       "trace2.perftarget" },
>      ++	[TR2_SYSENV_PERF_BRIEF]    = { "GIT_TR2_PERF_BRIEF",
>      ++				       "trace2.perfbrief" },


With use of designated initializers, the table got a lot cleaner to
read.  Is the above "format off" still needed (I am a bit curious
how clang-format wants these entries to look like)?

>      ++	if (pid > 999999)
>      ++		strbuf_addf(&tr2sid_buf, "W%06d", (int)(pid % 1000000));
>      ++	else
>      ++		strbuf_addf(&tr2sid_buf, "P%06d", (int)pid);

I do not think it matters too much, but this is kind-of curious.

How would the users of the log utilize the distinction between W and
P?  Do they discard the ones with W when they care about the exact
process that left the trace entries, or something?  If it's not a
plausibly useful use pattern (and I do not think it is), I wonder if
we want to go with only W (i.e. truncated to the lower N digits)
entries, if you are shooting for a fixed-width output from this
function.  If you want less chance of collisions, you obviously
could use hexadecimal to gain back a few more bits.

After all, if the application does care the PID, that could be in
the log data itself (i.e. an "start" event can say "my pid is blah").

Thanks.  I'll wait until learning what others think.

^ permalink raw reply	[flat|nested] 68+ messages in thread

* Re: [PATCH v3 01/10] config: initialize opts structure in repo_read_config()
  2019-04-11 15:18     ` [PATCH v3 01/10] config: initialize opts structure in repo_read_config() Jeff Hostetler via GitGitGadget
@ 2019-04-12  3:52       ` Jonathan Nieder
  2019-04-15 14:34         ` Johannes Schindelin
  0 siblings, 1 reply; 68+ messages in thread
From: Jonathan Nieder @ 2019-04-12  3:52 UTC (permalink / raw)
  To: Jeff Hostetler via GitGitGadget
  Cc: git, gitster, peff, steadmon, avarab, Jeff Hostetler

Hi,

Jeff Hostetler wrote:

> Initialize opts structure in repo_read_config().

Good find.  I wonder if there are some flags we can turn on with
DEVELOPER=1 to prevent this kind of issue going undetected in the
future (or maybe this means we need to get the valgrind or ASan
testing modes to be fast enough for people to consistently run them).

[...]
>  config.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)

Reviewed-by: Jonathan Nieder <jrnieder@gmail.com>

Thanks.

^ permalink raw reply	[flat|nested] 68+ messages in thread

* Re: [PATCH v3 00/10] trace2: load trace2 settings from system config
  2019-04-12  2:29     ` [PATCH v3 00/10] trace2: load trace2 settings from system config Junio C Hamano
@ 2019-04-12 13:47       ` Jeff Hostetler
  0 siblings, 0 replies; 68+ messages in thread
From: Jeff Hostetler @ 2019-04-12 13:47 UTC (permalink / raw)
  To: Junio C Hamano, Jeff Hostetler via GitGitGadget
  Cc: git, peff, jrnieder, steadmon, avarab



On 4/11/2019 10:29 PM, Junio C Hamano wrote:
> "Jeff Hostetler via GitGitGadget" <gitgitgadget@gmail.com> writes:
> 
[...]
>>       @@ -512,19 +454,28 @@
>>        + */
>>        +/* clang-format off */
>>
>>       ++	[TR2_SYSENV_CFG_PARAM]     = { "GIT_TR2_CONFIG_PARAMS",
>>       ++				       "trace2.configparams" },
>>       ++
>>       ++	[TR2_SYSENV_DST_DEBUG]     = { "GIT_TR2_DST_DEBUG",
>>       ++				       "trace2.destinationdebug" },
>>       ++
>>       ++	[TR2_SYSENV_NORMAL]        = { "GIT_TR2",
>>       ++				       "trace2.normaltarget" },
>>       ++	[TR2_SYSENV_NORMAL_BRIEF]  = { "GIT_TR2_BRIEF",
>>       ++				       "trace2.normalbrief" },
>>       ++
>>       ++	[TR2_SYSENV_EVENT]         = { "GIT_TR2_EVENT",
>>       ++				       "trace2.eventtarget" },
>>       ++	[TR2_SYSENV_EVENT_BRIEF]   = { "GIT_TR2_EVENT_BRIEF",
>>       ++				       "trace2.eventbrief" },
>>       ++	[TR2_SYSENV_EVENT_NESTING] = { "GIT_TR2_EVENT_NESTING",
>>       ++				       "trace2.eventnesting" },
>>       ++
>>       ++	[TR2_SYSENV_PERF]          = { "GIT_TR2_PERF",
>>       ++				       "trace2.perftarget" },
>>       ++	[TR2_SYSENV_PERF_BRIEF]    = { "GIT_TR2_PERF_BRIEF",
>>       ++				       "trace2.perfbrief" },
> 
> 
> With use of designated initializers, the table got a lot cleaner to
> read.  Is the above "format off" still needed (I am a bit curious
> how clang-format wants these entries to look like)?

clang-format suggests getting rid of the extra whitespace on the
lines, so we lose all of the column alignment.  Then it wants to
line-wrap some but not all of the lines.  So it is a bit of a mess
to look at.


> 
>>       ++	if (pid > 999999)
>>       ++		strbuf_addf(&tr2sid_buf, "W%06d", (int)(pid % 1000000));
>>       ++	else
>>       ++		strbuf_addf(&tr2sid_buf, "P%06d", (int)pid);
> 
> I do not think it matters too much, but this is kind-of curious.
> 
> How would the users of the log utilize the distinction between W and
> P?  Do they discard the ones with W when they care about the exact
> process that left the trace entries, or something?  If it's not a
> plausibly useful use pattern (and I do not think it is), I wonder if
> we want to go with only W (i.e. truncated to the lower N digits)
> entries, if you are shooting for a fixed-width output from this
> function.  If you want less chance of collisions, you obviously
> could use hexadecimal to gain back a few more bits.
> 
> After all, if the application does care the PID, that could be in
> the log data itself (i.e. an "start" event can say "my pid is blah").

Right. Ævar suggested adding the full or wrapped PID so that the SID
would be a fixed length.  I stuck with decimal rather than hex because
it's easier to match up a running command with '/usr/bin/ps' output,
but that's no big deal either way.  It might be simpler to just %08lx
it and be done with it.

Jeff


^ permalink raw reply	[flat|nested] 68+ messages in thread

* Re: [PATCH v3 01/10] config: initialize opts structure in repo_read_config()
  2019-04-12  3:52       ` Jonathan Nieder
@ 2019-04-15 14:34         ` Johannes Schindelin
  0 siblings, 0 replies; 68+ messages in thread
From: Johannes Schindelin @ 2019-04-15 14:34 UTC (permalink / raw)
  To: Jonathan Nieder
  Cc: Jeff Hostetler via GitGitGadget, git, gitster, peff, steadmon,
	avarab, Jeff Hostetler

Hi Jonathan,

On Thu, 11 Apr 2019, Jonathan Nieder wrote:

> Jeff Hostetler wrote:
>
> > Initialize opts structure in repo_read_config().
>
> Good find.

Heh, it really was our CI that found it, and it was I (with valgrind's
help) who identified the problem and proposed the fix. So: thank you!

> I wonder if there are some flags we can turn on with
> DEVELOPER=1 to prevent this kind of issue going undetected in the
> future (or maybe this means we need to get the valgrind or ASan
> testing modes to be fast enough for people to consistently run them).

Sadly, I do not think that either is an option. Such uninitialized memory
is really hard to catch without in-depth analysis, so DEVELOPER=1 is out.
And `valgrind` (or the faster alternative, DrMemory) have to spend quite a
bit of time to do what they do, and it is unlikely that that could ever be
made faster.

A better approach might be static analysis (and I do not mean the diet
coke of static analysis that we run as part of our CI, but something as
powerful as Coverity).

Sadly, Coverity makes it super hard to switch off false positives
regarding e.g. our use of FLEX_ARRAY or strbuf's strbuf_slopbuf.

For quite a while, I wanted to play with [infer](https://fbinfer.com/), in
the hopes that it would be possible to do customize what cannot be
customized with Coverity. Alas, their use of OCaml (why do they make it so
hard?) puts quite the bit of a road block ahead of me in that endeavor.

Ciao,
Dscho

^ permalink raw reply	[flat|nested] 68+ messages in thread

* [PATCH v4 00/10] trace2: load trace2 settings from system config
  2019-04-11 15:18   ` [PATCH v3 00/10] " Jeff Hostetler via GitGitGadget
                       ` (10 preceding siblings ...)
  2019-04-12  2:29     ` [PATCH v3 00/10] trace2: load trace2 settings from system config Junio C Hamano
@ 2019-04-15 20:39     ` " Jeff Hostetler via GitGitGadget
  2019-04-15 20:39       ` [PATCH v4 01/10] config: initialize opts structure in repo_read_config() Jeff Hostetler via GitGitGadget
                         ` (10 more replies)
  11 siblings, 11 replies; 68+ messages in thread
From: Jeff Hostetler via GitGitGadget @ 2019-04-15 20:39 UTC (permalink / raw)
  To: git; +Cc: gitster, peff, jrnieder, steadmon, avarab, Junio C Hamano

Version 4 fixes a few clang-format warnings and simplifies the PID field in
the SID.

Jeff Hostetler (10):
  config: initialize opts structure in repo_read_config()
  trace2: refactor setting process starting time
  trace2: add absolute elapsed time to start event
  trace2: find exec-dir before trace2 initialization
  config: add read_very_early_config()
  trace2: use system/global config for default trace2 settings
  trace2: report peak memory usage of the process
  trace2: clarify UTC datetime formatting
  trace2: make SIDs more unique
  trace2: update docs to describe system/global config settings

 Documentation/config.txt                 |   2 +
 Documentation/config/trace2.txt          |  56 ++++++++
 Documentation/technical/api-trace2.txt   | 176 +++++++++++++----------
 Documentation/trace2-target-values.txt   |  10 ++
 Makefile                                 |   1 +
 common-main.c                            |   8 +-
 compat/mingw.c                           |   2 +
 compat/win32/trace2_win32_process_info.c |  50 ++++++-
 config.c                                 |  25 +++-
 config.h                                 |   4 +
 t/t0210-trace2-normal.sh                 |  49 ++++++-
 t/t0211-trace2-perf.sh                   |  43 ++++--
 t/t0212-trace2-event.sh                  |  42 +++++-
 trace2.c                                 |  21 ++-
 trace2.h                                 |  43 ++++--
 trace2/tr2_cfg.c                         |   7 +-
 trace2/tr2_dst.c                         |  26 ++--
 trace2/tr2_dst.h                         |   3 +-
 trace2/tr2_sid.c                         |  53 ++++++-
 trace2/tr2_sysenv.c                      | 127 ++++++++++++++++
 trace2/tr2_sysenv.h                      |  36 +++++
 trace2/tr2_tbuf.c                        |  19 ++-
 trace2/tr2_tbuf.h                        |   5 +-
 trace2/tr2_tgt.h                         |   1 +
 trace2/tr2_tgt_event.c                   |  53 +++----
 trace2/tr2_tgt_normal.c                  |  19 +--
 trace2/tr2_tgt_perf.c                    |  23 +--
 trace2/tr2_tls.c                         |  38 +++--
 trace2/tr2_tls.h                         |   8 +-
 29 files changed, 747 insertions(+), 203 deletions(-)
 create mode 100644 Documentation/config/trace2.txt
 create mode 100644 Documentation/trace2-target-values.txt
 create mode 100644 trace2/tr2_sysenv.c
 create mode 100644 trace2/tr2_sysenv.h


base-commit: 041f5ea1cf987a4068ef5f39ba0a09be85952064
Published-As: https://github.com/gitgitgadget/git/releases/tag/pr-169%2Fjeffhostetler%2Fcore-tr2-startup-and-sysenv-v4
Fetch-It-Via: git fetch https://github.com/gitgitgadget/git pr-169/jeffhostetler/core-tr2-startup-and-sysenv-v4
Pull-Request: https://github.com/gitgitgadget/git/pull/169

Range-diff vs v3:

  1:  ea8c199f91 !  1:  f6653f1c59 config: initialize opts structure in repo_read_config()
     @@ -25,7 +25,7 @@
       static void repo_read_config(struct repository *repo)
       {
      -	struct config_options opts;
     -+	struct config_options opts = {0};
     ++	struct config_options opts = { 0 };
       
       	opts.respect_includes = 1;
       	opts.commondir = repo->commondir;
  2:  3dbcfc6a8d !  2:  48e34834b6 trace2: refactor setting process starting time
     @@ -196,8 +196,8 @@
      -	 * thread's array (because of reallocs).
      -	 */
      -	tr2tls_us_start_main = tr2tls_thread_main->array_us_start[0];
     -+	tr2tls_thread_main = tr2tls_create_self("main",
     -+						tr2tls_us_start_process);
     ++	tr2tls_thread_main =
     ++		tr2tls_create_self("main", tr2tls_us_start_process);
       }
       
       void tr2tls_release(void)
  3:  8b00025af5 =  3:  175371fb54 trace2: add absolute elapsed time to start event
  4:  c3c5f6a96b =  4:  94729b284c trace2: find exec-dir before trace2 initialization
  5:  d15be7b63a !  5:  b0fe1385f1 config: add read_very_early_config()
     @@ -16,8 +16,8 @@
       
       	current_parsing_scope = CONFIG_SCOPE_REPO;
      -	if (repo_config && !access_or_die(repo_config, R_OK, 0))
     -+	if (!opts->ignore_repo &&
     -+	    repo_config && !access_or_die(repo_config, R_OK, 0))
     ++	if (!opts->ignore_repo && repo_config &&
     ++	    !access_or_die(repo_config, R_OK, 0))
       		ret += git_config_from_file(fn, repo_config, data);
       
       	/*
     @@ -25,8 +25,7 @@
       	 * But let's not complicate things before it's actually needed.
       	 */
      -	if (repository_format_worktree_config) {
     -+	if (!opts->ignore_worktree &&
     -+	    repository_format_worktree_config) {
     ++	if (!opts->ignore_worktree && repository_format_worktree_config) {
       		char *path = git_pathdup("config.worktree");
       		if (!access_or_die(path, R_OK, 0))
       			ret += git_config_from_file(fn, path, data);
     @@ -35,8 +34,7 @@
       
       	current_parsing_scope = CONFIG_SCOPE_CMDLINE;
      -	if (git_config_from_parameters(fn, data) < 0)
     -+	if (!opts->ignore_cmdline &&
     -+	    git_config_from_parameters(fn, data) < 0)
     ++	if (!opts->ignore_cmdline && git_config_from_parameters(fn, data) < 0)
       		die(_("unable to parse command-line config"));
       
       	current_parsing_scope = CONFIG_SCOPE_UNKNOWN;
     @@ -50,7 +48,7 @@
      + */
      +void read_very_early_config(config_fn_t cb, void *data)
      +{
     -+	struct config_options opts = {0};
     ++	struct config_options opts = { 0 };
      +
      +	opts.respect_includes = 1;
      +	opts.ignore_repo = 1;
  6:  c085a482dd !  6:  550cad6189 trace2: use system/global config for default trace2 settings
     @@ -41,16 +41,17 @@
       --- a/t/t0210-trace2-normal.sh
       +++ b/t/t0210-trace2-normal.sh
      @@
     - #!/bin/sh
     - 
     -+# Turn off any inherited trace2 settings for this test.
     -+unset GIT_TR2 GIT_TR2_PERF GIT_TR2_EVENT
     -+unset GIT_TR2_BRIEF
     -+unset GIT_TR2_CONFIG_PARAMS
     -+
       test_description='test trace2 facility (normal target)'
       . ./test-lib.sh
       
     ++# Turn off any inherited trace2 settings for this test.
     ++sane_unset GIT_TR2 GIT_TR2_PERF GIT_TR2_EVENT
     ++sane_unset GIT_TR2_BRIEF
     ++sane_unset GIT_TR2_CONFIG_PARAMS
     ++
     + # Add t/helper directory to PATH so that we can use a relative
     + # path to run nested instances of test-tool.exe (see 004child).
     + # This helps with HEREDOC comparisons later.
      @@
       # Warning: So you may see extra lines in artifact files when
       # Warning: interactively debugging.
     @@ -67,7 +68,7 @@
       	test_cmp expect actual
       '
       
     -+unset GIT_TR2_BRIEF
     ++sane_unset GIT_TR2_BRIEF
      +
      +# Now test without environment variables and get all Trace2 settings
      +# from the global config.
     @@ -112,16 +113,17 @@
       --- a/t/t0211-trace2-perf.sh
       +++ b/t/t0211-trace2-perf.sh
      @@
     - #!/bin/sh
     - 
     -+# Turn off any inherited trace2 settings for this test.
     -+unset GIT_TR2 GIT_TR2_PERF GIT_TR2_EVENT
     -+unset GIT_TR2_PERF_BRIEF
     -+unset GIT_TR2_CONFIG_PARAMS
     -+
       test_description='test trace2 facility (perf target)'
       . ./test-lib.sh
       
     ++# Turn off any inherited trace2 settings for this test.
     ++sane_unset GIT_TR2 GIT_TR2_PERF GIT_TR2_EVENT
     ++sane_unset GIT_TR2_PERF_BRIEF
     ++sane_unset GIT_TR2_CONFIG_PARAMS
     ++
     + # Add t/helper directory to PATH so that we can use a relative
     + # path to run nested instances of test-tool.exe (see 004child).
     + # This helps with HEREDOC comparisons later.
      @@
       # Warning: So you may see extra lines in artifact files when
       # Warning: interactively debugging.
     @@ -138,7 +140,7 @@
       	test_cmp expect actual
       '
       
     -+unset GIT_TR2_PERF_BRIEF
     ++sane_unset GIT_TR2_PERF_BRIEF
      +
      +# Now test without environment variables and get all Trace2 settings
      +# from the global config.
     @@ -165,16 +167,17 @@
       --- a/t/t0212-trace2-event.sh
       +++ b/t/t0212-trace2-event.sh
      @@
     - #!/bin/sh
     + test_description='test trace2 facility'
     + . ./test-lib.sh
       
      +# Turn off any inherited trace2 settings for this test.
     -+unset GIT_TR2 GIT_TR2_PERF GIT_TR2_EVENT
     -+unset GIT_TR2_BARE
     -+unset GIT_TR2_CONFIG_PARAMS
     ++sane_unset GIT_TR2 GIT_TR2_PERF GIT_TR2_EVENT
     ++sane_unset GIT_TR2_BARE
     ++sane_unset GIT_TR2_CONFIG_PARAMS
      +
     - test_description='test trace2 facility'
     - . ./test-lib.sh
     + perl -MJSON::PP -e 0 >/dev/null 2>&1 && test_set_prereq JSON_PP
       
     + # Add t/helper directory to PATH so that we can use a relative
      @@
       # Warning: So you may see extra lines in artifact files when
       # Warning: interactively debugging.
     @@ -353,7 +356,8 @@
       		if (tr2_dst_want_warning())
       			warning("trace2: invalid AF_UNIX value '%s' for '%s' tracing",
      -				tgt_value, dst->env_var_name);
     -+				tgt_value, tr2_sysenv_display_name(dst->sysenv_var));
     ++				tgt_value,
     ++				tr2_sysenv_display_name(dst->sysenv_var));
       
       		tr2_dst_trace_disable(dst);
       		return 0;
     @@ -371,7 +375,8 @@
       	if (tr2_dst_want_warning())
       		warning("trace2: could not connect to socket '%s' for '%s' tracing: %s",
      -			path, dst->env_var_name, strerror(e));
     -+			path, tr2_sysenv_display_name(dst->sysenv_var), strerror(e));
     ++			path, tr2_sysenv_display_name(dst->sysenv_var),
     ++			strerror(e));
       
       	tr2_dst_trace_disable(dst);
       	return 0;
  7:  2a7a933875 !  7:  56d8ce3fd6 trace2: report peak memory usage of the process
     @@ -40,8 +40,8 @@
      + */
      +static void get_peak_memory_info(void)
      +{
     -+	DECLARE_PROC_ADDR(psapi.dll, BOOL, GetProcessMemoryInfo,
     -+			  HANDLE, PPROCESS_MEMORY_COUNTERS, DWORD);
     ++	DECLARE_PROC_ADDR(psapi.dll, BOOL, GetProcessMemoryInfo, HANDLE,
     ++			  PPROCESS_MEMORY_COUNTERS, DWORD);
      +
      +	if (INIT_PROC_ADDR(GetProcessMemoryInfo)) {
      +		PROCESS_MEMORY_COUNTERS pmc;
  8:  56f357dc7b =  8:  196a9d2c85 trace2: clarify UTC datetime formatting
  9:  156ffde489 !  9:  9fdcb50140 trace2: make SIDs more unique
     @@ -63,7 +63,7 @@
      + * Compute the final component of the SID representing the current process.
      + * This should uniquely identify the process and be a valid filename (to
      + * allow writing trace2 data to per-process files).  It should also be fixed
     -+ * possible length for use as a database key.
     ++ * length for possible use as a database key.
      + *
      + * "<yyyymmdd>T<hhmmss>.<fraction>Z-<host>-<process>"
      + *
     @@ -71,17 +71,19 @@
      + *    "H<first_8_chars_of_sha1_of_hostname>"
      + *    "Localhost" when no hostname.
      + *
     -+ * where <process> is a possibly wrapped PID:
     -+ *    "P<6-digit-pid>"
     -+ *    "W<wrapped-6-digit-pid>" when PID too big.
     -+ *    
     ++ * where <process> is a 9 character string containing the least signifcant
     ++ * 32 bits in the process-id.
     ++ *    "P<pid>"
     ++ * (This is an abribrary choice.  On most systems pid_t is a 32 bit value,
     ++ * so limit doesn't matter.  On larger systems, a truncated value is fine
     ++ * for our purposes here.)
      + */
      +static void tr2_sid_append_my_sid_component(void)
      +{
      +	const struct git_hash_algo *algo = &hash_algos[GIT_HASH_SHA1];
      +	struct tr2_tbuf tb_now;
      +	git_hash_ctx ctx;
     -+	uintmax_t pid = getpid();
     ++	pid_t pid = getpid();
      +	unsigned char hash[GIT_MAX_RAWSZ + 1];
      +	char hex[GIT_MAX_HEXSZ + 1];
      +	char hostname[HOST_NAME_MAX + 1];
     @@ -101,11 +103,7 @@
      +		strbuf_add(&tr2sid_buf, hex, 8);
      +	}
      +
     -+	strbuf_addch(&tr2sid_buf, '-');
     -+	if (pid > 999999)
     -+		strbuf_addf(&tr2sid_buf, "W%06d", (int)(pid % 1000000));
     -+	else
     -+		strbuf_addf(&tr2sid_buf, "P%06d", (int)pid);
     ++	strbuf_addf(&tr2sid_buf, "-P%08"PRIx32, (uint32_t)pid);
      +}
      +
       /*
     @@ -149,10 +147,9 @@
      +	secs = tv.tv_sec;
      +	gmtime_r(&secs, &tm);
      +
     -+	xsnprintf(tb->buf, sizeof(tb->buf),
     -+		  "%4d%02d%02dT%02d%02d%02d.%06ldZ", tm.tm_year + 1900,
     -+		  tm.tm_mon + 1, tm.tm_mday, tm.tm_hour, tm.tm_min, tm.tm_sec,
     -+		  (long)tv.tv_usec);
     ++	xsnprintf(tb->buf, sizeof(tb->buf), "%4d%02d%02dT%02d%02d%02d.%06ldZ",
     ++		  tm.tm_year + 1900, tm.tm_mon + 1, tm.tm_mday, tm.tm_hour,
     ++		  tm.tm_min, tm.tm_sec, (long)tv.tv_usec);
      +}
      
       diff --git a/trace2/tr2_tbuf.h b/trace2/tr2_tbuf.h
 10:  285beb2b2d ! 10:  3414016d04 trace2: update docs to describe system/global config settings
     @@ -188,53 +188,59 @@
       git version 2.20.1.155.g426c96fcdb
       ------------
      -+
     -+
     -+or
     -+
     -+------------
     -+$ git config --global trace2.eventTarget ~/log.event
     -+$ git version
     -+git version 2.20.1.155.g426c96fcdb
     -+------------
     -+
     -+yields
     -+
     - ------------
     - $ cat ~/log.event
     - {"event":"version","sid":"sid":"20190408T191610.507018Z-H9b68c35f-P028492","thread":"main","time":"2019-01-16T17:28:42.620713Z","file":"common-main.c","line":38,"evt":"1","exe":"2.20.1.155.g426c96fcdb"}
     -@@
     - {"event":"atexit","sid":"20190408T191610.507018Z-H9b68c35f-P028492","thread":"main","time":"2019-01-16T17:28:42.621268Z","file":"trace2/tr2_tgt_event.c","line":163,"t_abs":0.001265,"code":0}
     - ------------
     - 
     +-------------
     +-$ cat ~/log.event
     +-{"event":"version","sid":"sid":"20190408T191610.507018Z-H9b68c35f-P028492","thread":"main","time":"2019-01-16T17:28:42.620713Z","file":"common-main.c","line":38,"evt":"1","exe":"2.20.1.155.g426c96fcdb"}
     +-{"event":"start","sid":"20190408T191610.507018Z-H9b68c35f-P028492","thread":"main","time":"2019-01-16T17:28:42.621027Z","file":"common-main.c","line":39,"t_abs":0.001173,"argv":["git","version"]}
     +-{"event":"cmd_name","sid":"20190408T191610.507018Z-H9b68c35f-P028492","thread":"main","time":"2019-01-16T17:28:42.621122Z","file":"git.c","line":432,"name":"version","hierarchy":"version"}
     +-{"event":"exit","sid":"20190408T191610.507018Z-H9b68c35f-P028492","thread":"main","time":"2019-01-16T17:28:42.621236Z","file":"git.c","line":662,"t_abs":0.001227,"code":0}
     +-{"event":"atexit","sid":"20190408T191610.507018Z-H9b68c35f-P028492","thread":"main","time":"2019-01-16T17:28:42.621268Z","file":"trace2/tr2_tgt_event.c","line":163,"t_abs":0.001265,"code":0}
     +-------------
     +-
      -== Enabling a Target
      -
      -A Trace2 Target is enabled when the corresponding environment variable
      -(`GIT_TR2`, `GIT_TR2_PERF`, or `GIT_TR2_EVENT`) is set.  The following
      -values are recognized.
     -+=== Enabling a Target
     - 
     +-
      -`0`::
      -`false`::
     -+To enable a target, set the corresponding environment variable or
     -+system or global config value to one of the following:
     - 
     --	Disables the target.
      -
     +-	Disables the target.
     + 
      -`1`::
      -`true`::
     --
     ++or
     + 
      -	Enables the target and writes stream to `STDERR`.
      -
      -`[2-9]`::
     --
     ++------------
     ++$ git config --global trace2.eventTarget ~/log.event
     ++$ git version
     ++git version 2.20.1.155.g426c96fcdb
     ++------------
     + 
      -	Enables the target and writes to the already opened file descriptor.
     --
     ++yields
     + 
      -`<absolute-pathname>`::
     --
     ++------------
     ++$ cat ~/log.event
     ++{"event":"version","sid":"sid":"20190408T191610.507018Z-H9b68c35f-P000059a8","thread":"main","time":"2019-01-16T17:28:42.620713Z","file":"common-main.c","line":38,"evt":"1","exe":"2.20.1.155.g426c96fcdb"}
     ++{"event":"start","sid":"20190408T191610.507018Z-H9b68c35f-P000059a8","thread":"main","time":"2019-01-16T17:28:42.621027Z","file":"common-main.c","line":39,"t_abs":0.001173,"argv":["git","version"]}
     ++{"event":"cmd_name","sid":"20190408T191610.507018Z-H9b68c35f-P000059a8","thread":"main","time":"2019-01-16T17:28:42.621122Z","file":"git.c","line":432,"name":"version","hierarchy":"version"}
     ++{"event":"exit","sid":"20190408T191610.507018Z-H9b68c35f-P000059a8","thread":"main","time":"2019-01-16T17:28:42.621236Z","file":"git.c","line":662,"t_abs":0.001227,"code":0}
     ++{"event":"atexit","sid":"20190408T191610.507018Z-H9b68c35f-P000059a8","thread":"main","time":"2019-01-16T17:28:42.621268Z","file":"trace2/tr2_tgt_event.c","line":163,"t_abs":0.001265,"code":0}
     ++------------
     + 
      -	Enables the target, opens and writes to the file in append mode.
     --
     ++=== Enabling a Target
     + 
      -`af_unix:[<socket_type>:]<absolute-pathname>`::
     --
     ++To enable a target, set the corresponding environment variable or
     ++system or global config value to one of the following:
     + 
      -	Enables the target, opens and writes to a Unix Domain Socket
      -	(on platforms that support them).
      -+
     @@ -316,6 +322,15 @@
       Each event is a JSON-object containing multiple key/value pairs
       written as a single line and followed by a LF.
       
     +@@
     + ------------
     + {
     + 	"event":"version",
     +-	"sid":"20190408T191827.272759Z-H9b68c35f-P011764",
     ++	"sid":"20190408T191827.272759Z-H9b68c35f-P00003510",
     + 	"thread":"main",
     + 	"time":"2019-04-08T19:18:27.282761Z",
     + 	"file":"common-main.c",
      @@
       `"repo":<repo-id>`::
       	when present, is the integer repo-id as described previously.

-- 
gitgitgadget

^ permalink raw reply	[flat|nested] 68+ messages in thread

* [PATCH v4 01/10] config: initialize opts structure in repo_read_config()
  2019-04-15 20:39     ` [PATCH v4 " Jeff Hostetler via GitGitGadget
@ 2019-04-15 20:39       ` Jeff Hostetler via GitGitGadget
  2019-04-15 20:39       ` [PATCH v4 02/10] trace2: refactor setting process starting time Jeff Hostetler via GitGitGadget
                         ` (9 subsequent siblings)
  10 siblings, 0 replies; 68+ messages in thread
From: Jeff Hostetler via GitGitGadget @ 2019-04-15 20:39 UTC (permalink / raw)
  To: git
  Cc: gitster, peff, jrnieder, steadmon, avarab, Junio C Hamano,
	Jeff Hostetler

From: Jeff Hostetler <jeffhost@microsoft.com>

Initialize opts structure in repo_read_config().

This change fixes a crash in later commit after a new field is added
to the structure.

In commit 3b256228a66f8587661481ef3e08259864f3ba2a, repo_read_config()
was added.  It only initializes 3 fields in the opts structure.  It is
passed to config_with_options() and then to do_git_config_sequence().
However, do_git_config_sequence() drops the opts on the floor and calls
git_config_from_file() rather than git_config_from_file_with_options(),
so that may be why this hasn't been a problem in the past.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Jeff Hostetler <jeffhost@microsoft.com>
---
 config.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/config.c b/config.c
index 0f0cdd8c0f..c809f76219 100644
--- a/config.c
+++ b/config.c
@@ -2011,7 +2011,7 @@ int git_configset_get_pathname(struct config_set *cs, const char *key, const cha
 /* Functions use to read configuration from a repository */
 static void repo_read_config(struct repository *repo)
 {
-	struct config_options opts;
+	struct config_options opts = { 0 };
 
 	opts.respect_includes = 1;
 	opts.commondir = repo->commondir;
-- 
gitgitgadget


^ permalink raw reply	[flat|nested] 68+ messages in thread

* [PATCH v4 02/10] trace2: refactor setting process starting time
  2019-04-15 20:39     ` [PATCH v4 " Jeff Hostetler via GitGitGadget
  2019-04-15 20:39       ` [PATCH v4 01/10] config: initialize opts structure in repo_read_config() Jeff Hostetler via GitGitGadget
@ 2019-04-15 20:39       ` Jeff Hostetler via GitGitGadget
  2019-04-15 20:39       ` [PATCH v4 03/10] trace2: add absolute elapsed time to start event Jeff Hostetler via GitGitGadget
                         ` (8 subsequent siblings)
  10 siblings, 0 replies; 68+ messages in thread
From: Jeff Hostetler via GitGitGadget @ 2019-04-15 20:39 UTC (permalink / raw)
  To: git
  Cc: gitster, peff, jrnieder, steadmon, avarab, Junio C Hamano,
	Jeff Hostetler

From: Jeff Hostetler <jeffhost@microsoft.com>

Create trace2_initialize_clock() and call from main() to capture
process start time in isolation and before other sub-systems are
ready.

Signed-off-by: Jeff Hostetler <jeffhost@microsoft.com>
---
 Documentation/technical/api-trace2.txt | 12 ++++++--
 common-main.c                          |  2 ++
 compat/mingw.c                         |  2 ++
 trace2.c                               |  7 ++++-
 trace2.h                               | 17 ++++++++++++
 trace2/tr2_tls.c                       | 38 ++++++++++++++++----------
 trace2/tr2_tls.h                       |  8 +++++-
 7 files changed, 67 insertions(+), 19 deletions(-)

diff --git a/Documentation/technical/api-trace2.txt b/Documentation/technical/api-trace2.txt
index 2de565fa3d..f37fccf1da 100644
--- a/Documentation/technical/api-trace2.txt
+++ b/Documentation/technical/api-trace2.txt
@@ -160,17 +160,23 @@ purposes.
 
 These are concerned with the lifetime of the overall git process.
 
+`void trace2_initialize_clock()`::
+
+	Initialize the Trace2 start clock and nothing else.  This should
+	be called at the very top of main() to capture the process start
+	time and reduce startup order dependencies.
+
 `void trace2_initialize()`::
 
 	Determines if any Trace2 Targets should be enabled and
-	initializes the Trace2 facility.  This includes starting the
-	elapsed time clocks and thread local storage (TLS).
+	initializes the Trace2 facility.  This includes setting up the
+	Trace2 thread local storage (TLS).
 +
 This function emits a "version" message containing the version of git
 and the Trace2 protocol.
 +
 This function should be called from `main()` as early as possible in
-the life of the process.
+the life of the process after essential process initialization.
 
 `int trace2_is_enabled()`::
 
diff --git a/common-main.c b/common-main.c
index d484aec209..6137af0e63 100644
--- a/common-main.c
+++ b/common-main.c
@@ -27,6 +27,8 @@ int main(int argc, const char **argv)
 {
 	int result;
 
+	trace2_initialize_clock();
+
 	/*
 	 * Always open file descriptors 0/1/2 to avoid clobbering files
 	 * in die().  It also avoids messing up when the pipes are dup'ed
diff --git a/compat/mingw.c b/compat/mingw.c
index 6b04514cdc..a2f74aca6a 100644
--- a/compat/mingw.c
+++ b/compat/mingw.c
@@ -2569,6 +2569,8 @@ void mingw_startup(void)
 	wchar_t **wenv, **wargv;
 	_startupinfo si;
 
+	trace2_initialize_clock();
+
 	maybe_redirect_std_handles();
 
 	/* get wide char arguments and environment */
diff --git a/trace2.c b/trace2.c
index ccccd4ef09..6dd51e6aa5 100644
--- a/trace2.c
+++ b/trace2.c
@@ -142,6 +142,11 @@ static void tr2main_signal_handler(int signo)
 	raise(signo);
 }
 
+void trace2_initialize_clock(void)
+{
+	tr2tls_start_process_clock();
+}
+
 void trace2_initialize_fl(const char *file, int line)
 {
 	struct tr2_tgt *tgt_j;
@@ -428,7 +433,7 @@ void trace2_thread_start_fl(const char *file, int line, const char *thread_name)
 	us_now = getnanotime() / 1000;
 	us_elapsed_absolute = tr2tls_absolute_elapsed(us_now);
 
-	tr2tls_create_self(thread_name);
+	tr2tls_create_self(thread_name, us_now);
 
 	for_each_wanted_builtin (j, tgt_j)
 		if (tgt_j->pfn_thread_start_fl)
diff --git a/trace2.h b/trace2.h
index ae5020d0e6..8f89e70c44 100644
--- a/trace2.h
+++ b/trace2.h
@@ -19,6 +19,23 @@ struct json_writer;
  * [] trace2_printf*    -- legacy trace[1] messages.
  */
 
+/*
+ * Initialize the TRACE2 clock and do nothing else, in particular
+ * no mallocs, no system inspection, and no environment inspection.
+ *
+ * This should be called at the very top of main() to capture the
+ * process start time.  This is intended to reduce chicken-n-egg
+ * bootstrap pressure.
+ *
+ * It is safe to call this more than once.  This allows capturing
+ * absolute startup costs on Windows which uses a little trickery
+ * to do setup work before common-main.c:main() is called.
+ *
+ * The main trace2_initialize_fl() may be called a little later
+ * after more infrastructure is established.
+ */
+void trace2_initialize_clock(void);
+
 /*
  * Initialize TRACE2 tracing facility if any of the builtin TRACE2
  * targets are enabled in the environment.  Emits a 'version' event.
diff --git a/trace2/tr2_tls.c b/trace2/tr2_tls.c
index 8e65b0361d..e76d8c5d92 100644
--- a/trace2/tr2_tls.c
+++ b/trace2/tr2_tls.c
@@ -10,16 +10,30 @@
 #define TR2_REGION_NESTING_INITIAL_SIZE (100)
 
 static struct tr2tls_thread_ctx *tr2tls_thread_main;
-static uint64_t tr2tls_us_start_main;
+static uint64_t tr2tls_us_start_process;
 
 static pthread_mutex_t tr2tls_mutex;
 static pthread_key_t tr2tls_key;
 
 static int tr2_next_thread_id; /* modify under lock */
 
-struct tr2tls_thread_ctx *tr2tls_create_self(const char *thread_name)
+void tr2tls_start_process_clock(void)
+{
+	if (tr2tls_us_start_process)
+		return;
+
+	/*
+	 * Keep the absolute start time of the process (i.e. the main
+	 * process) in a fixed variable since other threads need to
+	 * access it.  This allows them to do that without a lock on
+	 * main thread's array data (because of reallocs).
+	 */
+	tr2tls_us_start_process = getnanotime() / 1000;
+}
+
+struct tr2tls_thread_ctx *tr2tls_create_self(const char *thread_name,
+					     uint64_t us_thread_start)
 {
-	uint64_t us_now = getnanotime() / 1000;
 	struct tr2tls_thread_ctx *ctx = xcalloc(1, sizeof(*ctx));
 
 	/*
@@ -29,7 +43,7 @@ struct tr2tls_thread_ctx *tr2tls_create_self(const char *thread_name)
 	 */
 	ctx->alloc = TR2_REGION_NESTING_INITIAL_SIZE;
 	ctx->array_us_start = (uint64_t *)xcalloc(ctx->alloc, sizeof(uint64_t));
-	ctx->array_us_start[ctx->nr_open_regions++] = us_now;
+	ctx->array_us_start[ctx->nr_open_regions++] = us_thread_start;
 
 	ctx->thread_id = tr2tls_locked_increment(&tr2_next_thread_id);
 
@@ -55,7 +69,7 @@ struct tr2tls_thread_ctx *tr2tls_get_self(void)
 	 * here and silently continue.
 	 */
 	if (!ctx)
-		ctx = tr2tls_create_self("unknown");
+		ctx = tr2tls_create_self("unknown", getnanotime() / 1000);
 
 	return ctx;
 }
@@ -124,22 +138,18 @@ uint64_t tr2tls_absolute_elapsed(uint64_t us)
 	if (!tr2tls_thread_main)
 		return 0;
 
-	return us - tr2tls_us_start_main;
+	return us - tr2tls_us_start_process;
 }
 
 void tr2tls_init(void)
 {
+	tr2tls_start_process_clock();
+
 	pthread_key_create(&tr2tls_key, NULL);
 	init_recursive_mutex(&tr2tls_mutex);
 
-	tr2tls_thread_main = tr2tls_create_self("main");
-	/*
-	 * Keep a copy of the absolute start time of the main thread
-	 * in a fixed variable since other threads need to access it.
-	 * This also eliminates the need to lock accesses to the main
-	 * thread's array (because of reallocs).
-	 */
-	tr2tls_us_start_main = tr2tls_thread_main->array_us_start[0];
+	tr2tls_thread_main =
+		tr2tls_create_self("main", tr2tls_us_start_process);
 }
 
 void tr2tls_release(void)
diff --git a/trace2/tr2_tls.h b/trace2/tr2_tls.h
index bb80e3f8e7..b1e327a928 100644
--- a/trace2/tr2_tls.h
+++ b/trace2/tr2_tls.h
@@ -31,7 +31,8 @@ struct tr2tls_thread_ctx {
  * In this and all following functions the term "self" refers to the
  * current thread.
  */
-struct tr2tls_thread_ctx *tr2tls_create_self(const char *thread_name);
+struct tr2tls_thread_ctx *tr2tls_create_self(const char *thread_name,
+					     uint64_t us_thread_start);
 
 /*
  * Get our TLS data.
@@ -94,4 +95,9 @@ void tr2tls_release(void);
  */
 int tr2tls_locked_increment(int *p);
 
+/*
+ * Capture the process start time and do nothing else.
+ */
+void tr2tls_start_process_clock(void);
+
 #endif /* TR2_TLS_H */
-- 
gitgitgadget


^ permalink raw reply	[flat|nested] 68+ messages in thread

* [PATCH v4 03/10] trace2: add absolute elapsed time to start event
  2019-04-15 20:39     ` [PATCH v4 " Jeff Hostetler via GitGitGadget
  2019-04-15 20:39       ` [PATCH v4 01/10] config: initialize opts structure in repo_read_config() Jeff Hostetler via GitGitGadget
  2019-04-15 20:39       ` [PATCH v4 02/10] trace2: refactor setting process starting time Jeff Hostetler via GitGitGadget
@ 2019-04-15 20:39       ` Jeff Hostetler via GitGitGadget
  2019-04-15 20:39       ` [PATCH v4 04/10] trace2: find exec-dir before trace2 initialization Jeff Hostetler via GitGitGadget
                         ` (7 subsequent siblings)
  10 siblings, 0 replies; 68+ messages in thread
From: Jeff Hostetler via GitGitGadget @ 2019-04-15 20:39 UTC (permalink / raw)
  To: git
  Cc: gitster, peff, jrnieder, steadmon, avarab, Junio C Hamano,
	Jeff Hostetler

From: Jeff Hostetler <jeffhost@microsoft.com>

Add elapsed process time to "start" event to measure
the performance of early process startup.

Signed-off-by: Jeff Hostetler <jeffhost@microsoft.com>
---
 Documentation/technical/api-trace2.txt | 11 ++++++-----
 t/t0211-trace2-perf.sh                 | 12 ++++++------
 trace2.c                               |  8 +++++++-
 trace2/tr2_tgt.h                       |  1 +
 trace2/tr2_tgt_event.c                 |  5 ++++-
 trace2/tr2_tgt_normal.c                |  3 ++-
 trace2/tr2_tgt_perf.c                  |  7 ++++---
 7 files changed, 30 insertions(+), 17 deletions(-)

diff --git a/Documentation/technical/api-trace2.txt b/Documentation/technical/api-trace2.txt
index f37fccf1da..baaa1153bb 100644
--- a/Documentation/technical/api-trace2.txt
+++ b/Documentation/technical/api-trace2.txt
@@ -60,7 +60,7 @@ git version 2.20.1.155.g426c96fcdb
 ------------
 $ cat ~/log.perf
 12:28:42.620675 common-main.c:38                  | d0 | main                     | version      |     |           |           |            | 2.20.1.155.g426c96fcdb
-12:28:42.621001 common-main.c:39                  | d0 | main                     | start        |     |           |           |            | git version
+12:28:42.621001 common-main.c:39                  | d0 | main                     | start        |     |  0.001173 |           |            | git version
 12:28:42.621111 git.c:432                         | d0 | main                     | cmd_name     |     |           |           |            | version (version)
 12:28:42.621225 git.c:662                         | d0 | main                     | exit         |     |  0.001227 |           |            | code:0
 12:28:42.621259 trace2/tr2_tgt_perf.c:211         | d0 | main                     | atexit       |     |  0.001265 |           |            | code:0
@@ -79,7 +79,7 @@ git version 2.20.1.155.g426c96fcdb
 ------------
 $ cat ~/log.event
 {"event":"version","sid":"1547659722619736-11614","thread":"main","time":"2019-01-16 17:28:42.620713","file":"common-main.c","line":38,"evt":"1","exe":"2.20.1.155.g426c96fcdb"}
-{"event":"start","sid":"1547659722619736-11614","thread":"main","time":"2019-01-16 17:28:42.621027","file":"common-main.c","line":39,"argv":["git","version"]}
+{"event":"start","sid":"1547659722619736-11614","thread":"main","time":"2019-01-16 17:28:42.621027","file":"common-main.c","line":39,"t_abs":0.001173,"argv":["git","version"]}
 {"event":"cmd_name","sid":"1547659722619736-11614","thread":"main","time":"2019-01-16 17:28:42.621122","file":"git.c","line":432,"name":"version","hierarchy":"version"}
 {"event":"exit","sid":"1547659722619736-11614","thread":"main","time":"2019-01-16 17:28:42.621236","file":"git.c","line":662,"t_abs":0.001227,"code":0}
 {"event":"atexit","sid":"1547659722619736-11614","thread":"main","time":"2019-01-16 17:28:42.621268","file":"trace2/tr2_tgt_event.c","line":163,"t_abs":0.001265,"code":0}
@@ -601,6 +601,7 @@ from all events and the `time` field is only present on the "start" and
 {
 	"event":"start",
 	...
+	"t_abs":0.001227, # elapsed time in seconds
 	"argv":["git","version"]
 }
 ------------
@@ -1118,7 +1119,7 @@ $ git status
 
 $ cat ~/log.perf
 d0 | main                     | version      |     |           |           |            | 2.20.1.160.g5676107ecd.dirty
-d0 | main                     | start        |     |           |           |            | git status
+d0 | main                     | start        |     |  0.001173 |           |            | git status
 d0 | main                     | def_repo     | r1  |           |           |            | worktree:/Users/jeffhost/work/gfw
 d0 | main                     | cmd_name     |     |           |           |            | status (status)
 ...
@@ -1163,7 +1164,7 @@ $ git status
 ...
 $ cat ~/log.perf
 d0 | main                     | version      |     |           |           |            | 2.20.1.162.gb4ccea44db.dirty
-d0 | main                     | start        |     |           |           |            | git status
+d0 | main                     | start        |     |  0.001173 |           |            | git status
 d0 | main                     | def_repo     | r1  |           |           |            | worktree:/Users/jeffhost/work/gfw
 d0 | main                     | cmd_name     |     |           |           |            | status (status)
 ...
@@ -1219,7 +1220,7 @@ $ git status
 ...
 $ cat ~/log.perf
 d0 | main                     | version      |     |           |           |            | 2.20.1.156.gf9916ae094.dirty
-d0 | main                     | start        |     |           |           |            | git status
+d0 | main                     | start        |     |  0.001173 |           |            | git status
 d0 | main                     | def_repo     | r1  |           |           |            | worktree:/Users/jeffhost/work/gfw
 d0 | main                     | cmd_name     |     |           |           |            | status (status)
 d0 | main                     | region_enter | r1  |  0.001791 |           | index      | label:do_read_index .git/index
diff --git a/t/t0211-trace2-perf.sh b/t/t0211-trace2-perf.sh
index 953e2f7847..c9694b29f7 100755
--- a/t/t0211-trace2-perf.sh
+++ b/t/t0211-trace2-perf.sh
@@ -50,7 +50,7 @@ test_expect_success 'perf stream, return code 0' '
 	perl "$TEST_DIRECTORY/t0211/scrub_perf.perl" <trace.perf >actual &&
 	cat >expect <<-EOF &&
 		d0|main|version|||||$V
-		d0|main|start|||||_EXE_ trace2 001return 0
+		d0|main|start||_T_ABS_|||_EXE_ trace2 001return 0
 		d0|main|cmd_name|||||trace2 (trace2)
 		d0|main|exit||_T_ABS_|||code:0
 		d0|main|atexit||_T_ABS_|||code:0
@@ -64,7 +64,7 @@ test_expect_success 'perf stream, return code 1' '
 	perl "$TEST_DIRECTORY/t0211/scrub_perf.perl" <trace.perf >actual &&
 	cat >expect <<-EOF &&
 		d0|main|version|||||$V
-		d0|main|start|||||_EXE_ trace2 001return 1
+		d0|main|start||_T_ABS_|||_EXE_ trace2 001return 1
 		d0|main|cmd_name|||||trace2 (trace2)
 		d0|main|exit||_T_ABS_|||code:1
 		d0|main|atexit||_T_ABS_|||code:1
@@ -82,7 +82,7 @@ test_expect_success 'perf stream, error event' '
 	perl "$TEST_DIRECTORY/t0211/scrub_perf.perl" <trace.perf >actual &&
 	cat >expect <<-EOF &&
 		d0|main|version|||||$V
-		d0|main|start|||||_EXE_ trace2 003error '\''hello world'\'' '\''this is a test'\''
+		d0|main|start||_T_ABS_|||_EXE_ trace2 003error '\''hello world'\'' '\''this is a test'\''
 		d0|main|cmd_name|||||trace2 (trace2)
 		d0|main|error|||||hello world
 		d0|main|error|||||this is a test
@@ -128,15 +128,15 @@ test_expect_success 'perf stream, child processes' '
 	perl "$TEST_DIRECTORY/t0211/scrub_perf.perl" <trace.perf >actual &&
 	cat >expect <<-EOF &&
 		d0|main|version|||||$V
-		d0|main|start|||||_EXE_ trace2 004child test-tool trace2 004child test-tool trace2 001return 0
+		d0|main|start||_T_ABS_|||_EXE_ trace2 004child test-tool trace2 004child test-tool trace2 001return 0
 		d0|main|cmd_name|||||trace2 (trace2)
 		d0|main|child_start||_T_ABS_|||[ch0] class:? argv: test-tool trace2 004child test-tool trace2 001return 0
 		d1|main|version|||||$V
-		d1|main|start|||||_EXE_ trace2 004child test-tool trace2 001return 0
+		d1|main|start||_T_ABS_|||_EXE_ trace2 004child test-tool trace2 001return 0
 		d1|main|cmd_name|||||trace2 (trace2/trace2)
 		d1|main|child_start||_T_ABS_|||[ch0] class:? argv: test-tool trace2 001return 0
 		d2|main|version|||||$V
-		d2|main|start|||||_EXE_ trace2 001return 0
+		d2|main|start||_T_ABS_|||_EXE_ trace2 001return 0
 		d2|main|cmd_name|||||trace2 (trace2/trace2/trace2)
 		d2|main|exit||_T_ABS_|||code:0
 		d2|main|atexit||_T_ABS_|||code:0
diff --git a/trace2.c b/trace2.c
index 6dd51e6aa5..1c180062dd 100644
--- a/trace2.c
+++ b/trace2.c
@@ -182,13 +182,19 @@ void trace2_cmd_start_fl(const char *file, int line, const char **argv)
 {
 	struct tr2_tgt *tgt_j;
 	int j;
+	uint64_t us_now;
+	uint64_t us_elapsed_absolute;
 
 	if (!trace2_enabled)
 		return;
 
+	us_now = getnanotime() / 1000;
+	us_elapsed_absolute = tr2tls_absolute_elapsed(us_now);
+
 	for_each_wanted_builtin (j, tgt_j)
 		if (tgt_j->pfn_start_fl)
-			tgt_j->pfn_start_fl(file, line, argv);
+			tgt_j->pfn_start_fl(file, line, us_elapsed_absolute,
+					    argv);
 }
 
 int trace2_cmd_exit_fl(const char *file, int line, int code)
diff --git a/trace2/tr2_tgt.h b/trace2/tr2_tgt.h
index 297bb8ffbe..7b90469212 100644
--- a/trace2/tr2_tgt.h
+++ b/trace2/tr2_tgt.h
@@ -15,6 +15,7 @@ typedef void(tr2_tgt_term_t)(void);
 typedef void(tr2_tgt_evt_version_fl_t)(const char *file, int line);
 
 typedef void(tr2_tgt_evt_start_fl_t)(const char *file, int line,
+				     uint64_t us_elapsed_absolute,
 				     const char **argv);
 typedef void(tr2_tgt_evt_exit_fl_t)(const char *file, int line,
 				    uint64_t us_elapsed_absolute, int code);
diff --git a/trace2/tr2_tgt_event.c b/trace2/tr2_tgt_event.c
index 107cb5317d..89a4d3ae9a 100644
--- a/trace2/tr2_tgt_event.c
+++ b/trace2/tr2_tgt_event.c
@@ -122,13 +122,16 @@ static void fn_version_fl(const char *file, int line)
 	jw_release(&jw);
 }
 
-static void fn_start_fl(const char *file, int line, const char **argv)
+static void fn_start_fl(const char *file, int line,
+			uint64_t us_elapsed_absolute, const char **argv)
 {
 	const char *event_name = "start";
 	struct json_writer jw = JSON_WRITER_INIT;
+	double t_abs = (double)us_elapsed_absolute / 1000000.0;
 
 	jw_object_begin(&jw, 0);
 	event_fmt_prepare(event_name, file, line, NULL, &jw);
+	jw_object_double(&jw, "t_abs", 6, t_abs);
 	jw_object_inline_begin_array(&jw, "argv");
 	jw_array_argv(&jw, argv);
 	jw_end(&jw);
diff --git a/trace2/tr2_tgt_normal.c b/trace2/tr2_tgt_normal.c
index 547183d5b6..57f3e18f5b 100644
--- a/trace2/tr2_tgt_normal.c
+++ b/trace2/tr2_tgt_normal.c
@@ -81,7 +81,8 @@ static void fn_version_fl(const char *file, int line)
 	strbuf_release(&buf_payload);
 }
 
-static void fn_start_fl(const char *file, int line, const char **argv)
+static void fn_start_fl(const char *file, int line,
+			uint64_t us_elapsed_absolute, const char **argv)
 {
 	struct strbuf buf_payload = STRBUF_INIT;
 
diff --git a/trace2/tr2_tgt_perf.c b/trace2/tr2_tgt_perf.c
index f0746fcf86..9c3b4d8a0f 100644
--- a/trace2/tr2_tgt_perf.c
+++ b/trace2/tr2_tgt_perf.c
@@ -159,15 +159,16 @@ static void fn_version_fl(const char *file, int line)
 	strbuf_release(&buf_payload);
 }
 
-static void fn_start_fl(const char *file, int line, const char **argv)
+static void fn_start_fl(const char *file, int line,
+			uint64_t us_elapsed_absolute, const char **argv)
 {
 	const char *event_name = "start";
 	struct strbuf buf_payload = STRBUF_INIT;
 
 	sq_quote_argv_pretty(&buf_payload, argv);
 
-	perf_io_write_fl(file, line, event_name, NULL, NULL, NULL, NULL,
-			 &buf_payload);
+	perf_io_write_fl(file, line, event_name, NULL, &us_elapsed_absolute,
+			 NULL, NULL, &buf_payload);
 	strbuf_release(&buf_payload);
 }
 
-- 
gitgitgadget


^ permalink raw reply	[flat|nested] 68+ messages in thread

* [PATCH v4 04/10] trace2: find exec-dir before trace2 initialization
  2019-04-15 20:39     ` [PATCH v4 " Jeff Hostetler via GitGitGadget
                         ` (2 preceding siblings ...)
  2019-04-15 20:39       ` [PATCH v4 03/10] trace2: add absolute elapsed time to start event Jeff Hostetler via GitGitGadget
@ 2019-04-15 20:39       ` Jeff Hostetler via GitGitGadget
  2019-04-15 20:39       ` [PATCH v4 05/10] config: add read_very_early_config() Jeff Hostetler via GitGitGadget
                         ` (6 subsequent siblings)
  10 siblings, 0 replies; 68+ messages in thread
From: Jeff Hostetler via GitGitGadget @ 2019-04-15 20:39 UTC (permalink / raw)
  To: git
  Cc: gitster, peff, jrnieder, steadmon, avarab, Junio C Hamano,
	Jeff Hostetler

From: Jeff Hostetler <jeffhost@microsoft.com>

Teach Git to resolve the executable directory before initializing
Trace2.  This allows the system configuration directory to be
discovered earlier (because it is sometimes relative to the prefix
or runtime-prefix).

This will be used by the next commit to allow trace2 settings to
be loaded from the system config.

Signed-off-by: Jeff Hostetler <jeffhost@microsoft.com>
---
 common-main.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/common-main.c b/common-main.c
index 6137af0e63..299ca62a72 100644
--- a/common-main.c
+++ b/common-main.c
@@ -37,12 +37,12 @@ int main(int argc, const char **argv)
 	sanitize_stdfds();
 	restore_sigpipe_to_default();
 
+	git_resolve_executable_dir(argv[0]);
+
 	trace2_initialize();
 	trace2_cmd_start(argv);
 	trace2_collect_process_info();
 
-	git_resolve_executable_dir(argv[0]);
-
 	git_setup_gettext();
 
 	initialize_the_repository();
-- 
gitgitgadget


^ permalink raw reply	[flat|nested] 68+ messages in thread

* [PATCH v4 05/10] config: add read_very_early_config()
  2019-04-15 20:39     ` [PATCH v4 " Jeff Hostetler via GitGitGadget
                         ` (3 preceding siblings ...)
  2019-04-15 20:39       ` [PATCH v4 04/10] trace2: find exec-dir before trace2 initialization Jeff Hostetler via GitGitGadget
@ 2019-04-15 20:39       ` Jeff Hostetler via GitGitGadget
  2019-04-15 20:39       ` [PATCH v4 06/10] trace2: use system/global config for default trace2 settings Jeff Hostetler via GitGitGadget
                         ` (5 subsequent siblings)
  10 siblings, 0 replies; 68+ messages in thread
From: Jeff Hostetler via GitGitGadget @ 2019-04-15 20:39 UTC (permalink / raw)
  To: git
  Cc: gitster, peff, jrnieder, steadmon, avarab, Junio C Hamano,
	Jeff Hostetler

From: Jeff Hostetler <jeffhost@microsoft.com>

Created an even lighter version of read_early_config() that
only looks at system and global config settings.  It omits
repo-local, worktree-local, and command-line settings.

Signed-off-by: Jeff Hostetler <jeffhost@microsoft.com>
---
 config.c | 23 ++++++++++++++++++++---
 config.h |  4 ++++
 2 files changed, 24 insertions(+), 3 deletions(-)

diff --git a/config.c b/config.c
index c809f76219..d7a08713a8 100644
--- a/config.c
+++ b/config.c
@@ -1688,14 +1688,15 @@ static int do_git_config_sequence(const struct config_options *opts,
 		ret += git_config_from_file(fn, user_config, data);
 
 	current_parsing_scope = CONFIG_SCOPE_REPO;
-	if (repo_config && !access_or_die(repo_config, R_OK, 0))
+	if (!opts->ignore_repo && repo_config &&
+	    !access_or_die(repo_config, R_OK, 0))
 		ret += git_config_from_file(fn, repo_config, data);
 
 	/*
 	 * Note: this should have a new scope, CONFIG_SCOPE_WORKTREE.
 	 * But let's not complicate things before it's actually needed.
 	 */
-	if (repository_format_worktree_config) {
+	if (!opts->ignore_worktree && repository_format_worktree_config) {
 		char *path = git_pathdup("config.worktree");
 		if (!access_or_die(path, R_OK, 0))
 			ret += git_config_from_file(fn, path, data);
@@ -1703,7 +1704,7 @@ static int do_git_config_sequence(const struct config_options *opts,
 	}
 
 	current_parsing_scope = CONFIG_SCOPE_CMDLINE;
-	if (git_config_from_parameters(fn, data) < 0)
+	if (!opts->ignore_cmdline && git_config_from_parameters(fn, data) < 0)
 		die(_("unable to parse command-line config"));
 
 	current_parsing_scope = CONFIG_SCOPE_UNKNOWN;
@@ -1794,6 +1795,22 @@ void read_early_config(config_fn_t cb, void *data)
 	strbuf_release(&gitdir);
 }
 
+/*
+ * Read config but only enumerate system and global settings.
+ * Omit any repo-local, worktree-local, or command-line settings.
+ */
+void read_very_early_config(config_fn_t cb, void *data)
+{
+	struct config_options opts = { 0 };
+
+	opts.respect_includes = 1;
+	opts.ignore_repo = 1;
+	opts.ignore_worktree = 1;
+	opts.ignore_cmdline = 1;
+
+	config_with_options(cb, data, NULL, &opts);
+}
+
 static struct config_set_element *configset_find_element(struct config_set *cs, const char *key)
 {
 	struct config_set_element k;
diff --git a/config.h b/config.h
index ee5d3fa7b4..6a58d61d22 100644
--- a/config.h
+++ b/config.h
@@ -55,6 +55,9 @@ typedef int (*config_parser_event_fn_t)(enum config_event_t type,
 
 struct config_options {
 	unsigned int respect_includes : 1;
+	unsigned int ignore_repo : 1;
+	unsigned int ignore_worktree : 1;
+	unsigned int ignore_cmdline : 1;
 	const char *commondir;
 	const char *git_dir;
 	config_parser_event_fn_t event_fn;
@@ -83,6 +86,7 @@ extern int git_config_from_blob_oid(config_fn_t fn, const char *name,
 extern void git_config_push_parameter(const char *text);
 extern int git_config_from_parameters(config_fn_t fn, void *data);
 extern void read_early_config(config_fn_t cb, void *data);
+extern void read_very_early_config(config_fn_t cb, void *data);
 extern void git_config(config_fn_t fn, void *);
 extern int config_with_options(config_fn_t fn, void *,
 			       struct git_config_source *config_source,
-- 
gitgitgadget


^ permalink raw reply	[flat|nested] 68+ messages in thread

* [PATCH v4 06/10] trace2: use system/global config for default trace2 settings
  2019-04-15 20:39     ` [PATCH v4 " Jeff Hostetler via GitGitGadget
                         ` (4 preceding siblings ...)
  2019-04-15 20:39       ` [PATCH v4 05/10] config: add read_very_early_config() Jeff Hostetler via GitGitGadget
@ 2019-04-15 20:39       ` Jeff Hostetler via GitGitGadget
  2019-04-27 13:43         ` SZEDER Gábor
  2019-04-15 20:39       ` [PATCH v4 08/10] trace2: clarify UTC datetime formatting Jeff Hostetler via GitGitGadget
                         ` (4 subsequent siblings)
  10 siblings, 1 reply; 68+ messages in thread
From: Jeff Hostetler via GitGitGadget @ 2019-04-15 20:39 UTC (permalink / raw)
  To: git
  Cc: gitster, peff, jrnieder, steadmon, avarab, Junio C Hamano,
	Jeff Hostetler

From: Jeff Hostetler <jeffhost@microsoft.com>

Teach git to read the system and global config files for
default Trace2 settings.  This allows system-wide Trace2 settings to
be installed and inherited to make it easier to manage a collection of
systems.

The original GIT_TR2* environment variables are loaded afterwards and
can be used to override the system settings.

Only the system and global config files are used.  Repo and worktree
local config files are ignored.  Likewise, the "-c" command line
arguments are also ignored.  These limits are for performance reasons.

(1) For users not using Trace2, there should be minimal overhead to
detect that Trace2 is not enabled.  In particular, Trace2 should not
allocate lots of otherwise unused data strucutres.

(2) For accurate performance measurements, Trace2 should be initialized
as early in the git process as possible, and before most of the normal
git process initialization (which involves discovering the .git directory
and reading a hierarchy of config files).

Signed-off-by: Jeff Hostetler <jeffhost@microsoft.com>
---
 Makefile                 |   1 +
 t/t0210-trace2-normal.sh |  49 +++++++++++++--
 t/t0211-trace2-perf.sh   |  31 ++++++++--
 t/t0212-trace2-event.sh  |  42 +++++++++++--
 trace2.c                 |   4 ++
 trace2.h                 |  12 ++--
 trace2/tr2_cfg.c         |   7 +--
 trace2/tr2_dst.c         |  26 ++++----
 trace2/tr2_dst.h         |   3 +-
 trace2/tr2_sysenv.c      | 127 +++++++++++++++++++++++++++++++++++++++
 trace2/tr2_sysenv.h      |  36 +++++++++++
 trace2/tr2_tgt_event.c   |  46 +++++++-------
 trace2/tr2_tgt_normal.c  |  16 ++---
 trace2/tr2_tgt_perf.c    |  16 ++---
 14 files changed, 340 insertions(+), 76 deletions(-)
 create mode 100644 trace2/tr2_sysenv.c
 create mode 100644 trace2/tr2_sysenv.h

diff --git a/Makefile b/Makefile
index 3e03290d8f..9ddfa3dfe7 100644
--- a/Makefile
+++ b/Makefile
@@ -1005,6 +1005,7 @@ LIB_OBJS += trace2/tr2_cfg.o
 LIB_OBJS += trace2/tr2_cmd_name.o
 LIB_OBJS += trace2/tr2_dst.o
 LIB_OBJS += trace2/tr2_sid.o
+LIB_OBJS += trace2/tr2_sysenv.o
 LIB_OBJS += trace2/tr2_tbuf.o
 LIB_OBJS += trace2/tr2_tgt_event.o
 LIB_OBJS += trace2/tr2_tgt_normal.o
diff --git a/t/t0210-trace2-normal.sh b/t/t0210-trace2-normal.sh
index 03a0aedb1d..8d17e1e6f1 100755
--- a/t/t0210-trace2-normal.sh
+++ b/t/t0210-trace2-normal.sh
@@ -3,6 +3,11 @@
 test_description='test trace2 facility (normal target)'
 . ./test-lib.sh
 
+# Turn off any inherited trace2 settings for this test.
+sane_unset GIT_TR2 GIT_TR2_PERF GIT_TR2_EVENT
+sane_unset GIT_TR2_BRIEF
+sane_unset GIT_TR2_CONFIG_PARAMS
+
 # Add t/helper directory to PATH so that we can use a relative
 # path to run nested instances of test-tool.exe (see 004child).
 # This helps with HEREDOC comparisons later.
@@ -15,11 +20,6 @@ PATH="$TTDIR:$PATH" && export PATH
 # Warning: So you may see extra lines in artifact files when
 # Warning: interactively debugging.
 
-# Turn off any inherited trace2 settings for this test.
-unset GIT_TR2 GIT_TR2_PERF GIT_TR2_EVENT
-unset GIT_TR2_BRIEF
-unset GIT_TR2_CONFIG_PARAMS
-
 V=$(git version | sed -e 's/^git version //') && export V
 
 # There are multiple trace2 targets: normal, perf, and event.
@@ -132,4 +132,43 @@ test_expect_success 'normal stream, error event' '
 	test_cmp expect actual
 '
 
+sane_unset GIT_TR2_BRIEF
+
+# Now test without environment variables and get all Trace2 settings
+# from the global config.
+
+test_expect_success 'using global config, normal stream, return code 0' '
+	test_when_finished "rm trace.normal actual expect" &&
+	test_config_global trace2.normalBrief 1 &&
+	test_config_global trace2.normalTarget "$(pwd)/trace.normal" &&
+	test-tool trace2 001return 0 &&
+	perl "$TEST_DIRECTORY/t0210/scrub_normal.perl" <trace.normal >actual &&
+	cat >expect <<-EOF &&
+		version $V
+		start _EXE_ trace2 001return 0
+		cmd_name trace2 (trace2)
+		exit elapsed:_TIME_ code:0
+		atexit elapsed:_TIME_ code:0
+	EOF
+	test_cmp expect actual
+'
+
+test_expect_success 'using global config with include' '
+	test_when_finished "rm trace.normal actual expect real.gitconfig" &&
+	test_config_global trace2.normalBrief 1 &&
+	test_config_global trace2.normalTarget "$(pwd)/trace.normal" &&
+	mv "$(pwd)/.gitconfig" "$(pwd)/real.gitconfig" &&
+	test_config_global include.path "$(pwd)/real.gitconfig" &&
+	test-tool trace2 001return 0 &&
+	perl "$TEST_DIRECTORY/t0210/scrub_normal.perl" <trace.normal >actual &&
+	cat >expect <<-EOF &&
+		version $V
+		start _EXE_ trace2 001return 0
+		cmd_name trace2 (trace2)
+		exit elapsed:_TIME_ code:0
+		atexit elapsed:_TIME_ code:0
+	EOF
+	test_cmp expect actual
+'
+
 test_done
diff --git a/t/t0211-trace2-perf.sh b/t/t0211-trace2-perf.sh
index c9694b29f7..b501e867af 100755
--- a/t/t0211-trace2-perf.sh
+++ b/t/t0211-trace2-perf.sh
@@ -3,6 +3,11 @@
 test_description='test trace2 facility (perf target)'
 . ./test-lib.sh
 
+# Turn off any inherited trace2 settings for this test.
+sane_unset GIT_TR2 GIT_TR2_PERF GIT_TR2_EVENT
+sane_unset GIT_TR2_PERF_BRIEF
+sane_unset GIT_TR2_CONFIG_PARAMS
+
 # Add t/helper directory to PATH so that we can use a relative
 # path to run nested instances of test-tool.exe (see 004child).
 # This helps with HEREDOC comparisons later.
@@ -15,11 +20,6 @@ PATH="$TTDIR:$PATH" && export PATH
 # Warning: So you may see extra lines in artifact files when
 # Warning: interactively debugging.
 
-# Turn off any inherited trace2 settings for this test.
-unset GIT_TR2 GIT_TR2_PERF GIT_TR2_EVENT
-unset GIT_TR2_PERF_BRIEF
-unset GIT_TR2_CONFIG_PARAMS
-
 V=$(git version | sed -e 's/^git version //') && export V
 
 # There are multiple trace2 targets: normal, perf, and event.
@@ -150,4 +150,25 @@ test_expect_success 'perf stream, child processes' '
 	test_cmp expect actual
 '
 
+sane_unset GIT_TR2_PERF_BRIEF
+
+# Now test without environment variables and get all Trace2 settings
+# from the global config.
+
+test_expect_success 'using global config, perf stream, return code 0' '
+	test_when_finished "rm trace.perf actual expect" &&
+	test_config_global trace2.perfBrief 1 &&
+	test_config_global trace2.perfTarget "$(pwd)/trace.perf" &&
+	test-tool trace2 001return 0 &&
+	perl "$TEST_DIRECTORY/t0211/scrub_perf.perl" <trace.perf >actual &&
+	cat >expect <<-EOF &&
+		d0|main|version|||||$V
+		d0|main|start||_T_ABS_|||_EXE_ trace2 001return 0
+		d0|main|cmd_name|||||trace2 (trace2)
+		d0|main|exit||_T_ABS_|||code:0
+		d0|main|atexit||_T_ABS_|||code:0
+	EOF
+	test_cmp expect actual
+'
+
 test_done
diff --git a/t/t0212-trace2-event.sh b/t/t0212-trace2-event.sh
index 028b6c5671..59adae8123 100755
--- a/t/t0212-trace2-event.sh
+++ b/t/t0212-trace2-event.sh
@@ -3,6 +3,11 @@
 test_description='test trace2 facility'
 . ./test-lib.sh
 
+# Turn off any inherited trace2 settings for this test.
+sane_unset GIT_TR2 GIT_TR2_PERF GIT_TR2_EVENT
+sane_unset GIT_TR2_BARE
+sane_unset GIT_TR2_CONFIG_PARAMS
+
 perl -MJSON::PP -e 0 >/dev/null 2>&1 && test_set_prereq JSON_PP
 
 # Add t/helper directory to PATH so that we can use a relative
@@ -17,11 +22,6 @@ PATH="$TTDIR:$PATH" && export PATH
 # Warning: So you may see extra lines in artifact files when
 # Warning: interactively debugging.
 
-# Turn off any inherited trace2 settings for this test.
-unset GIT_TR2 GIT_TR2_PERF GIT_TR2_EVENT
-unset GIT_TR2_BARE
-unset GIT_TR2_CONFIG_PARAMS
-
 V=$(git version | sed -e 's/^git version //') && export V
 
 # There are multiple trace2 targets: normal, perf, and event.
@@ -233,4 +233,36 @@ test_expect_success JSON_PP 'basic trace2_data' '
 	test_cmp expect actual
 '
 
+# Now test without environment variables and get all Trace2 settings
+# from the global config.
+
+test_expect_success JSON_PP 'using global config, event stream, error event' '
+	test_when_finished "rm trace.event actual expect" &&
+	test_config_global trace2.eventTarget "$(pwd)/trace.event" &&
+	test-tool trace2 003error "hello world" "this is a test" &&
+	perl "$TEST_DIRECTORY/t0212/parse_events.perl" <trace.event >actual &&
+	sed -e "s/^|//" >expect <<-EOF &&
+	|VAR1 = {
+	|  "_SID0_":{
+	|    "argv":[
+	|      "_EXE_",
+	|      "trace2",
+	|      "003error",
+	|      "hello world",
+	|      "this is a test"
+	|    ],
+	|    "errors":[
+	|      "%s",
+	|      "%s"
+	|    ],
+	|    "exit_code":0,
+	|    "hierarchy":"trace2",
+	|    "name":"trace2",
+	|    "version":"$V"
+	|  }
+	|};
+	EOF
+	test_cmp expect actual
+'
+
 test_done
diff --git a/trace2.c b/trace2.c
index 1c180062dd..490b3f071e 100644
--- a/trace2.c
+++ b/trace2.c
@@ -10,6 +10,7 @@
 #include "trace2/tr2_cmd_name.h"
 #include "trace2/tr2_dst.h"
 #include "trace2/tr2_sid.h"
+#include "trace2/tr2_sysenv.h"
 #include "trace2/tr2_tgt.h"
 #include "trace2/tr2_tls.h"
 
@@ -120,6 +121,7 @@ static void tr2main_atexit_handler(void)
 	tr2_sid_release();
 	tr2_cmd_name_release();
 	tr2_cfg_free_patterns();
+	tr2_sysenv_release();
 
 	trace2_enabled = 0;
 }
@@ -155,6 +157,8 @@ void trace2_initialize_fl(const char *file, int line)
 	if (trace2_enabled)
 		return;
 
+	tr2_sysenv_load();
+
 	if (!tr2_tgt_want_builtins())
 		return;
 	trace2_enabled = 1;
diff --git a/trace2.h b/trace2.h
index 8f89e70c44..894bfca7e0 100644
--- a/trace2.h
+++ b/trace2.h
@@ -38,7 +38,8 @@ void trace2_initialize_clock(void);
 
 /*
  * Initialize TRACE2 tracing facility if any of the builtin TRACE2
- * targets are enabled in the environment.  Emits a 'version' event.
+ * targets are enabled in the system config or the environment.
+ * Emits a 'version' event.
  *
  * Cleanup/Termination is handled automatically by a registered
  * atexit() routine.
@@ -125,10 +126,11 @@ void trace2_cmd_alias_fl(const char *file, int line, const char *alias,
  * Emit one or more 'def_param' events for "interesting" configuration
  * settings.
  *
- * The environment variable "GIT_TR2_CONFIG_PARAMS" can be set to a
- * list of patterns considered important.  For example:
- *
- *    GIT_TR2_CONFIG_PARAMS="core.*,remote.*.url"
+ * Use the TR2_SYSENV_CFG_PARAM setting to register a comma-separated
+ * list of patterns configured important.  For example:
+ *     git config --system trace2.configParams 'core.*,remote.*.url'
+ * or:
+ *     GIT_TR2_CONFIG_PARAMS=core.*,remote.*.url"
  *
  * Note: this routine does a read-only iteration on the config data
  * (using read_early_config()), so it must not be called until enough
diff --git a/trace2/tr2_cfg.c b/trace2/tr2_cfg.c
index b329921ac5..caa7f06948 100644
--- a/trace2/tr2_cfg.c
+++ b/trace2/tr2_cfg.c
@@ -1,8 +1,7 @@
 #include "cache.h"
 #include "config.h"
-#include "tr2_cfg.h"
-
-#define TR2_ENVVAR_CFG_PARAM "GIT_TR2_CONFIG_PARAMS"
+#include "trace2/tr2_cfg.h"
+#include "trace2/tr2_sysenv.h"
 
 static struct strbuf **tr2_cfg_patterns;
 static int tr2_cfg_count_patterns;
@@ -21,7 +20,7 @@ static int tr2_cfg_load_patterns(void)
 		return tr2_cfg_count_patterns;
 	tr2_cfg_loaded = 1;
 
-	envvar = getenv(TR2_ENVVAR_CFG_PARAM);
+	envvar = tr2_sysenv_get(TR2_SYSENV_CFG_PARAM);
 	if (!envvar || !*envvar)
 		return tr2_cfg_count_patterns;
 
diff --git a/trace2/tr2_dst.c b/trace2/tr2_dst.c
index fd490a43ad..7d96f33420 100644
--- a/trace2/tr2_dst.c
+++ b/trace2/tr2_dst.c
@@ -1,5 +1,6 @@
 #include "cache.h"
 #include "trace2/tr2_dst.h"
+#include "trace2/tr2_sysenv.h"
 
 /*
  * If a Trace2 target cannot be opened for writing, we should issue a
@@ -7,17 +8,13 @@
  * or socket and beyond the user's control -- especially since every
  * git command (and sub-command) will print the message.  So we silently
  * eat these warnings and just discard the trace data.
- *
- * Enable the following environment variable to see these warnings.
  */
-#define TR2_ENVVAR_DST_DEBUG "GIT_TR2_DST_DEBUG"
-
 static int tr2_dst_want_warning(void)
 {
 	static int tr2env_dst_debug = -1;
 
 	if (tr2env_dst_debug == -1) {
-		const char *env_value = getenv(TR2_ENVVAR_DST_DEBUG);
+		const char *env_value = tr2_sysenv_get(TR2_SYSENV_DST_DEBUG);
 		if (!env_value || !*env_value)
 			tr2env_dst_debug = 0;
 		else
@@ -42,7 +39,9 @@ static int tr2_dst_try_path(struct tr2_dst *dst, const char *tgt_value)
 	if (fd == -1) {
 		if (tr2_dst_want_warning())
 			warning("trace2: could not open '%s' for '%s' tracing: %s",
-				tgt_value, dst->env_var_name, strerror(errno));
+				tgt_value,
+				tr2_sysenv_display_name(dst->sysenv_var),
+				strerror(errno));
 
 		tr2_dst_trace_disable(dst);
 		return 0;
@@ -116,7 +115,8 @@ static int tr2_dst_try_unix_domain_socket(struct tr2_dst *dst,
 	if (!path || !*path) {
 		if (tr2_dst_want_warning())
 			warning("trace2: invalid AF_UNIX value '%s' for '%s' tracing",
-				tgt_value, dst->env_var_name);
+				tgt_value,
+				tr2_sysenv_display_name(dst->sysenv_var));
 
 		tr2_dst_trace_disable(dst);
 		return 0;
@@ -126,7 +126,7 @@ static int tr2_dst_try_unix_domain_socket(struct tr2_dst *dst,
 	    strlen(path) >= sizeof(((struct sockaddr_un *)0)->sun_path)) {
 		if (tr2_dst_want_warning())
 			warning("trace2: invalid AF_UNIX path '%s' for '%s' tracing",
-				path, dst->env_var_name);
+				path, tr2_sysenv_display_name(dst->sysenv_var));
 
 		tr2_dst_trace_disable(dst);
 		return 0;
@@ -148,7 +148,8 @@ static int tr2_dst_try_unix_domain_socket(struct tr2_dst *dst,
 error:
 	if (tr2_dst_want_warning())
 		warning("trace2: could not connect to socket '%s' for '%s' tracing: %s",
-			path, dst->env_var_name, strerror(e));
+			path, tr2_sysenv_display_name(dst->sysenv_var),
+			strerror(e));
 
 	tr2_dst_trace_disable(dst);
 	return 0;
@@ -168,7 +169,7 @@ static void tr2_dst_malformed_warning(struct tr2_dst *dst,
 	struct strbuf buf = STRBUF_INIT;
 
 	strbuf_addf(&buf, "trace2: unknown value for '%s': '%s'",
-		    dst->env_var_name, tgt_value);
+		    tr2_sysenv_display_name(dst->sysenv_var), tgt_value);
 	warning("%s", buf.buf);
 
 	strbuf_release(&buf);
@@ -184,7 +185,7 @@ int tr2_dst_get_trace_fd(struct tr2_dst *dst)
 
 	dst->initialized = 1;
 
-	tgt_value = getenv(dst->env_var_name);
+	tgt_value = tr2_sysenv_get(dst->sysenv_var);
 
 	if (!tgt_value || !strcmp(tgt_value, "") || !strcmp(tgt_value, "0") ||
 	    !strcasecmp(tgt_value, "false")) {
@@ -246,7 +247,8 @@ void tr2_dst_write_line(struct tr2_dst *dst, struct strbuf *buf_line)
 		return;
 
 	if (tr2_dst_want_warning())
-		warning("unable to write trace to '%s': %s", dst->env_var_name,
+		warning("unable to write trace to '%s': %s",
+			tr2_sysenv_display_name(dst->sysenv_var),
 			strerror(errno));
 	tr2_dst_trace_disable(dst);
 }
diff --git a/trace2/tr2_dst.h b/trace2/tr2_dst.h
index 9a64f05b02..3adf3bac13 100644
--- a/trace2/tr2_dst.h
+++ b/trace2/tr2_dst.h
@@ -2,9 +2,10 @@
 #define TR2_DST_H
 
 struct strbuf;
+#include "trace2/tr2_sysenv.h"
 
 struct tr2_dst {
-	const char *const env_var_name;
+	enum tr2_sysenv_variable sysenv_var;
 	int fd;
 	unsigned int initialized : 1;
 	unsigned int need_close : 1;
diff --git a/trace2/tr2_sysenv.c b/trace2/tr2_sysenv.c
new file mode 100644
index 0000000000..9025b86303
--- /dev/null
+++ b/trace2/tr2_sysenv.c
@@ -0,0 +1,127 @@
+#include "cache.h"
+#include "config.h"
+#include "dir.h"
+#include "tr2_sysenv.h"
+
+/*
+ * Each entry represents a trace2 setting.
+ * See Documentation/technical/api-trace2.txt
+ */
+struct tr2_sysenv_entry {
+	const char *env_var_name;
+	const char *git_config_name;
+
+	char *value;
+	unsigned int getenv_called : 1;
+};
+
+/*
+ * This table must match "enum tr2_sysenv_variable" in tr2_sysenv.h.
+ *
+ * The strings in this table are constant and must match the published
+ * config and environment variable names as described in the documentation.
+ *
+ * We do not define entries for the GIT_TR2_PARENT_* environment
+ * variables because they are transient and used to pass information
+ * from parent to child git processes, rather than settings.
+ */
+/* clang-format off */
+static struct tr2_sysenv_entry tr2_sysenv_settings[] = {
+	[TR2_SYSENV_CFG_PARAM]     = { "GIT_TR2_CONFIG_PARAMS",
+				       "trace2.configparams" },
+
+	[TR2_SYSENV_DST_DEBUG]     = { "GIT_TR2_DST_DEBUG",
+				       "trace2.destinationdebug" },
+
+	[TR2_SYSENV_NORMAL]        = { "GIT_TR2",
+				       "trace2.normaltarget" },
+	[TR2_SYSENV_NORMAL_BRIEF]  = { "GIT_TR2_BRIEF",
+				       "trace2.normalbrief" },
+
+	[TR2_SYSENV_EVENT]         = { "GIT_TR2_EVENT",
+				       "trace2.eventtarget" },
+	[TR2_SYSENV_EVENT_BRIEF]   = { "GIT_TR2_EVENT_BRIEF",
+				       "trace2.eventbrief" },
+	[TR2_SYSENV_EVENT_NESTING] = { "GIT_TR2_EVENT_NESTING",
+				       "trace2.eventnesting" },
+
+	[TR2_SYSENV_PERF]          = { "GIT_TR2_PERF",
+				       "trace2.perftarget" },
+	[TR2_SYSENV_PERF_BRIEF]    = { "GIT_TR2_PERF_BRIEF",
+				       "trace2.perfbrief" },
+};
+/* clang-format on */
+
+static int tr2_sysenv_cb(const char *key, const char *value, void *d)
+{
+	int k;
+
+	if (!starts_with(key, "trace2."))
+		return 0;
+
+	for (k = 0; k < ARRAY_SIZE(tr2_sysenv_settings); k++) {
+		if (!strcmp(key, tr2_sysenv_settings[k].git_config_name)) {
+			free(tr2_sysenv_settings[k].value);
+			tr2_sysenv_settings[k].value = xstrdup(value);
+			return 0;
+		}
+	}
+
+	return 0;
+}
+
+/*
+ * Load Trace2 settings from the system config (usually "/etc/gitconfig"
+ * unless we were built with a runtime-prefix).  These are intended to
+ * define the default values for Trace2 as requested by the administrator.
+ *
+ * Then override with the Trace2 settings from the global config.
+ */
+void tr2_sysenv_load(void)
+{
+	if (ARRAY_SIZE(tr2_sysenv_settings) != TR2_SYSENV_MUST_BE_LAST)
+		BUG("tr2_sysenv_settings size is wrong");
+
+	read_very_early_config(tr2_sysenv_cb, NULL);
+}
+
+/*
+ * Return the value for the requested Trace2 setting from these sources:
+ * the system config, the global config, and the environment.
+ */
+const char *tr2_sysenv_get(enum tr2_sysenv_variable var)
+{
+	if (var >= TR2_SYSENV_MUST_BE_LAST)
+		BUG("tr2_sysenv_get invalid var '%d'", var);
+
+	if (!tr2_sysenv_settings[var].getenv_called) {
+		const char *v = getenv(tr2_sysenv_settings[var].env_var_name);
+		if (v && *v) {
+			free(tr2_sysenv_settings[var].value);
+			tr2_sysenv_settings[var].value = xstrdup(v);
+		}
+		tr2_sysenv_settings[var].getenv_called = 1;
+	}
+
+	return tr2_sysenv_settings[var].value;
+}
+
+/*
+ * Return a friendly name for this setting that is suitable for printing
+ * in an error messages.
+ */
+const char *tr2_sysenv_display_name(enum tr2_sysenv_variable var)
+{
+	if (var >= TR2_SYSENV_MUST_BE_LAST)
+		BUG("tr2_sysenv_get invalid var '%d'", var);
+
+	return tr2_sysenv_settings[var].env_var_name;
+}
+
+void tr2_sysenv_release(void)
+{
+	int k;
+
+	for (k = 0; k < ARRAY_SIZE(tr2_sysenv_settings); k++)
+		free(tr2_sysenv_settings[k].value);
+}
diff --git a/trace2/tr2_sysenv.h b/trace2/tr2_sysenv.h
new file mode 100644
index 0000000000..369b20bd87
--- /dev/null
+++ b/trace2/tr2_sysenv.h
@@ -0,0 +1,36 @@
+#ifndef TR2_SYSENV_H
+#define TR2_SYSENV_H
+
+/*
+ * The Trace2 settings that can be loaded from /etc/gitconfig
+ * and/or user environment variables.
+ *
+ * Note that this set does not contain any of the transient
+ * environment variables used to pass information from parent
+ * to child git processes, such "GIT_TR2_PARENT_SID".
+ */
+enum tr2_sysenv_variable {
+	TR2_SYSENV_CFG_PARAM = 0,
+
+	TR2_SYSENV_DST_DEBUG,
+
+	TR2_SYSENV_NORMAL,
+	TR2_SYSENV_NORMAL_BRIEF,
+
+	TR2_SYSENV_EVENT,
+	TR2_SYSENV_EVENT_BRIEF,
+	TR2_SYSENV_EVENT_NESTING,
+
+	TR2_SYSENV_PERF,
+	TR2_SYSENV_PERF_BRIEF,
+
+	TR2_SYSENV_MUST_BE_LAST
+};
+
+void tr2_sysenv_load(void);
+
+const char *tr2_sysenv_get(enum tr2_sysenv_variable);
+const char *tr2_sysenv_display_name(enum tr2_sysenv_variable var);
+void tr2_sysenv_release(void);
+
+#endif /* TR2_SYSENV_H */
diff --git a/trace2/tr2_tgt_event.c b/trace2/tr2_tgt_event.c
index 89a4d3ae9a..48d9193b2c 100644
--- a/trace2/tr2_tgt_event.c
+++ b/trace2/tr2_tgt_event.c
@@ -6,10 +6,11 @@
 #include "trace2/tr2_dst.h"
 #include "trace2/tr2_tbuf.h"
 #include "trace2/tr2_sid.h"
+#include "trace2/tr2_sysenv.h"
 #include "trace2/tr2_tgt.h"
 #include "trace2/tr2_tls.h"
 
-static struct tr2_dst tr2dst_event = { "GIT_TR2_EVENT", 0, 0, 0 };
+static struct tr2_dst tr2dst_event = { TR2_SYSENV_EVENT, 0, 0, 0 };
 
 /*
  * The version number of the JSON data generated by the EVENT target
@@ -28,37 +29,36 @@ static struct tr2_dst tr2dst_event = { "GIT_TR2_EVENT", 0, 0, 0 };
  * are primarily intended for the performance target during debugging.
  *
  * Some of the outer-most messages, however, may be of interest to the
- * event target.  Set this environment variable to a larger integer for
- * more detail in the event target.
+ * event target.  Use the TR2_SYSENV_EVENT_NESTING setting to increase
+ * region details in the event target.
  */
-#define TR2_ENVVAR_EVENT_NESTING "GIT_TR2_EVENT_NESTING"
-static int tr2env_event_nesting_wanted = 2;
+static int tr2env_event_max_nesting_levels = 2;
 
 /*
- * Set this environment variable to true to omit the <time>, <file>, and
+ * Use the TR2_SYSENV_EVENT_BRIEF to omit the <time>, <file>, and
  * <line> fields from most events.
  */
-#define TR2_ENVVAR_EVENT_BRIEF "GIT_TR2_EVENT_BRIEF"
-static int tr2env_event_brief;
+static int tr2env_event_be_brief;
 
 static int fn_init(void)
 {
 	int want = tr2_dst_trace_want(&tr2dst_event);
-	int want_nesting;
+	int max_nesting;
 	int want_brief;
-	char *nesting;
-	char *brief;
+	const char *nesting;
+	const char *brief;
 
 	if (!want)
 		return want;
 
-	nesting = getenv(TR2_ENVVAR_EVENT_NESTING);
-	if (nesting && ((want_nesting = atoi(nesting)) > 0))
-		tr2env_event_nesting_wanted = want_nesting;
+	nesting = tr2_sysenv_get(TR2_SYSENV_EVENT_NESTING);
+	if (nesting && *nesting && ((max_nesting = atoi(nesting)) > 0))
+		tr2env_event_max_nesting_levels = max_nesting;
 
-	brief = getenv(TR2_ENVVAR_EVENT_BRIEF);
-	if (brief && ((want_brief = atoi(brief)) > 0))
-		tr2env_event_brief = want_brief;
+	brief = tr2_sysenv_get(TR2_SYSENV_EVENT_BRIEF);
+	if (brief && *brief &&
+	    ((want_brief = git_parse_maybe_bool(brief)) != -1))
+		tr2env_event_be_brief = want_brief;
 
 	return want;
 }
@@ -92,13 +92,13 @@ static void event_fmt_prepare(const char *event_name, const char *file,
 	/*
 	 * In brief mode, only emit <time> on these 2 event types.
 	 */
-	if (!tr2env_event_brief || !strcmp(event_name, "version") ||
+	if (!tr2env_event_be_brief || !strcmp(event_name, "version") ||
 	    !strcmp(event_name, "atexit")) {
 		tr2_tbuf_utc_time(&tb_now);
 		jw_object_string(jw, "time", tb_now.buf);
 	}
 
-	if (!tr2env_event_brief && file && *file) {
+	if (!tr2env_event_be_brief && file && *file) {
 		jw_object_string(jw, "file", file);
 		jw_object_intmax(jw, "line", line);
 	}
@@ -459,7 +459,7 @@ static void fn_region_enter_printf_va_fl(const char *file, int line,
 {
 	const char *event_name = "region_enter";
 	struct tr2tls_thread_ctx *ctx = tr2tls_get_self();
-	if (ctx->nr_open_regions <= tr2env_event_nesting_wanted) {
+	if (ctx->nr_open_regions <= tr2env_event_max_nesting_levels) {
 		struct json_writer jw = JSON_WRITER_INIT;
 
 		jw_object_begin(&jw, 0);
@@ -484,7 +484,7 @@ static void fn_region_leave_printf_va_fl(
 {
 	const char *event_name = "region_leave";
 	struct tr2tls_thread_ctx *ctx = tr2tls_get_self();
-	if (ctx->nr_open_regions <= tr2env_event_nesting_wanted) {
+	if (ctx->nr_open_regions <= tr2env_event_max_nesting_levels) {
 		struct json_writer jw = JSON_WRITER_INIT;
 		double t_rel = (double)us_elapsed_region / 1000000.0;
 
@@ -511,7 +511,7 @@ static void fn_data_fl(const char *file, int line, uint64_t us_elapsed_absolute,
 {
 	const char *event_name = "data";
 	struct tr2tls_thread_ctx *ctx = tr2tls_get_self();
-	if (ctx->nr_open_regions <= tr2env_event_nesting_wanted) {
+	if (ctx->nr_open_regions <= tr2env_event_max_nesting_levels) {
 		struct json_writer jw = JSON_WRITER_INIT;
 		double t_abs = (double)us_elapsed_absolute / 1000000.0;
 		double t_rel = (double)us_elapsed_region / 1000000.0;
@@ -539,7 +539,7 @@ static void fn_data_json_fl(const char *file, int line,
 {
 	const char *event_name = "data_json";
 	struct tr2tls_thread_ctx *ctx = tr2tls_get_self();
-	if (ctx->nr_open_regions <= tr2env_event_nesting_wanted) {
+	if (ctx->nr_open_regions <= tr2env_event_max_nesting_levels) {
 		struct json_writer jw = JSON_WRITER_INIT;
 		double t_abs = (double)us_elapsed_absolute / 1000000.0;
 		double t_rel = (double)us_elapsed_region / 1000000.0;
diff --git a/trace2/tr2_tgt_normal.c b/trace2/tr2_tgt_normal.c
index 57f3e18f5b..1ce6f97863 100644
--- a/trace2/tr2_tgt_normal.c
+++ b/trace2/tr2_tgt_normal.c
@@ -4,20 +4,20 @@
 #include "quote.h"
 #include "version.h"
 #include "trace2/tr2_dst.h"
+#include "trace2/tr2_sysenv.h"
 #include "trace2/tr2_tbuf.h"
 #include "trace2/tr2_tgt.h"
 #include "trace2/tr2_tls.h"
 
-static struct tr2_dst tr2dst_normal = { "GIT_TR2", 0, 0, 0 };
+static struct tr2_dst tr2dst_normal = { TR2_SYSENV_NORMAL, 0, 0, 0 };
 
 /*
- * Set this environment variable to true to omit the "<time> <file>:<line>"
+ * Use the TR2_SYSENV_NORMAL_BRIEF setting to omit the "<time> <file>:<line>"
  * fields from each line written to the builtin normal target.
  *
  * Unit tests may want to use this to help with testing.
  */
-#define TR2_ENVVAR_NORMAL_BRIEF "GIT_TR2_BRIEF"
-static int tr2env_normal_brief;
+static int tr2env_normal_be_brief;
 
 #define TR2FMT_NORMAL_FL_WIDTH (50)
 
@@ -25,15 +25,15 @@ static int fn_init(void)
 {
 	int want = tr2_dst_trace_want(&tr2dst_normal);
 	int want_brief;
-	char *brief;
+	const char *brief;
 
 	if (!want)
 		return want;
 
-	brief = getenv(TR2_ENVVAR_NORMAL_BRIEF);
+	brief = tr2_sysenv_get(TR2_SYSENV_NORMAL_BRIEF);
 	if (brief && *brief &&
 	    ((want_brief = git_parse_maybe_bool(brief)) != -1))
-		tr2env_normal_brief = want_brief;
+		tr2env_normal_be_brief = want_brief;
 
 	return want;
 }
@@ -47,7 +47,7 @@ static void normal_fmt_prepare(const char *file, int line, struct strbuf *buf)
 {
 	strbuf_setlen(buf, 0);
 
-	if (!tr2env_normal_brief) {
+	if (!tr2env_normal_be_brief) {
 		struct tr2_tbuf tb_now;
 
 		tr2_tbuf_local_time(&tb_now);
diff --git a/trace2/tr2_tgt_perf.c b/trace2/tr2_tgt_perf.c
index 9c3b4d8a0f..328d2234bd 100644
--- a/trace2/tr2_tgt_perf.c
+++ b/trace2/tr2_tgt_perf.c
@@ -6,20 +6,20 @@
 #include "json-writer.h"
 #include "trace2/tr2_dst.h"
 #include "trace2/tr2_sid.h"
+#include "trace2/tr2_sysenv.h"
 #include "trace2/tr2_tbuf.h"
 #include "trace2/tr2_tgt.h"
 #include "trace2/tr2_tls.h"
 
-static struct tr2_dst tr2dst_perf = { "GIT_TR2_PERF", 0, 0, 0 };
+static struct tr2_dst tr2dst_perf = { TR2_SYSENV_PERF, 0, 0, 0 };
 
 /*
- * Set this environment variable to true to omit the "<time> <file>:<line>"
+ * Use TR2_SYSENV_PERF_BRIEF to omit the "<time> <file>:<line>"
  * fields from each line written to the builtin performance target.
  *
  * Unit tests may want to use this to help with testing.
  */
-#define TR2_ENVVAR_PERF_BRIEF "GIT_TR2_PERF_BRIEF"
-static int tr2env_perf_brief;
+static int tr2env_perf_be_brief;
 
 #define TR2FMT_PERF_FL_WIDTH (50)
 #define TR2FMT_PERF_MAX_EVENT_NAME (12)
@@ -36,17 +36,17 @@ static int fn_init(void)
 {
 	int want = tr2_dst_trace_want(&tr2dst_perf);
 	int want_brief;
-	char *brief;
+	const char *brief;
 
 	if (!want)
 		return want;
 
 	strbuf_addchars(&dots, '.', TR2_DOTS_BUFFER_SIZE);
 
-	brief = getenv(TR2_ENVVAR_PERF_BRIEF);
+	brief = tr2_sysenv_get(TR2_SYSENV_PERF_BRIEF);
 	if (brief && *brief &&
 	    ((want_brief = git_parse_maybe_bool(brief)) != -1))
-		tr2env_perf_brief = want_brief;
+		tr2env_perf_be_brief = want_brief;
 
 	return want;
 }
@@ -77,7 +77,7 @@ static void perf_fmt_prepare(const char *event_name,
 
 	strbuf_setlen(buf, 0);
 
-	if (!tr2env_perf_brief) {
+	if (!tr2env_perf_be_brief) {
 		struct tr2_tbuf tb_now;
 
 		tr2_tbuf_local_time(&tb_now);
-- 
gitgitgadget


^ permalink raw reply	[flat|nested] 68+ messages in thread

* [PATCH v4 07/10] trace2: report peak memory usage of the process
  2019-04-15 20:39     ` [PATCH v4 " Jeff Hostetler via GitGitGadget
                         ` (6 preceding siblings ...)
  2019-04-15 20:39       ` [PATCH v4 08/10] trace2: clarify UTC datetime formatting Jeff Hostetler via GitGitGadget
@ 2019-04-15 20:39       ` Jeff Hostetler via GitGitGadget
  2019-04-15 20:39       ` [PATCH v4 09/10] trace2: make SIDs more unique Jeff Hostetler via GitGitGadget
                         ` (2 subsequent siblings)
  10 siblings, 0 replies; 68+ messages in thread
From: Jeff Hostetler via GitGitGadget @ 2019-04-15 20:39 UTC (permalink / raw)
  To: git
  Cc: gitster, peff, jrnieder, steadmon, avarab, Junio C Hamano,
	Jeff Hostetler

From: Jeff Hostetler <jeffhost@microsoft.com>

Teach Windows version of git to report peak memory usage
during exit() processing.

Signed-off-by: Jeff Hostetler <jeffhost@microsoft.com>
---
 common-main.c                            |  2 +-
 compat/win32/trace2_win32_process_info.c | 50 ++++++++++++++++++++++--
 trace2.c                                 |  2 +
 trace2.h                                 | 14 +++++--
 4 files changed, 60 insertions(+), 8 deletions(-)

diff --git a/common-main.c b/common-main.c
index 299ca62a72..582a7b1886 100644
--- a/common-main.c
+++ b/common-main.c
@@ -41,7 +41,7 @@ int main(int argc, const char **argv)
 
 	trace2_initialize();
 	trace2_cmd_start(argv);
-	trace2_collect_process_info();
+	trace2_collect_process_info(TRACE2_PROCESS_INFO_STARTUP);
 
 	git_setup_gettext();
 
diff --git a/compat/win32/trace2_win32_process_info.c b/compat/win32/trace2_win32_process_info.c
index 52bd62034b..8ccbd1c2c6 100644
--- a/compat/win32/trace2_win32_process_info.c
+++ b/compat/win32/trace2_win32_process_info.c
@@ -1,5 +1,6 @@
 #include "../../cache.h"
 #include "../../json-writer.h"
+#include "lazyload.h"
 #include <Psapi.h>
 #include <tlHelp32.h>
 
@@ -137,11 +138,54 @@ static void get_is_being_debugged(void)
 				   "windows/debugger_present", 1);
 }
 
-void trace2_collect_process_info(void)
+/*
+ * Emit JSON data with the peak memory usage of the current process.
+ */
+static void get_peak_memory_info(void)
+{
+	DECLARE_PROC_ADDR(psapi.dll, BOOL, GetProcessMemoryInfo, HANDLE,
+			  PPROCESS_MEMORY_COUNTERS, DWORD);
+
+	if (INIT_PROC_ADDR(GetProcessMemoryInfo)) {
+		PROCESS_MEMORY_COUNTERS pmc;
+
+		if (GetProcessMemoryInfo(GetCurrentProcess(), &pmc,
+					 sizeof(pmc))) {
+			struct json_writer jw = JSON_WRITER_INIT;
+
+			jw_object_begin(&jw, 0);
+
+#define KV(kv) #kv, (intmax_t)pmc.kv
+
+			jw_object_intmax(&jw, KV(PageFaultCount));
+			jw_object_intmax(&jw, KV(PeakWorkingSetSize));
+			jw_object_intmax(&jw, KV(PeakPagefileUsage));
+
+			jw_end(&jw);
+
+			trace2_data_json("process", the_repository,
+					 "windows/memory", &jw);
+			jw_release(&jw);
+		}
+	}
+}
+
+void trace2_collect_process_info(enum trace2_process_info_reason reason)
 {
 	if (!trace2_is_enabled())
 		return;
 
-	get_is_being_debugged();
-	get_ancestry();
+	switch (reason) {
+	case TRACE2_PROCESS_INFO_STARTUP:
+		get_is_being_debugged();
+		get_ancestry();
+		return;
+
+	case TRACE2_PROCESS_INFO_EXIT:
+		get_peak_memory_info();
+		return;
+
+	default:
+		BUG("trace2_collect_process_info: unknown reason '%d'", reason);
+	}
 }
diff --git a/trace2.c b/trace2.c
index 490b3f071e..6baa65cdf9 100644
--- a/trace2.c
+++ b/trace2.c
@@ -213,6 +213,8 @@ int trace2_cmd_exit_fl(const char *file, int line, int code)
 	if (!trace2_enabled)
 		return code;
 
+	trace2_collect_process_info(TRACE2_PROCESS_INFO_EXIT);
+
 	tr2main_exit_code = code;
 
 	us_now = getnanotime() / 1000;
diff --git a/trace2.h b/trace2.h
index 894bfca7e0..888531eb08 100644
--- a/trace2.h
+++ b/trace2.h
@@ -391,13 +391,19 @@ void trace2_printf(const char *fmt, ...);
  * Optional platform-specific code to dump information about the
  * current and any parent process(es).  This is intended to allow
  * post-processors to know who spawned this git instance and anything
- * else the platform may be able to tell us about the current process.
+ * else that the platform may be able to tell us about the current process.
  */
+
+enum trace2_process_info_reason {
+	TRACE2_PROCESS_INFO_STARTUP,
+	TRACE2_PROCESS_INFO_EXIT,
+};
+
 #if defined(GIT_WINDOWS_NATIVE)
-void trace2_collect_process_info(void);
+void trace2_collect_process_info(enum trace2_process_info_reason reason);
 #else
-#define trace2_collect_process_info() \
-	do {                          \
+#define trace2_collect_process_info(reason) \
+	do {                                \
 	} while (0)
 #endif
 
-- 
gitgitgadget


^ permalink raw reply	[flat|nested] 68+ messages in thread

* [PATCH v4 08/10] trace2: clarify UTC datetime formatting
  2019-04-15 20:39     ` [PATCH v4 " Jeff Hostetler via GitGitGadget
                         ` (5 preceding siblings ...)
  2019-04-15 20:39       ` [PATCH v4 06/10] trace2: use system/global config for default trace2 settings Jeff Hostetler via GitGitGadget
@ 2019-04-15 20:39       ` Jeff Hostetler via GitGitGadget
  2019-04-15 20:39       ` [PATCH v4 07/10] trace2: report peak memory usage of the process Jeff Hostetler via GitGitGadget
                         ` (3 subsequent siblings)
  10 siblings, 0 replies; 68+ messages in thread
From: Jeff Hostetler via GitGitGadget @ 2019-04-15 20:39 UTC (permalink / raw)
  To: git
  Cc: gitster, peff, jrnieder, steadmon, avarab, Junio C Hamano,
	Jeff Hostetler

From: Jeff Hostetler <jeffhost@microsoft.com>

Update tr2_tbuf_utc_datetime to generate extended UTC format.
Update tr2_tgt_event target to use extended format in 'time' columns.

Signed-off-by: Jeff Hostetler <jeffhost@microsoft.com>
---
 Documentation/technical/api-trace2.txt | 12 ++++++------
 trace2/tr2_tbuf.c                      |  4 ++--
 trace2/tr2_tbuf.h                      |  4 ++--
 trace2/tr2_tgt_event.c                 |  2 +-
 4 files changed, 11 insertions(+), 11 deletions(-)

diff --git a/Documentation/technical/api-trace2.txt b/Documentation/technical/api-trace2.txt
index baaa1153bb..cdc00bcc5d 100644
--- a/Documentation/technical/api-trace2.txt
+++ b/Documentation/technical/api-trace2.txt
@@ -78,11 +78,11 @@ git version 2.20.1.155.g426c96fcdb
 +
 ------------
 $ cat ~/log.event
-{"event":"version","sid":"1547659722619736-11614","thread":"main","time":"2019-01-16 17:28:42.620713","file":"common-main.c","line":38,"evt":"1","exe":"2.20.1.155.g426c96fcdb"}
-{"event":"start","sid":"1547659722619736-11614","thread":"main","time":"2019-01-16 17:28:42.621027","file":"common-main.c","line":39,"t_abs":0.001173,"argv":["git","version"]}
-{"event":"cmd_name","sid":"1547659722619736-11614","thread":"main","time":"2019-01-16 17:28:42.621122","file":"git.c","line":432,"name":"version","hierarchy":"version"}
-{"event":"exit","sid":"1547659722619736-11614","thread":"main","time":"2019-01-16 17:28:42.621236","file":"git.c","line":662,"t_abs":0.001227,"code":0}
-{"event":"atexit","sid":"1547659722619736-11614","thread":"main","time":"2019-01-16 17:28:42.621268","file":"trace2/tr2_tgt_event.c","line":163,"t_abs":0.001265,"code":0}
+{"event":"version","sid":"1547659722619736-11614","thread":"main","time":"2019-01-16T17:28:42.620713Z","file":"common-main.c","line":38,"evt":"1","exe":"2.20.1.155.g426c96fcdb"}
+{"event":"start","sid":"1547659722619736-11614","thread":"main","time":"2019-01-16T17:28:42.621027Z","file":"common-main.c","line":39,"t_abs":0.001173,"argv":["git","version"]}
+{"event":"cmd_name","sid":"1547659722619736-11614","thread":"main","time":"2019-01-16T17:28:42.621122Z","file":"git.c","line":432,"name":"version","hierarchy":"version"}
+{"event":"exit","sid":"1547659722619736-11614","thread":"main","time":"2019-01-16T17:28:42.621236Z","file":"git.c","line":662,"t_abs":0.001227,"code":0}
+{"event":"atexit","sid":"1547659722619736-11614","thread":"main","time":"2019-01-16T17:28:42.621268Z","file":"trace2/tr2_tgt_event.c","line":163,"t_abs":0.001265,"code":0}
 ------------
 
 == Enabling a Target
@@ -542,7 +542,7 @@ The following key/value pairs are common to all events:
 	"event":"version",
 	"sid":"1547659722619736-11614",
 	"thread":"main",
-	"time":"2019-01-16 17:28:42.620713",
+	"time":"2019-01-16T17:28:42.620713Z",
 	"file":"common-main.c",
 	"line":38,
 	...
diff --git a/trace2/tr2_tbuf.c b/trace2/tr2_tbuf.c
index 0844910423..eb1b240d8a 100644
--- a/trace2/tr2_tbuf.c
+++ b/trace2/tr2_tbuf.c
@@ -15,7 +15,7 @@ void tr2_tbuf_local_time(struct tr2_tbuf *tb)
 		  tm.tm_min, tm.tm_sec, (long)tv.tv_usec);
 }
 
-void tr2_tbuf_utc_time(struct tr2_tbuf *tb)
+void tr2_tbuf_utc_datetime_extended(struct tr2_tbuf *tb)
 {
 	struct timeval tv;
 	struct tm tm;
@@ -26,7 +26,7 @@ void tr2_tbuf_utc_time(struct tr2_tbuf *tb)
 	gmtime_r(&secs, &tm);
 
 	xsnprintf(tb->buf, sizeof(tb->buf),
-		  "%4d-%02d-%02d %02d:%02d:%02d.%06ld", tm.tm_year + 1900,
+		  "%4d-%02d-%02dT%02d:%02d:%02d.%06ldZ", tm.tm_year + 1900,
 		  tm.tm_mon + 1, tm.tm_mday, tm.tm_hour, tm.tm_min, tm.tm_sec,
 		  (long)tv.tv_usec);
 }
diff --git a/trace2/tr2_tbuf.h b/trace2/tr2_tbuf.h
index 9cdefa3957..2a1d173ff2 100644
--- a/trace2/tr2_tbuf.h
+++ b/trace2/tr2_tbuf.h
@@ -16,8 +16,8 @@ struct tr2_tbuf {
 void tr2_tbuf_local_time(struct tr2_tbuf *tb);
 
 /*
- * Fill buffer with formatted UTC time string.
+ * Fill buffer with formatted UTC datatime string.
  */
-void tr2_tbuf_utc_time(struct tr2_tbuf *tb);
+void tr2_tbuf_utc_datetime_extended(struct tr2_tbuf *tb);
 
 #endif /* TR2_TBUF_H */
diff --git a/trace2/tr2_tgt_event.c b/trace2/tr2_tgt_event.c
index 48d9193b2c..2c97cf54be 100644
--- a/trace2/tr2_tgt_event.c
+++ b/trace2/tr2_tgt_event.c
@@ -94,7 +94,7 @@ static void event_fmt_prepare(const char *event_name, const char *file,
 	 */
 	if (!tr2env_event_be_brief || !strcmp(event_name, "version") ||
 	    !strcmp(event_name, "atexit")) {
-		tr2_tbuf_utc_time(&tb_now);
+		tr2_tbuf_utc_datetime_extended(&tb_now);
 		jw_object_string(jw, "time", tb_now.buf);
 	}
 
-- 
gitgitgadget


^ permalink raw reply	[flat|nested] 68+ messages in thread

* [PATCH v4 09/10] trace2: make SIDs more unique
  2019-04-15 20:39     ` [PATCH v4 " Jeff Hostetler via GitGitGadget
                         ` (7 preceding siblings ...)
  2019-04-15 20:39       ` [PATCH v4 07/10] trace2: report peak memory usage of the process Jeff Hostetler via GitGitGadget
@ 2019-04-15 20:39       ` Jeff Hostetler via GitGitGadget
  2019-04-15 20:39       ` [PATCH v4 10/10] trace2: update docs to describe system/global config settings Jeff Hostetler via GitGitGadget
  2019-04-29 20:14       ` [PATCH v5 00/11] trace2: load trace2 settings from system config Jeff Hostetler via GitGitGadget
  10 siblings, 0 replies; 68+ messages in thread
From: Jeff Hostetler via GitGitGadget @ 2019-04-15 20:39 UTC (permalink / raw)
  To: git
  Cc: gitster, peff, jrnieder, steadmon, avarab, Junio C Hamano,
	Jeff Hostetler

From: Jeff Hostetler <jeffhost@microsoft.com>

Update SID component construction to use the current UTC datetime
and a portion of the SHA1 of the hostname.

Use an simplified date/time format to make it easier to use the
SID component as a logfile filename.

Signed-off-by: Jeff Hostetler <jeffhost@microsoft.com>
---
 Documentation/technical/api-trace2.txt | 16 ++++----
 trace2/tr2_sid.c                       | 53 ++++++++++++++++++++++++--
 trace2/tr2_tbuf.c                      | 15 ++++++++
 trace2/tr2_tbuf.h                      |  1 +
 4 files changed, 73 insertions(+), 12 deletions(-)

diff --git a/Documentation/technical/api-trace2.txt b/Documentation/technical/api-trace2.txt
index cdc00bcc5d..43adbf00eb 100644
--- a/Documentation/technical/api-trace2.txt
+++ b/Documentation/technical/api-trace2.txt
@@ -78,11 +78,11 @@ git version 2.20.1.155.g426c96fcdb
 +
 ------------
 $ cat ~/log.event
-{"event":"version","sid":"1547659722619736-11614","thread":"main","time":"2019-01-16T17:28:42.620713Z","file":"common-main.c","line":38,"evt":"1","exe":"2.20.1.155.g426c96fcdb"}
-{"event":"start","sid":"1547659722619736-11614","thread":"main","time":"2019-01-16T17:28:42.621027Z","file":"common-main.c","line":39,"t_abs":0.001173,"argv":["git","version"]}
-{"event":"cmd_name","sid":"1547659722619736-11614","thread":"main","time":"2019-01-16T17:28:42.621122Z","file":"git.c","line":432,"name":"version","hierarchy":"version"}
-{"event":"exit","sid":"1547659722619736-11614","thread":"main","time":"2019-01-16T17:28:42.621236Z","file":"git.c","line":662,"t_abs":0.001227,"code":0}
-{"event":"atexit","sid":"1547659722619736-11614","thread":"main","time":"2019-01-16T17:28:42.621268Z","file":"trace2/tr2_tgt_event.c","line":163,"t_abs":0.001265,"code":0}
+{"event":"version","sid":"sid":"20190408T191610.507018Z-H9b68c35f-P028492","thread":"main","time":"2019-01-16T17:28:42.620713Z","file":"common-main.c","line":38,"evt":"1","exe":"2.20.1.155.g426c96fcdb"}
+{"event":"start","sid":"20190408T191610.507018Z-H9b68c35f-P028492","thread":"main","time":"2019-01-16T17:28:42.621027Z","file":"common-main.c","line":39,"t_abs":0.001173,"argv":["git","version"]}
+{"event":"cmd_name","sid":"20190408T191610.507018Z-H9b68c35f-P028492","thread":"main","time":"2019-01-16T17:28:42.621122Z","file":"git.c","line":432,"name":"version","hierarchy":"version"}
+{"event":"exit","sid":"20190408T191610.507018Z-H9b68c35f-P028492","thread":"main","time":"2019-01-16T17:28:42.621236Z","file":"git.c","line":662,"t_abs":0.001227,"code":0}
+{"event":"atexit","sid":"20190408T191610.507018Z-H9b68c35f-P028492","thread":"main","time":"2019-01-16T17:28:42.621268Z","file":"trace2/tr2_tgt_event.c","line":163,"t_abs":0.001265,"code":0}
 ------------
 
 == Enabling a Target
@@ -540,11 +540,11 @@ The following key/value pairs are common to all events:
 ------------
 {
 	"event":"version",
-	"sid":"1547659722619736-11614",
+	"sid":"20190408T191827.272759Z-H9b68c35f-P011764",
 	"thread":"main",
-	"time":"2019-01-16T17:28:42.620713Z",
+	"time":"2019-04-08T19:18:27.282761Z",
 	"file":"common-main.c",
-	"line":38,
+	"line":42,
 	...
 }
 ------------
diff --git a/trace2/tr2_sid.c b/trace2/tr2_sid.c
index 984524a43c..5047095478 100644
--- a/trace2/tr2_sid.c
+++ b/trace2/tr2_sid.c
@@ -1,4 +1,5 @@
 #include "cache.h"
+#include "trace2/tr2_tbuf.h"
 #include "trace2/tr2_sid.h"
 
 #define TR2_ENVVAR_PARENT_SID "GIT_TR2_PARENT_SID"
@@ -6,6 +7,53 @@
 static struct strbuf tr2sid_buf = STRBUF_INIT;
 static int tr2sid_nr_git_parents;
 
+/*
+ * Compute the final component of the SID representing the current process.
+ * This should uniquely identify the process and be a valid filename (to
+ * allow writing trace2 data to per-process files).  It should also be fixed
+ * length for possible use as a database key.
+ *
+ * "<yyyymmdd>T<hhmmss>.<fraction>Z-<host>-<process>"
+ *
+ * where <host> is a 9 character string:
+ *    "H<first_8_chars_of_sha1_of_hostname>"
+ *    "Localhost" when no hostname.
+ *
+ * where <process> is a 9 character string containing the least signifcant
+ * 32 bits in the process-id.
+ *    "P<pid>"
+ * (This is an abribrary choice.  On most systems pid_t is a 32 bit value,
+ * so limit doesn't matter.  On larger systems, a truncated value is fine
+ * for our purposes here.)
+ */
+static void tr2_sid_append_my_sid_component(void)
+{
+	const struct git_hash_algo *algo = &hash_algos[GIT_HASH_SHA1];
+	struct tr2_tbuf tb_now;
+	git_hash_ctx ctx;
+	pid_t pid = getpid();
+	unsigned char hash[GIT_MAX_RAWSZ + 1];
+	char hex[GIT_MAX_HEXSZ + 1];
+	char hostname[HOST_NAME_MAX + 1];
+
+	tr2_tbuf_utc_datetime(&tb_now);
+	strbuf_addstr(&tr2sid_buf, tb_now.buf);
+
+	strbuf_addch(&tr2sid_buf, '-');
+	if (xgethostname(hostname, sizeof(hostname)))
+		strbuf_add(&tr2sid_buf, "Localhost", 9);
+	else {
+		algo->init_fn(&ctx);
+		algo->update_fn(&ctx, hostname, strlen(hostname));
+		algo->final_fn(hash, &ctx);
+		hash_to_hex_algop_r(hex, hash, algo);
+		strbuf_addch(&tr2sid_buf, 'H');
+		strbuf_add(&tr2sid_buf, hex, 8);
+	}
+
+	strbuf_addf(&tr2sid_buf, "-P%08"PRIx32, (uint32_t)pid);
+}
+
 /*
  * Compute a "unique" session id (SID) for the current process.  This allows
  * all events from this process to have a single label (much like a PID).
@@ -20,7 +68,6 @@ static int tr2sid_nr_git_parents;
  */
 static void tr2_sid_compute(void)
 {
-	uint64_t us_now;
 	const char *parent_sid;
 
 	if (tr2sid_buf.len)
@@ -38,9 +85,7 @@ static void tr2_sid_compute(void)
 		tr2sid_nr_git_parents++;
 	}
 
-	us_now = getnanotime() / 1000;
-	strbuf_addf(&tr2sid_buf, "%" PRIuMAX "-%" PRIdMAX, (uintmax_t)us_now,
-		    (intmax_t)getpid());
+	tr2_sid_append_my_sid_component();
 
 	setenv(TR2_ENVVAR_PARENT_SID, tr2sid_buf.buf, 1);
 }
diff --git a/trace2/tr2_tbuf.c b/trace2/tr2_tbuf.c
index eb1b240d8a..2498482d9a 100644
--- a/trace2/tr2_tbuf.c
+++ b/trace2/tr2_tbuf.c
@@ -30,3 +30,18 @@ void tr2_tbuf_utc_datetime_extended(struct tr2_tbuf *tb)
 		  tm.tm_mon + 1, tm.tm_mday, tm.tm_hour, tm.tm_min, tm.tm_sec,
 		  (long)tv.tv_usec);
 }
+
+void tr2_tbuf_utc_datetime(struct tr2_tbuf *tb)
+{
+	struct timeval tv;
+	struct tm tm;
+	time_t secs;
+
+	gettimeofday(&tv, NULL);
+	secs = tv.tv_sec;
+	gmtime_r(&secs, &tm);
+
+	xsnprintf(tb->buf, sizeof(tb->buf), "%4d%02d%02dT%02d%02d%02d.%06ldZ",
+		  tm.tm_year + 1900, tm.tm_mon + 1, tm.tm_mday, tm.tm_hour,
+		  tm.tm_min, tm.tm_sec, (long)tv.tv_usec);
+}
diff --git a/trace2/tr2_tbuf.h b/trace2/tr2_tbuf.h
index 2a1d173ff2..fa853d8f42 100644
--- a/trace2/tr2_tbuf.h
+++ b/trace2/tr2_tbuf.h
@@ -19,5 +19,6 @@ void tr2_tbuf_local_time(struct tr2_tbuf *tb);
  * Fill buffer with formatted UTC datatime string.
  */
 void tr2_tbuf_utc_datetime_extended(struct tr2_tbuf *tb);
+void tr2_tbuf_utc_datetime(struct tr2_tbuf *tb);
 
 #endif /* TR2_TBUF_H */
-- 
gitgitgadget


^ permalink raw reply	[flat|nested] 68+ messages in thread

* [PATCH v4 10/10] trace2: update docs to describe system/global config settings
  2019-04-15 20:39     ` [PATCH v4 " Jeff Hostetler via GitGitGadget
                         ` (8 preceding siblings ...)
  2019-04-15 20:39       ` [PATCH v4 09/10] trace2: make SIDs more unique Jeff Hostetler via GitGitGadget
@ 2019-04-15 20:39       ` Jeff Hostetler via GitGitGadget
  2019-04-29 20:14       ` [PATCH v5 00/11] trace2: load trace2 settings from system config Jeff Hostetler via GitGitGadget
  10 siblings, 0 replies; 68+ messages in thread
From: Jeff Hostetler via GitGitGadget @ 2019-04-15 20:39 UTC (permalink / raw)
  To: git
  Cc: gitster, peff, jrnieder, steadmon, avarab, Junio C Hamano,
	Jeff Hostetler

From: Jeff Hostetler <jeffhost@microsoft.com>

Signed-off-by: Jeff Hostetler <jeffhost@microsoft.com>
---
 Documentation/config.txt               |   2 +
 Documentation/config/trace2.txt        |  56 +++++++++
 Documentation/technical/api-trace2.txt | 151 ++++++++++++++-----------
 Documentation/trace2-target-values.txt |  10 ++
 4 files changed, 152 insertions(+), 67 deletions(-)
 create mode 100644 Documentation/config/trace2.txt
 create mode 100644 Documentation/trace2-target-values.txt

diff --git a/Documentation/config.txt b/Documentation/config.txt
index d87846faa6..7e2a6f61f5 100644
--- a/Documentation/config.txt
+++ b/Documentation/config.txt
@@ -422,6 +422,8 @@ include::config/submodule.txt[]
 
 include::config/tag.txt[]
 
+include::config/trace2.txt[]
+
 include::config/transfer.txt[]
 
 include::config/uploadarchive.txt[]
diff --git a/Documentation/config/trace2.txt b/Documentation/config/trace2.txt
new file mode 100644
index 0000000000..a5f409c1c1
--- /dev/null
+++ b/Documentation/config/trace2.txt
@@ -0,0 +1,56 @@
+Trace2 config settings are only read from the system and global
+config files; repository local and worktree config files and `-c`
+command line arguments are not respected.
+
+trace2.normalTarget::
+	This variable controls the normal target destination.
+	It may be overridden by the `GIT_TR2` environment variable.
+	The following table shows possible values.
+
+trace2.perfTarget::
+	This variable controls the performance target destination.
+	It may be overridden by the `GIT_TR2_PERF` environment variable.
+	The following table shows possible values.
+
+trace2.eventTarget::
+	This variable controls the event target destination.
+	It may be overridden by the `GIT_TR2_EVENT` environment variable.
+	The following table shows possible values.
++
+include::../trace2-target-values.txt[]
+
+trace2.normalBrief::
+	Boolean.  When true `time`, `filename`, and `line` fields are
+	omitted from normal output.  May be overridden by the
+	`GIT_TR2_BRIEF` environment variable.  Defaults to false.
+
+trace2.perfBrief::
+	Boolean.  When true `time`, `filename`, and `line` fields are
+	omitted from PERF output.  May be overridden by the
+	`GIT_TR2_PERF_BRIEF` environment variable.  Defaults to false.
+
+trace2.eventBrief::
+	Boolean.  When true `time`, `filename`, and `line` fields are
+	omitted from event output.  May be overridden by the
+	`GIT_TR2_EVENT_BRIEF` environment variable.  Defaults to false.
+
+trace2.eventNesting::
+	Integer.  Specifies desired depth of nested regions in the
+	event output.  Regions deeper than this value will be
+	omitted.  May be overridden by the `GIT_TR2_EVENT_NESTING`
+	environment variable.  Defaults to 2.
+
+trace2.configParams::
+	A comma-separated list of patterns of "important" config
+	settings that should be recorded in the trace2 output.
+	For example, `core.*,remote.*.url` would cause the trace2
+	output to contain events listing each configured remote.
+	May be overridden by the `GIT_TR2_CONFIG_PARAMS` environment
+	variable.  Unset by default.
+
+trace2.destinationDebug::
+	Boolean.  When true Git will print error messages when a
+	trace target destination cannot be opened for writing.
+	By default, these errors are suppressed and tracing is
+	silently disabled.  May be overridden by the
+	`GIT_TR2_DST_DEBUG` environment variable.
diff --git a/Documentation/technical/api-trace2.txt b/Documentation/technical/api-trace2.txt
index 43adbf00eb..8b6a5e6d4b 100644
--- a/Documentation/technical/api-trace2.txt
+++ b/Documentation/technical/api-trace2.txt
@@ -22,21 +22,41 @@ Targets are defined using a VTable allowing easy extension to other
 formats in the future.  This might be used to define a binary format,
 for example.
 
+Trace2 is controlled using `trace2.*` config values in the system and
+global config files and `GIT_TR2*` environment variables.  Trace2 does
+not read from repo local or worktree config files or respect `-c`
+command line config settings.
+
 == Trace2 Targets
 
 Trace2 defines the following set of Trace2 Targets.
 Format details are given in a later section.
 
-`GIT_TR2` (NORMAL)::
+=== The Normal Format Target
+
+The normal format target is a tradition printf format and similar
+to GIT_TRACE format.  This format is enabled with the `GIT_TR`
+environment variable or the `trace2.normalTarget` system or global
+config setting.
+
+For example
 
-	a simple printf format like GIT_TRACE.
-+
 ------------
 $ export GIT_TR2=~/log.normal
 $ git version
 git version 2.20.1.155.g426c96fcdb
 ------------
-+
+
+or
+
+------------
+$ git config --global trace2.normalTarget ~/log.normal
+$ git version
+git version 2.20.1.155.g426c96fcdb
+------------
+
+yields
+
 ------------
 $ cat ~/log.normal
 12:28:42.620009 common-main.c:38                  version 2.20.1.155.g426c96fcdb
@@ -46,17 +66,32 @@ $ cat ~/log.normal
 12:28:42.621250 trace2/tr2_tgt_normal.c:124       atexit elapsed:0.001265 code:0
 ------------
 
-`GIT_TR2_PERF` (PERF)::
+=== The Performance Format Target
+
+The performance format target (PERF) is a column-based format to
+replace GIT_TRACE_PERFORMANCE and is suitable for development and
+testing, possibly to complement tools like gprof.  This format is
+enabled with the `GIT_TR2_PERF` environment variable or the
+`trace2.perfTarget` system or global config setting.
+
+For example
 
-	a column-based format to replace GIT_TRACE_PERFORMANCE suitable for
-	development and testing, possibly to complement tools like gprof.
-+
 ------------
 $ export GIT_TR2_PERF=~/log.perf
 $ git version
 git version 2.20.1.155.g426c96fcdb
 ------------
-+
+
+or
+
+------------
+$ git config --global trace2.perfTarget ~/log.perf
+$ git version
+git version 2.20.1.155.g426c96fcdb
+------------
+
+yields
+
 ------------
 $ cat ~/log.perf
 12:28:42.620675 common-main.c:38                  | d0 | main                     | version      |     |           |           |            | 2.20.1.155.g426c96fcdb
@@ -66,56 +101,46 @@ $ cat ~/log.perf
 12:28:42.621259 trace2/tr2_tgt_perf.c:211         | d0 | main                     | atexit       |     |  0.001265 |           |            | code:0
 ------------
 
-`GIT_TR2_EVENT` (EVENT)::
+=== The Event Format Target
+
+The event format target is a JSON-based format of event data suitable
+for telemetry analysis.  This format is enabled with the `GIT_TR2_EVENT`
+environment variable or the `trace2.eventTarget` system or global config
+setting.
+
+For example
 
-	a JSON-based format of event data suitable for telemetry analysis.
-+
 ------------
 $ export GIT_TR2_EVENT=~/log.event
 $ git version
 git version 2.20.1.155.g426c96fcdb
 ------------
-+
-------------
-$ cat ~/log.event
-{"event":"version","sid":"sid":"20190408T191610.507018Z-H9b68c35f-P028492","thread":"main","time":"2019-01-16T17:28:42.620713Z","file":"common-main.c","line":38,"evt":"1","exe":"2.20.1.155.g426c96fcdb"}
-{"event":"start","sid":"20190408T191610.507018Z-H9b68c35f-P028492","thread":"main","time":"2019-01-16T17:28:42.621027Z","file":"common-main.c","line":39,"t_abs":0.001173,"argv":["git","version"]}
-{"event":"cmd_name","sid":"20190408T191610.507018Z-H9b68c35f-P028492","thread":"main","time":"2019-01-16T17:28:42.621122Z","file":"git.c","line":432,"name":"version","hierarchy":"version"}
-{"event":"exit","sid":"20190408T191610.507018Z-H9b68c35f-P028492","thread":"main","time":"2019-01-16T17:28:42.621236Z","file":"git.c","line":662,"t_abs":0.001227,"code":0}
-{"event":"atexit","sid":"20190408T191610.507018Z-H9b68c35f-P028492","thread":"main","time":"2019-01-16T17:28:42.621268Z","file":"trace2/tr2_tgt_event.c","line":163,"t_abs":0.001265,"code":0}
-------------
-
-== Enabling a Target
-
-A Trace2 Target is enabled when the corresponding environment variable
-(`GIT_TR2`, `GIT_TR2_PERF`, or `GIT_TR2_EVENT`) is set.  The following
-values are recognized.
-
-`0`::
-`false`::
-
-	Disables the target.
 
-`1`::
-`true`::
+or
 
-	Enables the target and writes stream to `STDERR`.
-
-`[2-9]`::
+------------
+$ git config --global trace2.eventTarget ~/log.event
+$ git version
+git version 2.20.1.155.g426c96fcdb
+------------
 
-	Enables the target and writes to the already opened file descriptor.
+yields
 
-`<absolute-pathname>`::
+------------
+$ cat ~/log.event
+{"event":"version","sid":"sid":"20190408T191610.507018Z-H9b68c35f-P000059a8","thread":"main","time":"2019-01-16T17:28:42.620713Z","file":"common-main.c","line":38,"evt":"1","exe":"2.20.1.155.g426c96fcdb"}
+{"event":"start","sid":"20190408T191610.507018Z-H9b68c35f-P000059a8","thread":"main","time":"2019-01-16T17:28:42.621027Z","file":"common-main.c","line":39,"t_abs":0.001173,"argv":["git","version"]}
+{"event":"cmd_name","sid":"20190408T191610.507018Z-H9b68c35f-P000059a8","thread":"main","time":"2019-01-16T17:28:42.621122Z","file":"git.c","line":432,"name":"version","hierarchy":"version"}
+{"event":"exit","sid":"20190408T191610.507018Z-H9b68c35f-P000059a8","thread":"main","time":"2019-01-16T17:28:42.621236Z","file":"git.c","line":662,"t_abs":0.001227,"code":0}
+{"event":"atexit","sid":"20190408T191610.507018Z-H9b68c35f-P000059a8","thread":"main","time":"2019-01-16T17:28:42.621268Z","file":"trace2/tr2_tgt_event.c","line":163,"t_abs":0.001265,"code":0}
+------------
 
-	Enables the target, opens and writes to the file in append mode.
+=== Enabling a Target
 
-`af_unix:[<socket_type>:]<absolute-pathname>`::
+To enable a target, set the corresponding environment variable or
+system or global config value to one of the following:
 
-	Enables the target, opens and writes to a Unix Domain Socket
-	(on platforms that support them).
-+
-Socket type can be either `stream` or `dgram`.  If the socket type is
-omitted, Git will try both.
+include::../trace2-target-values.txt[]
 
 == Trace2 API
 
@@ -243,15 +268,16 @@ significantly affects program performance or behavior, such as
 	Emits a "def_param" messages for "important" configuration
 	settings.
 +
-The environment variable `GIT_TR2_CONFIG_PARAMS` can be set to a
+The environment variable `GIT_TR2_CONFIG_PARAMS` or the `trace2.configParams`
+config value can be set to a
 list of patterns of important configuration settings, for example:
 `core.*,remote.*.url`.  This function will iterate over all config
 settings and emit a "def_param" message for each match.
 
 `void trace2_cmd_set_config(const char *key, const char *value)`::
 
-	Emits a "def_param" message for a specific configuration
-	setting IFF it matches the `GIT_TR2_CONFIG_PARAMS` pattern.
+	Emits a "def_param" message for a new or updated key/value
+	pair IF `key` is considered important.
 +
 This is used to hook into `git_config_set()` and catch any
 configuration changes and update a value previously reported by
@@ -418,9 +444,6 @@ recursive tree walk.
 
 === NORMAL Format
 
-NORMAL format is enabled when the `GIT_TR2` environment variable is
-set.
-
 Events are written as lines of the form:
 
 ------------
@@ -437,8 +460,8 @@ Events are written as lines of the form:
 Note that this may contain embedded LF or CRLF characters that are
 not escaped, so the event may spill across multiple lines.
 
-If `GIT_TR2_BRIEF` is true, the `time`, `filename`, and `line` fields
-are omitted.
+If `GIT_TR2_BRIEF` or `trace2.normalBrief` is true, the `time`, `filename`,
+and `line` fields are omitted.
 
 This target is intended to be more of a summary (like GIT_TRACE) and
 less detailed than the other targets.  It ignores thread, region, and
@@ -446,9 +469,6 @@ data messages, for example.
 
 === PERF Format
 
-PERF format is enabled when the `GIT_TR2_PERF` environment variable
-is set.
-
 Events are written as lines of the form:
 
 ------------
@@ -508,8 +528,8 @@ This field is in anticipation of in-proc submodules in the future.
 15:33:33.532712 wt-status.c:2331                  | d0 | main                     | region_leave | r1  |  0.127568 |  0.001504 | status     | label:print
 ------------
 
-If `GIT_TR2_PERF_BRIEF` is true, the `time`, `file`, and `line`
-fields are omitted.
+If `GIT_TR2_PERF_BRIEF` or `trace2.perfBrief` is true, the `time`, `file`,
+and `line` fields are omitted.
 
 ------------
 d0 | main                     | region_leave | r1  |  0.011717 |  0.009122 | index      | label:preload
@@ -520,9 +540,6 @@ during development and is quite noisy.
 
 === EVENT Format
 
-EVENT format is enabled when the `GIT_TR2_EVENT` environment
-variable is set.
-
 Each event is a JSON-object containing multiple key/value pairs
 written as a single line and followed by a LF.
 
@@ -540,7 +557,7 @@ The following key/value pairs are common to all events:
 ------------
 {
 	"event":"version",
-	"sid":"20190408T191827.272759Z-H9b68c35f-P011764",
+	"sid":"20190408T191827.272759Z-H9b68c35f-P00003510",
 	"thread":"main",
 	"time":"2019-04-08T19:18:27.282761Z",
 	"file":"common-main.c",
@@ -576,9 +593,9 @@ The following key/value pairs are common to all events:
 `"repo":<repo-id>`::
 	when present, is the integer repo-id as described previously.
 
-If `GIT_TR2_EVENT_BRIEF` is true, the `file` and `line` fields are omitted
-from all events and the `time` field is only present on the "start" and
-"atexit" events.
+If `GIT_TR2_EVENT_BRIEF` or `trace2.eventBrief` is true, the `file`
+and `line` fields are omitted from all events and the `time` field is
+only present on the "start" and "atexit" events.
 
 ==== Event-Specific Key/Value Pairs
 
@@ -889,7 +906,7 @@ visited.
 The `category` field may be used in a future enhancement to
 do category-based filtering.
 +
-The `GIT_TR2_EVENT_NESTING` environment variable can be used to
+`GIT_TR2_EVENT_NESTING` or `trace2.eventNesting` can be used to
 filter deeply nested regions and data events.  It defaults to "2".
 
 `"region_leave"`::
diff --git a/Documentation/trace2-target-values.txt b/Documentation/trace2-target-values.txt
new file mode 100644
index 0000000000..27d3c64e66
--- /dev/null
+++ b/Documentation/trace2-target-values.txt
@@ -0,0 +1,10 @@
+--
+* `0` or `false` - Disables the target.
+* `1` or `true` - Writes to `STDERR`.
+* `[2-9]` - Writes to the already opened file descriptor.
+* `<absolute-pathname>` - Writes to the file in append mode.
+* `af_unix:[<socket_type>:]<absolute-pathname>` - Write to a
+Unix DomainSocket (on platforms that support them).  Socket
+type can be either `stream` or `dgram`; if omitted Git will
+try both.
+--
-- 
gitgitgadget

^ permalink raw reply	[flat|nested] 68+ messages in thread

* Re: [PATCH v4 06/10] trace2: use system/global config for default trace2 settings
  2019-04-15 20:39       ` [PATCH v4 06/10] trace2: use system/global config for default trace2 settings Jeff Hostetler via GitGitGadget
@ 2019-04-27 13:43         ` SZEDER Gábor
  2019-04-29 19:03           ` Jeff Hostetler
  0 siblings, 1 reply; 68+ messages in thread
From: SZEDER Gábor @ 2019-04-27 13:43 UTC (permalink / raw)
  To: Jeff Hostetler via GitGitGadget
  Cc: git, gitster, peff, jrnieder, steadmon, avarab, Jeff Hostetler

On Mon, Apr 15, 2019 at 01:39:47PM -0700, Jeff Hostetler via GitGitGadget wrote:
> From: Jeff Hostetler <jeffhost@microsoft.com>
> 
> Teach git to read the system and global config files for
> default Trace2 settings.  This allows system-wide Trace2 settings to
> be installed and inherited to make it easier to manage a collection of
> systems.
> 
> The original GIT_TR2* environment variables are loaded afterwards and
> can be used to override the system settings.
> 
> Only the system and global config files are used.  Repo and worktree
> local config files are ignored.  Likewise, the "-c" command line
> arguments are also ignored.  These limits are for performance reasons.
> 
> (1) For users not using Trace2, there should be minimal overhead to
> detect that Trace2 is not enabled.  In particular, Trace2 should not
> allocate lots of otherwise unused data strucutres.
> 
> (2) For accurate performance measurements, Trace2 should be initialized
> as early in the git process as possible, and before most of the normal
> git process initialization (which involves discovering the .git directory
> and reading a hierarchy of config files).

Reading the configuration that early causes unexpected and undesired
behavior change:

  $ sudo chmod a-rwx /usr/local/etc/gitconfig
  $ ./BUILDS/v2.21.0/bin/git
  usage: git [--version] [--help] [-C <path>] [-c <name>=<value>]
  <... snip rest of usage ...>
  $ strace ./BUILDS/v2.21.0/bin/git 2>&1 |grep config -c
  0
  $ ./git
  fatal: unable to access '/usr/local/etc/gitconfig': Permission denied
  $ ./git --version
  fatal: unable to access '/usr/local/etc/gitconfig': Permission denied

I think at least 'git', 'git --help', and 'git --version' should Just
Work, no matter what.


This breaks the 32 bit Linux build job on Travis CI, because:

  - In the 32 bit Docker image we change UID from root to regular user
    while preserving the environment, including $HOME.
    
  - Since $HOME is the default build prefix, Git will look for the
    system-wide configuration under '/root/etc/gitconfig', which fails
    as a regular user.

  - Our test harness checks early (i.e. earlier than setting
    GIT_CONFIG_NOSYSTEM=1) whether Git has been built successfully by
    attempting to run '$GIT_BUILD_DIR}/git', which fails because of
    the inaccessible system-wide config file, and in turn the harness
    assumes that Git hasn't been built and aborts.

  https://travis-ci.org/git/git/jobs/524403682#L1258


^ permalink raw reply	[flat|nested] 68+ messages in thread

* Re: [PATCH v4 06/10] trace2: use system/global config for default trace2 settings
  2019-04-27 13:43         ` SZEDER Gábor
@ 2019-04-29 19:03           ` Jeff Hostetler
  0 siblings, 0 replies; 68+ messages in thread
From: Jeff Hostetler @ 2019-04-29 19:03 UTC (permalink / raw)
  To: SZEDER Gábor, Jeff Hostetler via GitGitGadget
  Cc: git, gitster, peff, jrnieder, steadmon, avarab, Jeff Hostetler



On 4/27/2019 9:43 AM, SZEDER Gábor wrote:
> On Mon, Apr 15, 2019 at 01:39:47PM -0700, Jeff Hostetler via GitGitGadget wrote:
>> From: Jeff Hostetler <jeffhost@microsoft.com>
>>
>> Teach git to read the system and global config files for
>> default Trace2 settings.  This allows system-wide Trace2 settings to
>> be installed and inherited to make it easier to manage a collection of
>> systems.
>>
>> The original GIT_TR2* environment variables are loaded afterwards and
>> can be used to override the system settings.
>>
>> Only the system and global config files are used.  Repo and worktree
>> local config files are ignored.  Likewise, the "-c" command line
>> arguments are also ignored.  These limits are for performance reasons.
>>
>> (1) For users not using Trace2, there should be minimal overhead to
>> detect that Trace2 is not enabled.  In particular, Trace2 should not
>> allocate lots of otherwise unused data strucutres.
>>
>> (2) For accurate performance measurements, Trace2 should be initialized
>> as early in the git process as possible, and before most of the normal
>> git process initialization (which involves discovering the .git directory
>> and reading a hierarchy of config files).
> 
> Reading the configuration that early causes unexpected and undesired
> behavior change:
> 
>    $ sudo chmod a-rwx /usr/local/etc/gitconfig
>    $ ./BUILDS/v2.21.0/bin/git
>    usage: git [--version] [--help] [-C <path>] [-c <name>=<value>]
>    <... snip rest of usage ...>
>    $ strace ./BUILDS/v2.21.0/bin/git 2>&1 |grep config -c
>    0
>    $ ./git
>    fatal: unable to access '/usr/local/etc/gitconfig': Permission denied
>    $ ./git --version
>    fatal: unable to access '/usr/local/etc/gitconfig': Permission denied
> 
> I think at least 'git', 'git --help', and 'git --version' should Just
> Work, no matter what.
> 
> 
> This breaks the 32 bit Linux build job on Travis CI, because:
> 
>    - In the 32 bit Docker image we change UID from root to regular user
>      while preserving the environment, including $HOME.
>      
>    - Since $HOME is the default build prefix, Git will look for the
>      system-wide configuration under '/root/etc/gitconfig', which fails
>      as a regular user.
> 
>    - Our test harness checks early (i.e. earlier than setting
>      GIT_CONFIG_NOSYSTEM=1) whether Git has been built successfully by
>      attempting to run '$GIT_BUILD_DIR}/git', which fails because of
>      the inaccessible system-wide config file, and in turn the harness
>      assumes that Git hasn't been built and aborts.
> 
>    https://travis-ci.org/git/git/jobs/524403682#L1258
> 

It appears that config.c:do_git_config_sequence() passes flags = 0
to access_or_die() rather than ACCESS_EACCES_OK as it does for the
other scopes.  This causes the fatal error, rather than ignoring the
problem.

Reasons for this were discussed in:
     4698c8feb1 config: allow inaccessible configuration under $HOME

I'll push a fix shortly.

Thanks
Jeff

^ permalink raw reply	[flat|nested] 68+ messages in thread

* [PATCH v5 00/11] trace2: load trace2 settings from system config
  2019-04-15 20:39     ` [PATCH v4 " Jeff Hostetler via GitGitGadget
                         ` (9 preceding siblings ...)
  2019-04-15 20:39       ` [PATCH v4 10/10] trace2: update docs to describe system/global config settings Jeff Hostetler via GitGitGadget
@ 2019-04-29 20:14       ` Jeff Hostetler via GitGitGadget
  2019-04-29 20:14         ` [PATCH v5 01/11] config: initialize opts structure in repo_read_config() Jeff Hostetler via GitGitGadget
                           ` (11 more replies)
  10 siblings, 12 replies; 68+ messages in thread
From: Jeff Hostetler via GitGitGadget @ 2019-04-29 20:14 UTC (permalink / raw)
  To: git; +Cc: gitster, peff, jrnieder, steadmon, avarab, Junio C Hamano

Version 4 fixes a few clang-format warnings and simplifies the PID field in
the SID.

Jeff Hostetler (11):
  config: initialize opts structure in repo_read_config()
  trace2: refactor setting process starting time
  trace2: add absolute elapsed time to start event
  trace2: find exec-dir before trace2 initialization
  config: add read_very_early_config()
  trace2: use system/global config for default trace2 settings
  trace2: report peak memory usage of the process
  trace2: clarify UTC datetime formatting
  trace2: make SIDs more unique
  trace2: update docs to describe system/global config settings
  trace2: fixup access problem on /etc/gitconfig in
    read_very_early_config

 Documentation/config.txt                 |   2 +
 Documentation/config/trace2.txt          |  56 ++++++++
 Documentation/technical/api-trace2.txt   | 176 +++++++++++++----------
 Documentation/trace2-target-values.txt   |  10 ++
 Makefile                                 |   1 +
 common-main.c                            |   8 +-
 compat/mingw.c                           |   2 +
 compat/win32/trace2_win32_process_info.c |  50 ++++++-
 config.c                                 |  30 +++-
 config.h                                 |   5 +
 t/t0210-trace2-normal.sh                 |  49 ++++++-
 t/t0211-trace2-perf.sh                   |  43 ++++--
 t/t0212-trace2-event.sh                  |  42 +++++-
 trace2.c                                 |  21 ++-
 trace2.h                                 |  43 ++++--
 trace2/tr2_cfg.c                         |   7 +-
 trace2/tr2_dst.c                         |  26 ++--
 trace2/tr2_dst.h                         |   3 +-
 trace2/tr2_sid.c                         |  53 ++++++-
 trace2/tr2_sysenv.c                      | 127 ++++++++++++++++
 trace2/tr2_sysenv.h                      |  36 +++++
 trace2/tr2_tbuf.c                        |  19 ++-
 trace2/tr2_tbuf.h                        |   5 +-
 trace2/tr2_tgt.h                         |   1 +
 trace2/tr2_tgt_event.c                   |  53 +++----
 trace2/tr2_tgt_normal.c                  |  19 +--
 trace2/tr2_tgt_perf.c                    |  23 +--
 trace2/tr2_tls.c                         |  38 +++--
 trace2/tr2_tls.h                         |   8 +-
 29 files changed, 752 insertions(+), 204 deletions(-)
 create mode 100644 Documentation/config/trace2.txt
 create mode 100644 Documentation/trace2-target-values.txt
 create mode 100644 trace2/tr2_sysenv.c
 create mode 100644 trace2/tr2_sysenv.h


base-commit: 041f5ea1cf987a4068ef5f39ba0a09be85952064
Published-As: https://github.com/gitgitgadget/git/releases/tag/pr-169%2Fjeffhostetler%2Fcore-tr2-startup-and-sysenv-v5
Fetch-It-Via: git fetch https://github.com/gitgitgadget/git pr-169/jeffhostetler/core-tr2-startup-and-sysenv-v5
Pull-Request: https://github.com/gitgitgadget/git/pull/169

Range-diff vs v4:

  1:  f6653f1c59 =  1:  f6653f1c59 config: initialize opts structure in repo_read_config()
  2:  48e34834b6 =  2:  48e34834b6 trace2: refactor setting process starting time
  3:  175371fb54 =  3:  175371fb54 trace2: add absolute elapsed time to start event
  4:  94729b284c =  4:  94729b284c trace2: find exec-dir before trace2 initialization
  5:  b0fe1385f1 =  5:  b0fe1385f1 config: add read_very_early_config()
  6:  550cad6189 =  6:  550cad6189 trace2: use system/global config for default trace2 settings
  7:  56d8ce3fd6 =  7:  56d8ce3fd6 trace2: report peak memory usage of the process
  8:  196a9d2c85 =  8:  196a9d2c85 trace2: clarify UTC datetime formatting
  9:  9fdcb50140 =  9:  9fdcb50140 trace2: make SIDs more unique
 10:  3414016d04 = 10:  3414016d04 trace2: update docs to describe system/global config settings
  -:  ---------- > 11:  18ce795360 trace2: fixup access problem on /etc/gitconfig in read_very_early_config

-- 
gitgitgadget

^ permalink raw reply	[flat|nested] 68+ messages in thread

* [PATCH v5 01/11] config: initialize opts structure in repo_read_config()
  2019-04-29 20:14       ` [PATCH v5 00/11] trace2: load trace2 settings from system config Jeff Hostetler via GitGitGadget
@ 2019-04-29 20:14         ` Jeff Hostetler via GitGitGadget
  2019-04-29 20:14         ` [PATCH v5 02/11] trace2: refactor setting process starting time Jeff Hostetler via GitGitGadget
                           ` (10 subsequent siblings)
  11 siblings, 0 replies; 68+ messages in thread
From: Jeff Hostetler via GitGitGadget @ 2019-04-29 20:14 UTC (permalink / raw)
  To: git
  Cc: gitster, peff, jrnieder, steadmon, avarab, Junio C Hamano,
	Jeff Hostetler

From: Jeff Hostetler <jeffhost@microsoft.com>

Initialize opts structure in repo_read_config().

This change fixes a crash in later commit after a new field is added
to the structure.

In commit 3b256228a66f8587661481ef3e08259864f3ba2a, repo_read_config()
was added.  It only initializes 3 fields in the opts structure.  It is
passed to config_with_options() and then to do_git_config_sequence().
However, do_git_config_sequence() drops the opts on the floor and calls
git_config_from_file() rather than git_config_from_file_with_options(),
so that may be why this hasn't been a problem in the past.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Jeff Hostetler <jeffhost@microsoft.com>
---
 config.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/config.c b/config.c
index 0f0cdd8c0f..c809f76219 100644
--- a/config.c
+++ b/config.c
@@ -2011,7 +2011,7 @@ int git_configset_get_pathname(struct config_set *cs, const char *key, const cha
 /* Functions use to read configuration from a repository */
 static void repo_read_config(struct repository *repo)
 {
-	struct config_options opts;
+	struct config_options opts = { 0 };
 
 	opts.respect_includes = 1;
 	opts.commondir = repo->commondir;
-- 
gitgitgadget


^ permalink raw reply	[flat|nested] 68+ messages in thread

* [PATCH v5 02/11] trace2: refactor setting process starting time
  2019-04-29 20:14       ` [PATCH v5 00/11] trace2: load trace2 settings from system config Jeff Hostetler via GitGitGadget
  2019-04-29 20:14         ` [PATCH v5 01/11] config: initialize opts structure in repo_read_config() Jeff Hostetler via GitGitGadget
@ 2019-04-29 20:14         ` Jeff Hostetler via GitGitGadget
  2019-04-29 20:14         ` [PATCH v5 03/11] trace2: add absolute elapsed time to start event Jeff Hostetler via GitGitGadget
                           ` (9 subsequent siblings)
  11 siblings, 0 replies; 68+ messages in thread
From: Jeff Hostetler via GitGitGadget @ 2019-04-29 20:14 UTC (permalink / raw)
  To: git
  Cc: gitster, peff, jrnieder, steadmon, avarab, Junio C Hamano,
	Jeff Hostetler

From: Jeff Hostetler <jeffhost@microsoft.com>

Create trace2_initialize_clock() and call from main() to capture
process start time in isolation and before other sub-systems are
ready.

Signed-off-by: Jeff Hostetler <jeffhost@microsoft.com>
---
 Documentation/technical/api-trace2.txt | 12 ++++++--
 common-main.c                          |  2 ++
 compat/mingw.c                         |  2 ++
 trace2.c                               |  7 ++++-
 trace2.h                               | 17 ++++++++++++
 trace2/tr2_tls.c                       | 38 ++++++++++++++++----------
 trace2/tr2_tls.h                       |  8 +++++-
 7 files changed, 67 insertions(+), 19 deletions(-)

diff --git a/Documentation/technical/api-trace2.txt b/Documentation/technical/api-trace2.txt
index 2de565fa3d..f37fccf1da 100644
--- a/Documentation/technical/api-trace2.txt
+++ b/Documentation/technical/api-trace2.txt
@@ -160,17 +160,23 @@ purposes.
 
 These are concerned with the lifetime of the overall git process.
 
+`void trace2_initialize_clock()`::
+
+	Initialize the Trace2 start clock and nothing else.  This should
+	be called at the very top of main() to capture the process start
+	time and reduce startup order dependencies.
+
 `void trace2_initialize()`::
 
 	Determines if any Trace2 Targets should be enabled and
-	initializes the Trace2 facility.  This includes starting the
-	elapsed time clocks and thread local storage (TLS).
+	initializes the Trace2 facility.  This includes setting up the
+	Trace2 thread local storage (TLS).
 +
 This function emits a "version" message containing the version of git
 and the Trace2 protocol.
 +
 This function should be called from `main()` as early as possible in
-the life of the process.
+the life of the process after essential process initialization.
 
 `int trace2_is_enabled()`::
 
diff --git a/common-main.c b/common-main.c
index d484aec209..6137af0e63 100644
--- a/common-main.c
+++ b/common-main.c
@@ -27,6 +27,8 @@ int main(int argc, const char **argv)
 {
 	int result;
 
+	trace2_initialize_clock();
+
 	/*
 	 * Always open file descriptors 0/1/2 to avoid clobbering files
 	 * in die().  It also avoids messing up when the pipes are dup'ed
diff --git a/compat/mingw.c b/compat/mingw.c
index 6b04514cdc..a2f74aca6a 100644
--- a/compat/mingw.c
+++ b/compat/mingw.c
@@ -2569,6 +2569,8 @@ void mingw_startup(void)
 	wchar_t **wenv, **wargv;
 	_startupinfo si;
 
+	trace2_initialize_clock();
+
 	maybe_redirect_std_handles();
 
 	/* get wide char arguments and environment */
diff --git a/trace2.c b/trace2.c
index ccccd4ef09..6dd51e6aa5 100644
--- a/trace2.c
+++ b/trace2.c
@@ -142,6 +142,11 @@ static void tr2main_signal_handler(int signo)
 	raise(signo);
 }
 
+void trace2_initialize_clock(void)
+{
+	tr2tls_start_process_clock();
+}
+
 void trace2_initialize_fl(const char *file, int line)
 {
 	struct tr2_tgt *tgt_j;
@@ -428,7 +433,7 @@ void trace2_thread_start_fl(const char *file, int line, const char *thread_name)
 	us_now = getnanotime() / 1000;
 	us_elapsed_absolute = tr2tls_absolute_elapsed(us_now);
 
-	tr2tls_create_self(thread_name);
+	tr2tls_create_self(thread_name, us_now);
 
 	for_each_wanted_builtin (j, tgt_j)
 		if (tgt_j->pfn_thread_start_fl)
diff --git a/trace2.h b/trace2.h
index ae5020d0e6..8f89e70c44 100644
--- a/trace2.h
+++ b/trace2.h
@@ -19,6 +19,23 @@ struct json_writer;
  * [] trace2_printf*    -- legacy trace[1] messages.
  */
 
+/*
+ * Initialize the TRACE2 clock and do nothing else, in particular
+ * no mallocs, no system inspection, and no environment inspection.
+ *
+ * This should be called at the very top of main() to capture the
+ * process start time.  This is intended to reduce chicken-n-egg
+ * bootstrap pressure.
+ *
+ * It is safe to call this more than once.  This allows capturing
+ * absolute startup costs on Windows which uses a little trickery
+ * to do setup work before common-main.c:main() is called.
+ *
+ * The main trace2_initialize_fl() may be called a little later
+ * after more infrastructure is established.
+ */
+void trace2_initialize_clock(void);
+
 /*
  * Initialize TRACE2 tracing facility if any of the builtin TRACE2
  * targets are enabled in the environment.  Emits a 'version' event.
diff --git a/trace2/tr2_tls.c b/trace2/tr2_tls.c
index 8e65b0361d..e76d8c5d92 100644
--- a/trace2/tr2_tls.c
+++ b/trace2/tr2_tls.c
@@ -10,16 +10,30 @@
 #define TR2_REGION_NESTING_INITIAL_SIZE (100)
 
 static struct tr2tls_thread_ctx *tr2tls_thread_main;
-static uint64_t tr2tls_us_start_main;
+static uint64_t tr2tls_us_start_process;
 
 static pthread_mutex_t tr2tls_mutex;
 static pthread_key_t tr2tls_key;
 
 static int tr2_next_thread_id; /* modify under lock */
 
-struct tr2tls_thread_ctx *tr2tls_create_self(const char *thread_name)
+void tr2tls_start_process_clock(void)
+{
+	if (tr2tls_us_start_process)
+		return;
+
+	/*
+	 * Keep the absolute start time of the process (i.e. the main
+	 * process) in a fixed variable since other threads need to
+	 * access it.  This allows them to do that without a lock on
+	 * main thread's array data (because of reallocs).
+	 */
+	tr2tls_us_start_process = getnanotime() / 1000;
+}
+
+struct tr2tls_thread_ctx *tr2tls_create_self(const char *thread_name,
+					     uint64_t us_thread_start)
 {
-	uint64_t us_now = getnanotime() / 1000;
 	struct tr2tls_thread_ctx *ctx = xcalloc(1, sizeof(*ctx));
 
 	/*
@@ -29,7 +43,7 @@ struct tr2tls_thread_ctx *tr2tls_create_self(const char *thread_name)
 	 */
 	ctx->alloc = TR2_REGION_NESTING_INITIAL_SIZE;
 	ctx->array_us_start = (uint64_t *)xcalloc(ctx->alloc, sizeof(uint64_t));
-	ctx->array_us_start[ctx->nr_open_regions++] = us_now;
+	ctx->array_us_start[ctx->nr_open_regions++] = us_thread_start;
 
 	ctx->thread_id = tr2tls_locked_increment(&tr2_next_thread_id);
 
@@ -55,7 +69,7 @@ struct tr2tls_thread_ctx *tr2tls_get_self(void)
 	 * here and silently continue.
 	 */
 	if (!ctx)
-		ctx = tr2tls_create_self("unknown");
+		ctx = tr2tls_create_self("unknown", getnanotime() / 1000);
 
 	return ctx;
 }
@@ -124,22 +138,18 @@ uint64_t tr2tls_absolute_elapsed(uint64_t us)
 	if (!tr2tls_thread_main)
 		return 0;
 
-	return us - tr2tls_us_start_main;
+	return us - tr2tls_us_start_process;
 }
 
 void tr2tls_init(void)
 {
+	tr2tls_start_process_clock();
+
 	pthread_key_create(&tr2tls_key, NULL);
 	init_recursive_mutex(&tr2tls_mutex);
 
-	tr2tls_thread_main = tr2tls_create_self("main");
-	/*
-	 * Keep a copy of the absolute start time of the main thread
-	 * in a fixed variable since other threads need to access it.
-	 * This also eliminates the need to lock accesses to the main
-	 * thread's array (because of reallocs).
-	 */
-	tr2tls_us_start_main = tr2tls_thread_main->array_us_start[0];
+	tr2tls_thread_main =
+		tr2tls_create_self("main", tr2tls_us_start_process);
 }
 
 void tr2tls_release(void)
diff --git a/trace2/tr2_tls.h b/trace2/tr2_tls.h
index bb80e3f8e7..b1e327a928 100644
--- a/trace2/tr2_tls.h
+++ b/trace2/tr2_tls.h
@@ -31,7 +31,8 @@ struct tr2tls_thread_ctx {
  * In this and all following functions the term "self" refers to the
  * current thread.
  */
-struct tr2tls_thread_ctx *tr2tls_create_self(const char *thread_name);
+struct tr2tls_thread_ctx *tr2tls_create_self(const char *thread_name,
+					     uint64_t us_thread_start);
 
 /*
  * Get our TLS data.
@@ -94,4 +95,9 @@ void tr2tls_release(void);
  */
 int tr2tls_locked_increment(int *p);
 
+/*
+ * Capture the process start time and do nothing else.
+ */
+void tr2tls_start_process_clock(void);
+
 #endif /* TR2_TLS_H */
-- 
gitgitgadget


^ permalink raw reply	[flat|nested] 68+ messages in thread

* [PATCH v5 03/11] trace2: add absolute elapsed time to start event
  2019-04-29 20:14       ` [PATCH v5 00/11] trace2: load trace2 settings from system config Jeff Hostetler via GitGitGadget
  2019-04-29 20:14         ` [PATCH v5 01/11] config: initialize opts structure in repo_read_config() Jeff Hostetler via GitGitGadget
  2019-04-29 20:14         ` [PATCH v5 02/11] trace2: refactor setting process starting time Jeff Hostetler via GitGitGadget
@ 2019-04-29 20:14         ` Jeff Hostetler via GitGitGadget
  2019-04-29 20:14         ` [PATCH v5 04/11] trace2: find exec-dir before trace2 initialization Jeff Hostetler via GitGitGadget
                           ` (8 subsequent siblings)
  11 siblings, 0 replies; 68+ messages in thread
From: Jeff Hostetler via GitGitGadget @ 2019-04-29 20:14 UTC (permalink / raw)
  To: git
  Cc: gitster, peff, jrnieder, steadmon, avarab, Junio C Hamano,
	Jeff Hostetler

From: Jeff Hostetler <jeffhost@microsoft.com>

Add elapsed process time to "start" event to measure
the performance of early process startup.

Signed-off-by: Jeff Hostetler <jeffhost@microsoft.com>
---
 Documentation/technical/api-trace2.txt | 11 ++++++-----
 t/t0211-trace2-perf.sh                 | 12 ++++++------
 trace2.c                               |  8 +++++++-
 trace2/tr2_tgt.h                       |  1 +
 trace2/tr2_tgt_event.c                 |  5 ++++-
 trace2/tr2_tgt_normal.c                |  3 ++-
 trace2/tr2_tgt_perf.c                  |  7 ++++---
 7 files changed, 30 insertions(+), 17 deletions(-)

diff --git a/Documentation/technical/api-trace2.txt b/Documentation/technical/api-trace2.txt
index f37fccf1da..baaa1153bb 100644
--- a/Documentation/technical/api-trace2.txt
+++ b/Documentation/technical/api-trace2.txt
@@ -60,7 +60,7 @@ git version 2.20.1.155.g426c96fcdb
 ------------
 $ cat ~/log.perf
 12:28:42.620675 common-main.c:38                  | d0 | main                     | version      |     |           |           |            | 2.20.1.155.g426c96fcdb
-12:28:42.621001 common-main.c:39                  | d0 | main                     | start        |     |           |           |            | git version
+12:28:42.621001 common-main.c:39                  | d0 | main                     | start        |     |  0.001173 |           |            | git version
 12:28:42.621111 git.c:432                         | d0 | main                     | cmd_name     |     |           |           |            | version (version)
 12:28:42.621225 git.c:662                         | d0 | main                     | exit         |     |  0.001227 |           |            | code:0
 12:28:42.621259 trace2/tr2_tgt_perf.c:211         | d0 | main                     | atexit       |     |  0.001265 |           |            | code:0
@@ -79,7 +79,7 @@ git version 2.20.1.155.g426c96fcdb
 ------------
 $ cat ~/log.event
 {"event":"version","sid":"1547659722619736-11614","thread":"main","time":"2019-01-16 17:28:42.620713","file":"common-main.c","line":38,"evt":"1","exe":"2.20.1.155.g426c96fcdb"}
-{"event":"start","sid":"1547659722619736-11614","thread":"main","time":"2019-01-16 17:28:42.621027","file":"common-main.c","line":39,"argv":["git","version"]}
+{"event":"start","sid":"1547659722619736-11614","thread":"main","time":"2019-01-16 17:28:42.621027","file":"common-main.c","line":39,"t_abs":0.001173,"argv":["git","version"]}
 {"event":"cmd_name","sid":"1547659722619736-11614","thread":"main","time":"2019-01-16 17:28:42.621122","file":"git.c","line":432,"name":"version","hierarchy":"version"}
 {"event":"exit","sid":"1547659722619736-11614","thread":"main","time":"2019-01-16 17:28:42.621236","file":"git.c","line":662,"t_abs":0.001227,"code":0}
 {"event":"atexit","sid":"1547659722619736-11614","thread":"main","time":"2019-01-16 17:28:42.621268","file":"trace2/tr2_tgt_event.c","line":163,"t_abs":0.001265,"code":0}
@@ -601,6 +601,7 @@ from all events and the `time` field is only present on the "start" and
 {
 	"event":"start",
 	...
+	"t_abs":0.001227, # elapsed time in seconds
 	"argv":["git","version"]
 }
 ------------
@@ -1118,7 +1119,7 @@ $ git status
 
 $ cat ~/log.perf
 d0 | main                     | version      |     |           |           |            | 2.20.1.160.g5676107ecd.dirty
-d0 | main                     | start        |     |           |           |            | git status
+d0 | main                     | start        |     |  0.001173 |           |            | git status
 d0 | main                     | def_repo     | r1  |           |           |            | worktree:/Users/jeffhost/work/gfw
 d0 | main                     | cmd_name     |     |           |           |            | status (status)
 ...
@@ -1163,7 +1164,7 @@ $ git status
 ...
 $ cat ~/log.perf
 d0 | main                     | version      |     |           |           |            | 2.20.1.162.gb4ccea44db.dirty
-d0 | main                     | start        |     |           |           |            | git status
+d0 | main                     | start        |     |  0.001173 |           |            | git status
 d0 | main                     | def_repo     | r1  |           |           |            | worktree:/Users/jeffhost/work/gfw
 d0 | main                     | cmd_name     |     |           |           |            | status (status)
 ...
@@ -1219,7 +1220,7 @@ $ git status
 ...
 $ cat ~/log.perf
 d0 | main                     | version      |     |           |           |            | 2.20.1.156.gf9916ae094.dirty
-d0 | main                     | start        |     |           |           |            | git status
+d0 | main                     | start        |     |  0.001173 |           |            | git status
 d0 | main                     | def_repo     | r1  |           |           |            | worktree:/Users/jeffhost/work/gfw
 d0 | main                     | cmd_name     |     |           |           |            | status (status)
 d0 | main                     | region_enter | r1  |  0.001791 |           | index      | label:do_read_index .git/index
diff --git a/t/t0211-trace2-perf.sh b/t/t0211-trace2-perf.sh
index 953e2f7847..c9694b29f7 100755
--- a/t/t0211-trace2-perf.sh
+++ b/t/t0211-trace2-perf.sh
@@ -50,7 +50,7 @@ test_expect_success 'perf stream, return code 0' '
 	perl "$TEST_DIRECTORY/t0211/scrub_perf.perl" <trace.perf >actual &&
 	cat >expect <<-EOF &&
 		d0|main|version|||||$V
-		d0|main|start|||||_EXE_ trace2 001return 0
+		d0|main|start||_T_ABS_|||_EXE_ trace2 001return 0
 		d0|main|cmd_name|||||trace2 (trace2)
 		d0|main|exit||_T_ABS_|||code:0
 		d0|main|atexit||_T_ABS_|||code:0
@@ -64,7 +64,7 @@ test_expect_success 'perf stream, return code 1' '
 	perl "$TEST_DIRECTORY/t0211/scrub_perf.perl" <trace.perf >actual &&
 	cat >expect <<-EOF &&
 		d0|main|version|||||$V
-		d0|main|start|||||_EXE_ trace2 001return 1
+		d0|main|start||_T_ABS_|||_EXE_ trace2 001return 1
 		d0|main|cmd_name|||||trace2 (trace2)
 		d0|main|exit||_T_ABS_|||code:1
 		d0|main|atexit||_T_ABS_|||code:1
@@ -82,7 +82,7 @@ test_expect_success 'perf stream, error event' '
 	perl "$TEST_DIRECTORY/t0211/scrub_perf.perl" <trace.perf >actual &&
 	cat >expect <<-EOF &&
 		d0|main|version|||||$V
-		d0|main|start|||||_EXE_ trace2 003error '\''hello world'\'' '\''this is a test'\''
+		d0|main|start||_T_ABS_|||_EXE_ trace2 003error '\''hello world'\'' '\''this is a test'\''
 		d0|main|cmd_name|||||trace2 (trace2)
 		d0|main|error|||||hello world
 		d0|main|error|||||this is a test
@@ -128,15 +128,15 @@ test_expect_success 'perf stream, child processes' '
 	perl "$TEST_DIRECTORY/t0211/scrub_perf.perl" <trace.perf >actual &&
 	cat >expect <<-EOF &&
 		d0|main|version|||||$V
-		d0|main|start|||||_EXE_ trace2 004child test-tool trace2 004child test-tool trace2 001return 0
+		d0|main|start||_T_ABS_|||_EXE_ trace2 004child test-tool trace2 004child test-tool trace2 001return 0
 		d0|main|cmd_name|||||trace2 (trace2)
 		d0|main|child_start||_T_ABS_|||[ch0] class:? argv: test-tool trace2 004child test-tool trace2 001return 0
 		d1|main|version|||||$V
-		d1|main|start|||||_EXE_ trace2 004child test-tool trace2 001return 0
+		d1|main|start||_T_ABS_|||_EXE_ trace2 004child test-tool trace2 001return 0
 		d1|main|cmd_name|||||trace2 (trace2/trace2)
 		d1|main|child_start||_T_ABS_|||[ch0] class:? argv: test-tool trace2 001return 0
 		d2|main|version|||||$V
-		d2|main|start|||||_EXE_ trace2 001return 0
+		d2|main|start||_T_ABS_|||_EXE_ trace2 001return 0
 		d2|main|cmd_name|||||trace2 (trace2/trace2/trace2)
 		d2|main|exit||_T_ABS_|||code:0
 		d2|main|atexit||_T_ABS_|||code:0
diff --git a/trace2.c b/trace2.c
index 6dd51e6aa5..1c180062dd 100644
--- a/trace2.c
+++ b/trace2.c
@@ -182,13 +182,19 @@ void trace2_cmd_start_fl(const char *file, int line, const char **argv)
 {
 	struct tr2_tgt *tgt_j;
 	int j;
+	uint64_t us_now;
+	uint64_t us_elapsed_absolute;
 
 	if (!trace2_enabled)
 		return;
 
+	us_now = getnanotime() / 1000;
+	us_elapsed_absolute = tr2tls_absolute_elapsed(us_now);
+
 	for_each_wanted_builtin (j, tgt_j)
 		if (tgt_j->pfn_start_fl)
-			tgt_j->pfn_start_fl(file, line, argv);
+			tgt_j->pfn_start_fl(file, line, us_elapsed_absolute,
+					    argv);
 }
 
 int trace2_cmd_exit_fl(const char *file, int line, int code)
diff --git a/trace2/tr2_tgt.h b/trace2/tr2_tgt.h
index 297bb8ffbe..7b90469212 100644
--- a/trace2/tr2_tgt.h
+++ b/trace2/tr2_tgt.h
@@ -15,6 +15,7 @@ typedef void(tr2_tgt_term_t)(void);
 typedef void(tr2_tgt_evt_version_fl_t)(const char *file, int line);
 
 typedef void(tr2_tgt_evt_start_fl_t)(const char *file, int line,
+				     uint64_t us_elapsed_absolute,
 				     const char **argv);
 typedef void(tr2_tgt_evt_exit_fl_t)(const char *file, int line,
 				    uint64_t us_elapsed_absolute, int code);
diff --git a/trace2/tr2_tgt_event.c b/trace2/tr2_tgt_event.c
index 107cb5317d..89a4d3ae9a 100644
--- a/trace2/tr2_tgt_event.c
+++ b/trace2/tr2_tgt_event.c
@@ -122,13 +122,16 @@ static void fn_version_fl(const char *file, int line)
 	jw_release(&jw);
 }
 
-static void fn_start_fl(const char *file, int line, const char **argv)
+static void fn_start_fl(const char *file, int line,
+			uint64_t us_elapsed_absolute, const char **argv)
 {
 	const char *event_name = "start";
 	struct json_writer jw = JSON_WRITER_INIT;
+	double t_abs = (double)us_elapsed_absolute / 1000000.0;
 
 	jw_object_begin(&jw, 0);
 	event_fmt_prepare(event_name, file, line, NULL, &jw);
+	jw_object_double(&jw, "t_abs", 6, t_abs);
 	jw_object_inline_begin_array(&jw, "argv");
 	jw_array_argv(&jw, argv);
 	jw_end(&jw);
diff --git a/trace2/tr2_tgt_normal.c b/trace2/tr2_tgt_normal.c
index 547183d5b6..57f3e18f5b 100644
--- a/trace2/tr2_tgt_normal.c
+++ b/trace2/tr2_tgt_normal.c
@@ -81,7 +81,8 @@ static void fn_version_fl(const char *file, int line)
 	strbuf_release(&buf_payload);
 }
 
-static void fn_start_fl(const char *file, int line, const char **argv)
+static void fn_start_fl(const char *file, int line,
+			uint64_t us_elapsed_absolute, const char **argv)
 {
 	struct strbuf buf_payload = STRBUF_INIT;
 
diff --git a/trace2/tr2_tgt_perf.c b/trace2/tr2_tgt_perf.c
index f0746fcf86..9c3b4d8a0f 100644
--- a/trace2/tr2_tgt_perf.c
+++ b/trace2/tr2_tgt_perf.c
@@ -159,15 +159,16 @@ static void fn_version_fl(const char *file, int line)
 	strbuf_release(&buf_payload);
 }
 
-static void fn_start_fl(const char *file, int line, const char **argv)
+static void fn_start_fl(const char *file, int line,
+			uint64_t us_elapsed_absolute, const char **argv)
 {
 	const char *event_name = "start";
 	struct strbuf buf_payload = STRBUF_INIT;
 
 	sq_quote_argv_pretty(&buf_payload, argv);
 
-	perf_io_write_fl(file, line, event_name, NULL, NULL, NULL, NULL,
-			 &buf_payload);
+	perf_io_write_fl(file, line, event_name, NULL, &us_elapsed_absolute,
+			 NULL, NULL, &buf_payload);
 	strbuf_release(&buf_payload);
 }
 
-- 
gitgitgadget


^ permalink raw reply	[flat|nested] 68+ messages in thread

* [PATCH v5 04/11] trace2: find exec-dir before trace2 initialization
  2019-04-29 20:14       ` [PATCH v5 00/11] trace2: load trace2 settings from system config Jeff Hostetler via GitGitGadget
                           ` (2 preceding siblings ...)
  2019-04-29 20:14         ` [PATCH v5 03/11] trace2: add absolute elapsed time to start event Jeff Hostetler via GitGitGadget
@ 2019-04-29 20:14         ` Jeff Hostetler via GitGitGadget
  2019-04-29 20:14         ` [PATCH v5 05/11] config: add read_very_early_config() Jeff Hostetler via GitGitGadget
                           ` (7 subsequent siblings)
  11 siblings, 0 replies; 68+ messages in thread
From: Jeff Hostetler via GitGitGadget @ 2019-04-29 20:14 UTC (permalink / raw)
  To: git
  Cc: gitster, peff, jrnieder, steadmon, avarab, Junio C Hamano,
	Jeff Hostetler

From: Jeff Hostetler <jeffhost@microsoft.com>

Teach Git to resolve the executable directory before initializing
Trace2.  This allows the system configuration directory to be
discovered earlier (because it is sometimes relative to the prefix
or runtime-prefix).

This will be used by the next commit to allow trace2 settings to
be loaded from the system config.

Signed-off-by: Jeff Hostetler <jeffhost@microsoft.com>
---
 common-main.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/common-main.c b/common-main.c
index 6137af0e63..299ca62a72 100644
--- a/common-main.c
+++ b/common-main.c
@@ -37,12 +37,12 @@ int main(int argc, const char **argv)
 	sanitize_stdfds();
 	restore_sigpipe_to_default();
 
+	git_resolve_executable_dir(argv[0]);
+
 	trace2_initialize();
 	trace2_cmd_start(argv);
 	trace2_collect_process_info();
 
-	git_resolve_executable_dir(argv[0]);
-
 	git_setup_gettext();
 
 	initialize_the_repository();
-- 
gitgitgadget


^ permalink raw reply	[flat|nested] 68+ messages in thread

* [PATCH v5 05/11] config: add read_very_early_config()
  2019-04-29 20:14       ` [PATCH v5 00/11] trace2: load trace2 settings from system config Jeff Hostetler via GitGitGadget
                           ` (3 preceding siblings ...)
  2019-04-29 20:14         ` [PATCH v5 04/11] trace2: find exec-dir before trace2 initialization Jeff Hostetler via GitGitGadget
@ 2019-04-29 20:14         ` Jeff Hostetler via GitGitGadget
  2019-04-29 20:14         ` [PATCH v5 06/11] trace2: use system/global config for default trace2 settings Jeff Hostetler via GitGitGadget
                           ` (6 subsequent siblings)
  11 siblings, 0 replies; 68+ messages in thread
From: Jeff Hostetler via GitGitGadget @ 2019-04-29 20:14 UTC (permalink / raw)
  To: git
  Cc: gitster, peff, jrnieder, steadmon, avarab, Junio C Hamano,
	Jeff Hostetler

From: Jeff Hostetler <jeffhost@microsoft.com>

Created an even lighter version of read_early_config() that
only looks at system and global config settings.  It omits
repo-local, worktree-local, and command-line settings.

Signed-off-by: Jeff Hostetler <jeffhost@microsoft.com>
---
 config.c | 23 ++++++++++++++++++++---
 config.h |  4 ++++
 2 files changed, 24 insertions(+), 3 deletions(-)

diff --git a/config.c b/config.c
index c809f76219..d7a08713a8 100644
--- a/config.c
+++ b/config.c
@@ -1688,14 +1688,15 @@ static int do_git_config_sequence(const struct config_options *opts,
 		ret += git_config_from_file(fn, user_config, data);
 
 	current_parsing_scope = CONFIG_SCOPE_REPO;
-	if (repo_config && !access_or_die(repo_config, R_OK, 0))
+	if (!opts->ignore_repo && repo_config &&
+	    !access_or_die(repo_config, R_OK, 0))
 		ret += git_config_from_file(fn, repo_config, data);
 
 	/*
 	 * Note: this should have a new scope, CONFIG_SCOPE_WORKTREE.
 	 * But let's not complicate things before it's actually needed.
 	 */
-	if (repository_format_worktree_config) {
+	if (!opts->ignore_worktree && repository_format_worktree_config) {
 		char *path = git_pathdup("config.worktree");
 		if (!access_or_die(path, R_OK, 0))
 			ret += git_config_from_file(fn, path, data);
@@ -1703,7 +1704,7 @@ static int do_git_config_sequence(const struct config_options *opts,
 	}
 
 	current_parsing_scope = CONFIG_SCOPE_CMDLINE;
-	if (git_config_from_parameters(fn, data) < 0)
+	if (!opts->ignore_cmdline && git_config_from_parameters(fn, data) < 0)
 		die(_("unable to parse command-line config"));
 
 	current_parsing_scope = CONFIG_SCOPE_UNKNOWN;
@@ -1794,6 +1795,22 @@ void read_early_config(config_fn_t cb, void *data)
 	strbuf_release(&gitdir);
 }
 
+/*
+ * Read config but only enumerate system and global settings.
+ * Omit any repo-local, worktree-local, or command-line settings.
+ */
+void read_very_early_config(config_fn_t cb, void *data)
+{
+	struct config_options opts = { 0 };
+
+	opts.respect_includes = 1;
+	opts.ignore_repo = 1;
+	opts.ignore_worktree = 1;
+	opts.ignore_cmdline = 1;
+
+	config_with_options(cb, data, NULL, &opts);
+}
+
 static struct config_set_element *configset_find_element(struct config_set *cs, const char *key)
 {
 	struct config_set_element k;
diff --git a/config.h b/config.h
index ee5d3fa7b4..6a58d61d22 100644
--- a/config.h
+++ b/config.h
@@ -55,6 +55,9 @@ typedef int (*config_parser_event_fn_t)(enum config_event_t type,
 
 struct config_options {
 	unsigned int respect_includes : 1;
+	unsigned int ignore_repo : 1;
+	unsigned int ignore_worktree : 1;
+	unsigned int ignore_cmdline : 1;
 	const char *commondir;
 	const char *git_dir;
 	config_parser_event_fn_t event_fn;
@@ -83,6 +86,7 @@ extern int git_config_from_blob_oid(config_fn_t fn, const char *name,
 extern void git_config_push_parameter(const char *text);
 extern int git_config_from_parameters(config_fn_t fn, void *data);
 extern void read_early_config(config_fn_t cb, void *data);
+extern void read_very_early_config(config_fn_t cb, void *data);
 extern void git_config(config_fn_t fn, void *);
 extern int config_with_options(config_fn_t fn, void *,
 			       struct git_config_source *config_source,
-- 
gitgitgadget


^ permalink raw reply	[flat|nested] 68+ messages in thread

* [PATCH v5 06/11] trace2: use system/global config for default trace2 settings
  2019-04-29 20:14       ` [PATCH v5 00/11] trace2: load trace2 settings from system config Jeff Hostetler via GitGitGadget
                           ` (4 preceding siblings ...)
  2019-04-29 20:14         ` [PATCH v5 05/11] config: add read_very_early_config() Jeff Hostetler via GitGitGadget
@ 2019-04-29 20:14         ` Jeff Hostetler via GitGitGadget
  2019-04-29 20:14         ` [PATCH v5 07/11] trace2: report peak memory usage of the process Jeff Hostetler via GitGitGadget
                           ` (5 subsequent siblings)
  11 siblings, 0 replies; 68+ messages in thread
From: Jeff Hostetler via GitGitGadget @ 2019-04-29 20:14 UTC (permalink / raw)
  To: git
  Cc: gitster, peff, jrnieder, steadmon, avarab, Junio C Hamano,
	Jeff Hostetler

From: Jeff Hostetler <jeffhost@microsoft.com>

Teach git to read the system and global config files for
default Trace2 settings.  This allows system-wide Trace2 settings to
be installed and inherited to make it easier to manage a collection of
systems.

The original GIT_TR2* environment variables are loaded afterwards and
can be used to override the system settings.

Only the system and global config files are used.  Repo and worktree
local config files are ignored.  Likewise, the "-c" command line
arguments are also ignored.  These limits are for performance reasons.

(1) For users not using Trace2, there should be minimal overhead to
detect that Trace2 is not enabled.  In particular, Trace2 should not
allocate lots of otherwise unused data strucutres.

(2) For accurate performance measurements, Trace2 should be initialized
as early in the git process as possible, and before most of the normal
git process initialization (which involves discovering the .git directory
and reading a hierarchy of config files).

Signed-off-by: Jeff Hostetler <jeffhost@microsoft.com>
---
 Makefile                 |   1 +
 t/t0210-trace2-normal.sh |  49 +++++++++++++--
 t/t0211-trace2-perf.sh   |  31 ++++++++--
 t/t0212-trace2-event.sh  |  42 +++++++++++--
 trace2.c                 |   4 ++
 trace2.h                 |  12 ++--
 trace2/tr2_cfg.c         |   7 +--
 trace2/tr2_dst.c         |  26 ++++----
 trace2/tr2_dst.h         |   3 +-
 trace2/tr2_sysenv.c      | 127 +++++++++++++++++++++++++++++++++++++++
 trace2/tr2_sysenv.h      |  36 +++++++++++
 trace2/tr2_tgt_event.c   |  46 +++++++-------
 trace2/tr2_tgt_normal.c  |  16 ++---
 trace2/tr2_tgt_perf.c    |  16 ++---
 14 files changed, 340 insertions(+), 76 deletions(-)
 create mode 100644 trace2/tr2_sysenv.c
 create mode 100644 trace2/tr2_sysenv.h

diff --git a/Makefile b/Makefile
index 3e03290d8f..9ddfa3dfe7 100644
--- a/Makefile
+++ b/Makefile
@@ -1005,6 +1005,7 @@ LIB_OBJS += trace2/tr2_cfg.o
 LIB_OBJS += trace2/tr2_cmd_name.o
 LIB_OBJS += trace2/tr2_dst.o
 LIB_OBJS += trace2/tr2_sid.o
+LIB_OBJS += trace2/tr2_sysenv.o
 LIB_OBJS += trace2/tr2_tbuf.o
 LIB_OBJS += trace2/tr2_tgt_event.o
 LIB_OBJS += trace2/tr2_tgt_normal.o
diff --git a/t/t0210-trace2-normal.sh b/t/t0210-trace2-normal.sh
index 03a0aedb1d..8d17e1e6f1 100755
--- a/t/t0210-trace2-normal.sh
+++ b/t/t0210-trace2-normal.sh
@@ -3,6 +3,11 @@
 test_description='test trace2 facility (normal target)'
 . ./test-lib.sh
 
+# Turn off any inherited trace2 settings for this test.
+sane_unset GIT_TR2 GIT_TR2_PERF GIT_TR2_EVENT
+sane_unset GIT_TR2_BRIEF
+sane_unset GIT_TR2_CONFIG_PARAMS
+
 # Add t/helper directory to PATH so that we can use a relative
 # path to run nested instances of test-tool.exe (see 004child).
 # This helps with HEREDOC comparisons later.
@@ -15,11 +20,6 @@ PATH="$TTDIR:$PATH" && export PATH
 # Warning: So you may see extra lines in artifact files when
 # Warning: interactively debugging.
 
-# Turn off any inherited trace2 settings for this test.
-unset GIT_TR2 GIT_TR2_PERF GIT_TR2_EVENT
-unset GIT_TR2_BRIEF
-unset GIT_TR2_CONFIG_PARAMS
-
 V=$(git version | sed -e 's/^git version //') && export V
 
 # There are multiple trace2 targets: normal, perf, and event.
@@ -132,4 +132,43 @@ test_expect_success 'normal stream, error event' '
 	test_cmp expect actual
 '
 
+sane_unset GIT_TR2_BRIEF
+
+# Now test without environment variables and get all Trace2 settings
+# from the global config.
+
+test_expect_success 'using global config, normal stream, return code 0' '
+	test_when_finished "rm trace.normal actual expect" &&
+	test_config_global trace2.normalBrief 1 &&
+	test_config_global trace2.normalTarget "$(pwd)/trace.normal" &&
+	test-tool trace2 001return 0 &&
+	perl "$TEST_DIRECTORY/t0210/scrub_normal.perl" <trace.normal >actual &&
+	cat >expect <<-EOF &&
+		version $V
+		start _EXE_ trace2 001return 0
+		cmd_name trace2 (trace2)
+		exit elapsed:_TIME_ code:0
+		atexit elapsed:_TIME_ code:0
+	EOF
+	test_cmp expect actual
+'
+
+test_expect_success 'using global config with include' '
+	test_when_finished "rm trace.normal actual expect real.gitconfig" &&
+	test_config_global trace2.normalBrief 1 &&
+	test_config_global trace2.normalTarget "$(pwd)/trace.normal" &&
+	mv "$(pwd)/.gitconfig" "$(pwd)/real.gitconfig" &&
+	test_config_global include.path "$(pwd)/real.gitconfig" &&
+	test-tool trace2 001return 0 &&
+	perl "$TEST_DIRECTORY/t0210/scrub_normal.perl" <trace.normal >actual &&
+	cat >expect <<-EOF &&
+		version $V
+		start _EXE_ trace2 001return 0
+		cmd_name trace2 (trace2)
+		exit elapsed:_TIME_ code:0
+		atexit elapsed:_TIME_ code:0
+	EOF
+	test_cmp expect actual
+'
+
 test_done
diff --git a/t/t0211-trace2-perf.sh b/t/t0211-trace2-perf.sh
index c9694b29f7..b501e867af 100755
--- a/t/t0211-trace2-perf.sh
+++ b/t/t0211-trace2-perf.sh
@@ -3,6 +3,11 @@
 test_description='test trace2 facility (perf target)'
 . ./test-lib.sh
 
+# Turn off any inherited trace2 settings for this test.
+sane_unset GIT_TR2 GIT_TR2_PERF GIT_TR2_EVENT
+sane_unset GIT_TR2_PERF_BRIEF
+sane_unset GIT_TR2_CONFIG_PARAMS
+
 # Add t/helper directory to PATH so that we can use a relative
 # path to run nested instances of test-tool.exe (see 004child).
 # This helps with HEREDOC comparisons later.
@@ -15,11 +20,6 @@ PATH="$TTDIR:$PATH" && export PATH
 # Warning: So you may see extra lines in artifact files when
 # Warning: interactively debugging.
 
-# Turn off any inherited trace2 settings for this test.
-unset GIT_TR2 GIT_TR2_PERF GIT_TR2_EVENT
-unset GIT_TR2_PERF_BRIEF
-unset GIT_TR2_CONFIG_PARAMS
-
 V=$(git version | sed -e 's/^git version //') && export V
 
 # There are multiple trace2 targets: normal, perf, and event.
@@ -150,4 +150,25 @@ test_expect_success 'perf stream, child processes' '
 	test_cmp expect actual
 '
 
+sane_unset GIT_TR2_PERF_BRIEF
+
+# Now test without environment variables and get all Trace2 settings
+# from the global config.
+
+test_expect_success 'using global config, perf stream, return code 0' '
+	test_when_finished "rm trace.perf actual expect" &&
+	test_config_global trace2.perfBrief 1 &&
+	test_config_global trace2.perfTarget "$(pwd)/trace.perf" &&
+	test-tool trace2 001return 0 &&
+	perl "$TEST_DIRECTORY/t0211/scrub_perf.perl" <trace.perf >actual &&
+	cat >expect <<-EOF &&
+		d0|main|version|||||$V
+		d0|main|start||_T_ABS_|||_EXE_ trace2 001return 0
+		d0|main|cmd_name|||||trace2 (trace2)
+		d0|main|exit||_T_ABS_|||code:0
+		d0|main|atexit||_T_ABS_|||code:0
+	EOF
+	test_cmp expect actual
+'
+
 test_done
diff --git a/t/t0212-trace2-event.sh b/t/t0212-trace2-event.sh
index 028b6c5671..59adae8123 100755
--- a/t/t0212-trace2-event.sh
+++ b/t/t0212-trace2-event.sh
@@ -3,6 +3,11 @@
 test_description='test trace2 facility'
 . ./test-lib.sh
 
+# Turn off any inherited trace2 settings for this test.
+sane_unset GIT_TR2 GIT_TR2_PERF GIT_TR2_EVENT
+sane_unset GIT_TR2_BARE
+sane_unset GIT_TR2_CONFIG_PARAMS
+
 perl -MJSON::PP -e 0 >/dev/null 2>&1 && test_set_prereq JSON_PP
 
 # Add t/helper directory to PATH so that we can use a relative
@@ -17,11 +22,6 @@ PATH="$TTDIR:$PATH" && export PATH
 # Warning: So you may see extra lines in artifact files when
 # Warning: interactively debugging.
 
-# Turn off any inherited trace2 settings for this test.
-unset GIT_TR2 GIT_TR2_PERF GIT_TR2_EVENT
-unset GIT_TR2_BARE
-unset GIT_TR2_CONFIG_PARAMS
-
 V=$(git version | sed -e 's/^git version //') && export V
 
 # There are multiple trace2 targets: normal, perf, and event.
@@ -233,4 +233,36 @@ test_expect_success JSON_PP 'basic trace2_data' '
 	test_cmp expect actual
 '
 
+# Now test without environment variables and get all Trace2 settings
+# from the global config.
+
+test_expect_success JSON_PP 'using global config, event stream, error event' '
+	test_when_finished "rm trace.event actual expect" &&
+	test_config_global trace2.eventTarget "$(pwd)/trace.event" &&
+	test-tool trace2 003error "hello world" "this is a test" &&
+	perl "$TEST_DIRECTORY/t0212/parse_events.perl" <trace.event >actual &&
+	sed -e "s/^|//" >expect <<-EOF &&
+	|VAR1 = {
+	|  "_SID0_":{
+	|    "argv":[
+	|      "_EXE_",
+	|      "trace2",
+	|      "003error",
+	|      "hello world",
+	|      "this is a test"
+	|    ],
+	|    "errors":[
+	|      "%s",
+	|      "%s"
+	|    ],
+	|    "exit_code":0,
+	|    "hierarchy":"trace2",
+	|    "name":"trace2",
+	|    "version":"$V"
+	|  }
+	|};
+	EOF
+	test_cmp expect actual
+'
+
 test_done
diff --git a/trace2.c b/trace2.c
index 1c180062dd..490b3f071e 100644
--- a/trace2.c
+++ b/trace2.c
@@ -10,6 +10,7 @@
 #include "trace2/tr2_cmd_name.h"
 #include "trace2/tr2_dst.h"
 #include "trace2/tr2_sid.h"
+#include "trace2/tr2_sysenv.h"
 #include "trace2/tr2_tgt.h"
 #include "trace2/tr2_tls.h"
 
@@ -120,6 +121,7 @@ static void tr2main_atexit_handler(void)
 	tr2_sid_release();
 	tr2_cmd_name_release();
 	tr2_cfg_free_patterns();
+	tr2_sysenv_release();
 
 	trace2_enabled = 0;
 }
@@ -155,6 +157,8 @@ void trace2_initialize_fl(const char *file, int line)
 	if (trace2_enabled)
 		return;
 
+	tr2_sysenv_load();
+
 	if (!tr2_tgt_want_builtins())
 		return;
 	trace2_enabled = 1;
diff --git a/trace2.h b/trace2.h
index 8f89e70c44..894bfca7e0 100644
--- a/trace2.h
+++ b/trace2.h
@@ -38,7 +38,8 @@ void trace2_initialize_clock(void);
 
 /*
  * Initialize TRACE2 tracing facility if any of the builtin TRACE2
- * targets are enabled in the environment.  Emits a 'version' event.
+ * targets are enabled in the system config or the environment.
+ * Emits a 'version' event.
  *
  * Cleanup/Termination is handled automatically by a registered
  * atexit() routine.
@@ -125,10 +126,11 @@ void trace2_cmd_alias_fl(const char *file, int line, const char *alias,
  * Emit one or more 'def_param' events for "interesting" configuration
  * settings.
  *
- * The environment variable "GIT_TR2_CONFIG_PARAMS" can be set to a
- * list of patterns considered important.  For example:
- *
- *    GIT_TR2_CONFIG_PARAMS="core.*,remote.*.url"
+ * Use the TR2_SYSENV_CFG_PARAM setting to register a comma-separated
+ * list of patterns configured important.  For example:
+ *     git config --system trace2.configParams 'core.*,remote.*.url'
+ * or:
+ *     GIT_TR2_CONFIG_PARAMS=core.*,remote.*.url"
  *
  * Note: this routine does a read-only iteration on the config data
  * (using read_early_config()), so it must not be called until enough
diff --git a/trace2/tr2_cfg.c b/trace2/tr2_cfg.c
index b329921ac5..caa7f06948 100644
--- a/trace2/tr2_cfg.c
+++ b/trace2/tr2_cfg.c
@@ -1,8 +1,7 @@
 #include "cache.h"
 #include "config.h"
-#include "tr2_cfg.h"
-
-#define TR2_ENVVAR_CFG_PARAM "GIT_TR2_CONFIG_PARAMS"
+#include "trace2/tr2_cfg.h"
+#include "trace2/tr2_sysenv.h"
 
 static struct strbuf **tr2_cfg_patterns;
 static int tr2_cfg_count_patterns;
@@ -21,7 +20,7 @@ static int tr2_cfg_load_patterns(void)
 		return tr2_cfg_count_patterns;
 	tr2_cfg_loaded = 1;
 
-	envvar = getenv(TR2_ENVVAR_CFG_PARAM);
+	envvar = tr2_sysenv_get(TR2_SYSENV_CFG_PARAM);
 	if (!envvar || !*envvar)
 		return tr2_cfg_count_patterns;
 
diff --git a/trace2/tr2_dst.c b/trace2/tr2_dst.c
index fd490a43ad..7d96f33420 100644
--- a/trace2/tr2_dst.c
+++ b/trace2/tr2_dst.c
@@ -1,5 +1,6 @@
 #include "cache.h"
 #include "trace2/tr2_dst.h"
+#include "trace2/tr2_sysenv.h"
 
 /*
  * If a Trace2 target cannot be opened for writing, we should issue a
@@ -7,17 +8,13 @@
  * or socket and beyond the user's control -- especially since every
  * git command (and sub-command) will print the message.  So we silently
  * eat these warnings and just discard the trace data.
- *
- * Enable the following environment variable to see these warnings.
  */
-#define TR2_ENVVAR_DST_DEBUG "GIT_TR2_DST_DEBUG"
-
 static int tr2_dst_want_warning(void)
 {
 	static int tr2env_dst_debug = -1;
 
 	if (tr2env_dst_debug == -1) {
-		const char *env_value = getenv(TR2_ENVVAR_DST_DEBUG);
+		const char *env_value = tr2_sysenv_get(TR2_SYSENV_DST_DEBUG);
 		if (!env_value || !*env_value)
 			tr2env_dst_debug = 0;
 		else
@@ -42,7 +39,9 @@ static int tr2_dst_try_path(struct tr2_dst *dst, const char *tgt_value)
 	if (fd == -1) {
 		if (tr2_dst_want_warning())
 			warning("trace2: could not open '%s' for '%s' tracing: %s",
-				tgt_value, dst->env_var_name, strerror(errno));
+				tgt_value,
+				tr2_sysenv_display_name(dst->sysenv_var),
+				strerror(errno));
 
 		tr2_dst_trace_disable(dst);
 		return 0;
@@ -116,7 +115,8 @@ static int tr2_dst_try_unix_domain_socket(struct tr2_dst *dst,
 	if (!path || !*path) {
 		if (tr2_dst_want_warning())
 			warning("trace2: invalid AF_UNIX value '%s' for '%s' tracing",
-				tgt_value, dst->env_var_name);
+				tgt_value,
+				tr2_sysenv_display_name(dst->sysenv_var));
 
 		tr2_dst_trace_disable(dst);
 		return 0;
@@ -126,7 +126,7 @@ static int tr2_dst_try_unix_domain_socket(struct tr2_dst *dst,
 	    strlen(path) >= sizeof(((struct sockaddr_un *)0)->sun_path)) {
 		if (tr2_dst_want_warning())
 			warning("trace2: invalid AF_UNIX path '%s' for '%s' tracing",
-				path, dst->env_var_name);
+				path, tr2_sysenv_display_name(dst->sysenv_var));
 
 		tr2_dst_trace_disable(dst);
 		return 0;
@@ -148,7 +148,8 @@ static int tr2_dst_try_unix_domain_socket(struct tr2_dst *dst,
 error:
 	if (tr2_dst_want_warning())
 		warning("trace2: could not connect to socket '%s' for '%s' tracing: %s",
-			path, dst->env_var_name, strerror(e));
+			path, tr2_sysenv_display_name(dst->sysenv_var),
+			strerror(e));
 
 	tr2_dst_trace_disable(dst);
 	return 0;
@@ -168,7 +169,7 @@ static void tr2_dst_malformed_warning(struct tr2_dst *dst,
 	struct strbuf buf = STRBUF_INIT;
 
 	strbuf_addf(&buf, "trace2: unknown value for '%s': '%s'",
-		    dst->env_var_name, tgt_value);
+		    tr2_sysenv_display_name(dst->sysenv_var), tgt_value);
 	warning("%s", buf.buf);
 
 	strbuf_release(&buf);
@@ -184,7 +185,7 @@ int tr2_dst_get_trace_fd(struct tr2_dst *dst)
 
 	dst->initialized = 1;
 
-	tgt_value = getenv(dst->env_var_name);
+	tgt_value = tr2_sysenv_get(dst->sysenv_var);
 
 	if (!tgt_value || !strcmp(tgt_value, "") || !strcmp(tgt_value, "0") ||
 	    !strcasecmp(tgt_value, "false")) {
@@ -246,7 +247,8 @@ void tr2_dst_write_line(struct tr2_dst *dst, struct strbuf *buf_line)
 		return;
 
 	if (tr2_dst_want_warning())
-		warning("unable to write trace to '%s': %s", dst->env_var_name,
+		warning("unable to write trace to '%s': %s",
+			tr2_sysenv_display_name(dst->sysenv_var),
 			strerror(errno));
 	tr2_dst_trace_disable(dst);
 }
diff --git a/trace2/tr2_dst.h b/trace2/tr2_dst.h
index 9a64f05b02..3adf3bac13 100644
--- a/trace2/tr2_dst.h
+++ b/trace2/tr2_dst.h
@@ -2,9 +2,10 @@
 #define TR2_DST_H
 
 struct strbuf;
+#include "trace2/tr2_sysenv.h"
 
 struct tr2_dst {
-	const char *const env_var_name;
+	enum tr2_sysenv_variable sysenv_var;
 	int fd;
 	unsigned int initialized : 1;
 	unsigned int need_close : 1;
diff --git a/trace2/tr2_sysenv.c b/trace2/tr2_sysenv.c
new file mode 100644
index 0000000000..9025b86303
--- /dev/null
+++ b/trace2/tr2_sysenv.c
@@ -0,0 +1,127 @@
+#include "cache.h"
+#include "config.h"
+#include "dir.h"
+#include "tr2_sysenv.h"
+
+/*
+ * Each entry represents a trace2 setting.
+ * See Documentation/technical/api-trace2.txt
+ */
+struct tr2_sysenv_entry {
+	const char *env_var_name;
+	const char *git_config_name;
+
+	char *value;
+	unsigned int getenv_called : 1;
+};
+
+/*
+ * This table must match "enum tr2_sysenv_variable" in tr2_sysenv.h.
+ *
+ * The strings in this table are constant and must match the published
+ * config and environment variable names as described in the documentation.
+ *
+ * We do not define entries for the GIT_TR2_PARENT_* environment
+ * variables because they are transient and used to pass information
+ * from parent to child git processes, rather than settings.
+ */
+/* clang-format off */
+static struct tr2_sysenv_entry tr2_sysenv_settings[] = {
+	[TR2_SYSENV_CFG_PARAM]     = { "GIT_TR2_CONFIG_PARAMS",
+				       "trace2.configparams" },
+
+	[TR2_SYSENV_DST_DEBUG]     = { "GIT_TR2_DST_DEBUG",
+				       "trace2.destinationdebug" },
+
+	[TR2_SYSENV_NORMAL]        = { "GIT_TR2",
+				       "trace2.normaltarget" },
+	[TR2_SYSENV_NORMAL_BRIEF]  = { "GIT_TR2_BRIEF",
+				       "trace2.normalbrief" },
+
+	[TR2_SYSENV_EVENT]         = { "GIT_TR2_EVENT",
+				       "trace2.eventtarget" },
+	[TR2_SYSENV_EVENT_BRIEF]   = { "GIT_TR2_EVENT_BRIEF",
+				       "trace2.eventbrief" },
+	[TR2_SYSENV_EVENT_NESTING] = { "GIT_TR2_EVENT_NESTING",
+				       "trace2.eventnesting" },
+
+	[TR2_SYSENV_PERF]          = { "GIT_TR2_PERF",
+				       "trace2.perftarget" },
+	[TR2_SYSENV_PERF_BRIEF]    = { "GIT_TR2_PERF_BRIEF",
+				       "trace2.perfbrief" },
+};
+/* clang-format on */
+
+static int tr2_sysenv_cb(const char *key, const char *value, void *d)
+{
+	int k;
+
+	if (!starts_with(key, "trace2."))
+		return 0;
+
+	for (k = 0; k < ARRAY_SIZE(tr2_sysenv_settings); k++) {
+		if (!strcmp(key, tr2_sysenv_settings[k].git_config_name)) {
+			free(tr2_sysenv_settings[k].value);
+			tr2_sysenv_settings[k].value = xstrdup(value);
+			return 0;
+		}
+	}
+
+	return 0;
+}
+
+/*
+ * Load Trace2 settings from the system config (usually "/etc/gitconfig"
+ * unless we were built with a runtime-prefix).  These are intended to
+ * define the default values for Trace2 as requested by the administrator.
+ *
+ * Then override with the Trace2 settings from the global config.
+ */
+void tr2_sysenv_load(void)
+{
+	if (ARRAY_SIZE(tr2_sysenv_settings) != TR2_SYSENV_MUST_BE_LAST)
+		BUG("tr2_sysenv_settings size is wrong");
+
+	read_very_early_config(tr2_sysenv_cb, NULL);
+}
+
+/*
+ * Return the value for the requested Trace2 setting from these sources:
+ * the system config, the global config, and the environment.
+ */
+const char *tr2_sysenv_get(enum tr2_sysenv_variable var)
+{
+	if (var >= TR2_SYSENV_MUST_BE_LAST)
+		BUG("tr2_sysenv_get invalid var '%d'", var);
+
+	if (!tr2_sysenv_settings[var].getenv_called) {
+		const char *v = getenv(tr2_sysenv_settings[var].env_var_name);
+		if (v && *v) {
+			free(tr2_sysenv_settings[var].value);
+			tr2_sysenv_settings[var].value = xstrdup(v);
+		}
+		tr2_sysenv_settings[var].getenv_called = 1;
+	}
+
+	return tr2_sysenv_settings[var].value;
+}
+
+/*
+ * Return a friendly name for this setting that is suitable for printing
+ * in an error messages.
+ */
+const char *tr2_sysenv_display_name(enum tr2_sysenv_variable var)
+{
+	if (var >= TR2_SYSENV_MUST_BE_LAST)
+		BUG("tr2_sysenv_get invalid var '%d'", var);
+
+	return tr2_sysenv_settings[var].env_var_name;
+}
+
+void tr2_sysenv_release(void)
+{
+	int k;
+
+	for (k = 0; k < ARRAY_SIZE(tr2_sysenv_settings); k++)
+		free(tr2_sysenv_settings[k].value);
+}
diff --git a/trace2/tr2_sysenv.h b/trace2/tr2_sysenv.h
new file mode 100644
index 0000000000..369b20bd87
--- /dev/null
+++ b/trace2/tr2_sysenv.h
@@ -0,0 +1,36 @@
+#ifndef TR2_SYSENV_H
+#define TR2_SYSENV_H
+
+/*
+ * The Trace2 settings that can be loaded from /etc/gitconfig
+ * and/or user environment variables.
+ *
+ * Note that this set does not contain any of the transient
+ * environment variables used to pass information from parent
+ * to child git processes, such "GIT_TR2_PARENT_SID".
+ */
+enum tr2_sysenv_variable {
+	TR2_SYSENV_CFG_PARAM = 0,
+
+	TR2_SYSENV_DST_DEBUG,
+
+	TR2_SYSENV_NORMAL,
+	TR2_SYSENV_NORMAL_BRIEF,
+
+	TR2_SYSENV_EVENT,
+	TR2_SYSENV_EVENT_BRIEF,
+	TR2_SYSENV_EVENT_NESTING,
+
+	TR2_SYSENV_PERF,
+	TR2_SYSENV_PERF_BRIEF,
+
+	TR2_SYSENV_MUST_BE_LAST
+};
+
+void tr2_sysenv_load(void);
+
+const char *tr2_sysenv_get(enum tr2_sysenv_variable);
+const char *tr2_sysenv_display_name(enum tr2_sysenv_variable var);
+void tr2_sysenv_release(void);
+
+#endif /* TR2_SYSENV_H */
diff --git a/trace2/tr2_tgt_event.c b/trace2/tr2_tgt_event.c
index 89a4d3ae9a..48d9193b2c 100644
--- a/trace2/tr2_tgt_event.c
+++ b/trace2/tr2_tgt_event.c
@@ -6,10 +6,11 @@
 #include "trace2/tr2_dst.h"
 #include "trace2/tr2_tbuf.h"
 #include "trace2/tr2_sid.h"
+#include "trace2/tr2_sysenv.h"
 #include "trace2/tr2_tgt.h"
 #include "trace2/tr2_tls.h"
 
-static struct tr2_dst tr2dst_event = { "GIT_TR2_EVENT", 0, 0, 0 };
+static struct tr2_dst tr2dst_event = { TR2_SYSENV_EVENT, 0, 0, 0 };
 
 /*
  * The version number of the JSON data generated by the EVENT target
@@ -28,37 +29,36 @@ static struct tr2_dst tr2dst_event = { "GIT_TR2_EVENT", 0, 0, 0 };
  * are primarily intended for the performance target during debugging.
  *
  * Some of the outer-most messages, however, may be of interest to the
- * event target.  Set this environment variable to a larger integer for
- * more detail in the event target.
+ * event target.  Use the TR2_SYSENV_EVENT_NESTING setting to increase
+ * region details in the event target.
  */
-#define TR2_ENVVAR_EVENT_NESTING "GIT_TR2_EVENT_NESTING"
-static int tr2env_event_nesting_wanted = 2;
+static int tr2env_event_max_nesting_levels = 2;
 
 /*
- * Set this environment variable to true to omit the <time>, <file>, and
+ * Use the TR2_SYSENV_EVENT_BRIEF to omit the <time>, <file>, and
  * <line> fields from most events.
  */
-#define TR2_ENVVAR_EVENT_BRIEF "GIT_TR2_EVENT_BRIEF"
-static int tr2env_event_brief;
+static int tr2env_event_be_brief;
 
 static int fn_init(void)
 {
 	int want = tr2_dst_trace_want(&tr2dst_event);
-	int want_nesting;
+	int max_nesting;
 	int want_brief;
-	char *nesting;
-	char *brief;
+	const char *nesting;
+	const char *brief;
 
 	if (!want)
 		return want;
 
-	nesting = getenv(TR2_ENVVAR_EVENT_NESTING);
-	if (nesting && ((want_nesting = atoi(nesting)) > 0))
-		tr2env_event_nesting_wanted = want_nesting;
+	nesting = tr2_sysenv_get(TR2_SYSENV_EVENT_NESTING);
+	if (nesting && *nesting && ((max_nesting = atoi(nesting)) > 0))
+		tr2env_event_max_nesting_levels = max_nesting;
 
-	brief = getenv(TR2_ENVVAR_EVENT_BRIEF);
-	if (brief && ((want_brief = atoi(brief)) > 0))
-		tr2env_event_brief = want_brief;
+	brief = tr2_sysenv_get(TR2_SYSENV_EVENT_BRIEF);
+	if (brief && *brief &&
+	    ((want_brief = git_parse_maybe_bool(brief)) != -1))
+		tr2env_event_be_brief = want_brief;
 
 	return want;
 }
@@ -92,13 +92,13 @@ static void event_fmt_prepare(const char *event_name, const char *file,
 	/*
 	 * In brief mode, only emit <time> on these 2 event types.
 	 */
-	if (!tr2env_event_brief || !strcmp(event_name, "version") ||
+	if (!tr2env_event_be_brief || !strcmp(event_name, "version") ||
 	    !strcmp(event_name, "atexit")) {
 		tr2_tbuf_utc_time(&tb_now);
 		jw_object_string(jw, "time", tb_now.buf);
 	}
 
-	if (!tr2env_event_brief && file && *file) {
+	if (!tr2env_event_be_brief && file && *file) {
 		jw_object_string(jw, "file", file);
 		jw_object_intmax(jw, "line", line);
 	}
@@ -459,7 +459,7 @@ static void fn_region_enter_printf_va_fl(const char *file, int line,
 {
 	const char *event_name = "region_enter";
 	struct tr2tls_thread_ctx *ctx = tr2tls_get_self();
-	if (ctx->nr_open_regions <= tr2env_event_nesting_wanted) {
+	if (ctx->nr_open_regions <= tr2env_event_max_nesting_levels) {
 		struct json_writer jw = JSON_WRITER_INIT;
 
 		jw_object_begin(&jw, 0);
@@ -484,7 +484,7 @@ static void fn_region_leave_printf_va_fl(
 {
 	const char *event_name = "region_leave";
 	struct tr2tls_thread_ctx *ctx = tr2tls_get_self();
-	if (ctx->nr_open_regions <= tr2env_event_nesting_wanted) {
+	if (ctx->nr_open_regions <= tr2env_event_max_nesting_levels) {
 		struct json_writer jw = JSON_WRITER_INIT;
 		double t_rel = (double)us_elapsed_region / 1000000.0;
 
@@ -511,7 +511,7 @@ static void fn_data_fl(const char *file, int line, uint64_t us_elapsed_absolute,
 {
 	const char *event_name = "data";
 	struct tr2tls_thread_ctx *ctx = tr2tls_get_self();
-	if (ctx->nr_open_regions <= tr2env_event_nesting_wanted) {
+	if (ctx->nr_open_regions <= tr2env_event_max_nesting_levels) {
 		struct json_writer jw = JSON_WRITER_INIT;
 		double t_abs = (double)us_elapsed_absolute / 1000000.0;
 		double t_rel = (double)us_elapsed_region / 1000000.0;
@@ -539,7 +539,7 @@ static void fn_data_json_fl(const char *file, int line,
 {
 	const char *event_name = "data_json";
 	struct tr2tls_thread_ctx *ctx = tr2tls_get_self();
-	if (ctx->nr_open_regions <= tr2env_event_nesting_wanted) {
+	if (ctx->nr_open_regions <= tr2env_event_max_nesting_levels) {
 		struct json_writer jw = JSON_WRITER_INIT;
 		double t_abs = (double)us_elapsed_absolute / 1000000.0;
 		double t_rel = (double)us_elapsed_region / 1000000.0;
diff --git a/trace2/tr2_tgt_normal.c b/trace2/tr2_tgt_normal.c
index 57f3e18f5b..1ce6f97863 100644
--- a/trace2/tr2_tgt_normal.c
+++ b/trace2/tr2_tgt_normal.c
@@ -4,20 +4,20 @@
 #include "quote.h"
 #include "version.h"
 #include "trace2/tr2_dst.h"
+#include "trace2/tr2_sysenv.h"
 #include "trace2/tr2_tbuf.h"
 #include "trace2/tr2_tgt.h"
 #include "trace2/tr2_tls.h"
 
-static struct tr2_dst tr2dst_normal = { "GIT_TR2", 0, 0, 0 };
+static struct tr2_dst tr2dst_normal = { TR2_SYSENV_NORMAL, 0, 0, 0 };
 
 /*
- * Set this environment variable to true to omit the "<time> <file>:<line>"
+ * Use the TR2_SYSENV_NORMAL_BRIEF setting to omit the "<time> <file>:<line>"
  * fields from each line written to the builtin normal target.
  *
  * Unit tests may want to use this to help with testing.
  */
-#define TR2_ENVVAR_NORMAL_BRIEF "GIT_TR2_BRIEF"
-static int tr2env_normal_brief;
+static int tr2env_normal_be_brief;
 
 #define TR2FMT_NORMAL_FL_WIDTH (50)
 
@@ -25,15 +25,15 @@ static int fn_init(void)
 {
 	int want = tr2_dst_trace_want(&tr2dst_normal);
 	int want_brief;
-	char *brief;
+	const char *brief;
 
 	if (!want)
 		return want;
 
-	brief = getenv(TR2_ENVVAR_NORMAL_BRIEF);
+	brief = tr2_sysenv_get(TR2_SYSENV_NORMAL_BRIEF);
 	if (brief && *brief &&
 	    ((want_brief = git_parse_maybe_bool(brief)) != -1))
-		tr2env_normal_brief = want_brief;
+		tr2env_normal_be_brief = want_brief;
 
 	return want;
 }
@@ -47,7 +47,7 @@ static void normal_fmt_prepare(const char *file, int line, struct strbuf *buf)
 {
 	strbuf_setlen(buf, 0);
 
-	if (!tr2env_normal_brief) {
+	if (!tr2env_normal_be_brief) {
 		struct tr2_tbuf tb_now;
 
 		tr2_tbuf_local_time(&tb_now);
diff --git a/trace2/tr2_tgt_perf.c b/trace2/tr2_tgt_perf.c
index 9c3b4d8a0f..328d2234bd 100644
--- a/trace2/tr2_tgt_perf.c
+++ b/trace2/tr2_tgt_perf.c
@@ -6,20 +6,20 @@
 #include "json-writer.h"
 #include "trace2/tr2_dst.h"
 #include "trace2/tr2_sid.h"
+#include "trace2/tr2_sysenv.h"
 #include "trace2/tr2_tbuf.h"
 #include "trace2/tr2_tgt.h"
 #include "trace2/tr2_tls.h"
 
-static struct tr2_dst tr2dst_perf = { "GIT_TR2_PERF", 0, 0, 0 };
+static struct tr2_dst tr2dst_perf = { TR2_SYSENV_PERF, 0, 0, 0 };
 
 /*
- * Set this environment variable to true to omit the "<time> <file>:<line>"
+ * Use TR2_SYSENV_PERF_BRIEF to omit the "<time> <file>:<line>"
  * fields from each line written to the builtin performance target.
  *
  * Unit tests may want to use this to help with testing.
  */
-#define TR2_ENVVAR_PERF_BRIEF "GIT_TR2_PERF_BRIEF"
-static int tr2env_perf_brief;
+static int tr2env_perf_be_brief;
 
 #define TR2FMT_PERF_FL_WIDTH (50)
 #define TR2FMT_PERF_MAX_EVENT_NAME (12)
@@ -36,17 +36,17 @@ static int fn_init(void)
 {
 	int want = tr2_dst_trace_want(&tr2dst_perf);
 	int want_brief;
-	char *brief;
+	const char *brief;
 
 	if (!want)
 		return want;
 
 	strbuf_addchars(&dots, '.', TR2_DOTS_BUFFER_SIZE);
 
-	brief = getenv(TR2_ENVVAR_PERF_BRIEF);
+	brief = tr2_sysenv_get(TR2_SYSENV_PERF_BRIEF);
 	if (brief && *brief &&
 	    ((want_brief = git_parse_maybe_bool(brief)) != -1))
-		tr2env_perf_brief = want_brief;
+		tr2env_perf_be_brief = want_brief;
 
 	return want;
 }
@@ -77,7 +77,7 @@ static void perf_fmt_prepare(const char *event_name,
 
 	strbuf_setlen(buf, 0);
 
-	if (!tr2env_perf_brief) {
+	if (!tr2env_perf_be_brief) {
 		struct tr2_tbuf tb_now;
 
 		tr2_tbuf_local_time(&tb_now);
-- 
gitgitgadget


^ permalink raw reply	[flat|nested] 68+ messages in thread

* [PATCH v5 07/11] trace2: report peak memory usage of the process
  2019-04-29 20:14       ` [PATCH v5 00/11] trace2: load trace2 settings from system config Jeff Hostetler via GitGitGadget
                           ` (5 preceding siblings ...)
  2019-04-29 20:14         ` [PATCH v5 06/11] trace2: use system/global config for default trace2 settings Jeff Hostetler via GitGitGadget
@ 2019-04-29 20:14         ` Jeff Hostetler via GitGitGadget
  2019-04-29 20:14         ` [PATCH v5 09/11] trace2: make SIDs more unique Jeff Hostetler via GitGitGadget
                           ` (4 subsequent siblings)
  11 siblings, 0 replies; 68+ messages in thread
From: Jeff Hostetler via GitGitGadget @ 2019-04-29 20:14 UTC (permalink / raw)
  To: git
  Cc: gitster, peff, jrnieder, steadmon, avarab, Junio C Hamano,
	Jeff Hostetler

From: Jeff Hostetler <jeffhost@microsoft.com>

Teach Windows version of git to report peak memory usage
during exit() processing.

Signed-off-by: Jeff Hostetler <jeffhost@microsoft.com>
---
 common-main.c                            |  2 +-
 compat/win32/trace2_win32_process_info.c | 50 ++++++++++++++++++++++--
 trace2.c                                 |  2 +
 trace2.h                                 | 14 +++++--
 4 files changed, 60 insertions(+), 8 deletions(-)

diff --git a/common-main.c b/common-main.c
index 299ca62a72..582a7b1886 100644
--- a/common-main.c
+++ b/common-main.c
@@ -41,7 +41,7 @@ int main(int argc, const char **argv)
 
 	trace2_initialize();
 	trace2_cmd_start(argv);
-	trace2_collect_process_info();
+	trace2_collect_process_info(TRACE2_PROCESS_INFO_STARTUP);
 
 	git_setup_gettext();
 
diff --git a/compat/win32/trace2_win32_process_info.c b/compat/win32/trace2_win32_process_info.c
index 52bd62034b..8ccbd1c2c6 100644
--- a/compat/win32/trace2_win32_process_info.c
+++ b/compat/win32/trace2_win32_process_info.c
@@ -1,5 +1,6 @@
 #include "../../cache.h"
 #include "../../json-writer.h"
+#include "lazyload.h"
 #include <Psapi.h>
 #include <tlHelp32.h>
 
@@ -137,11 +138,54 @@ static void get_is_being_debugged(void)
 				   "windows/debugger_present", 1);
 }
 
-void trace2_collect_process_info(void)
+/*
+ * Emit JSON data with the peak memory usage of the current process.
+ */
+static void get_peak_memory_info(void)
+{
+	DECLARE_PROC_ADDR(psapi.dll, BOOL, GetProcessMemoryInfo, HANDLE,
+			  PPROCESS_MEMORY_COUNTERS, DWORD);
+
+	if (INIT_PROC_ADDR(GetProcessMemoryInfo)) {
+		PROCESS_MEMORY_COUNTERS pmc;
+
+		if (GetProcessMemoryInfo(GetCurrentProcess(), &pmc,
+					 sizeof(pmc))) {
+			struct json_writer jw = JSON_WRITER_INIT;
+
+			jw_object_begin(&jw, 0);
+
+#define KV(kv) #kv, (intmax_t)pmc.kv
+
+			jw_object_intmax(&jw, KV(PageFaultCount));
+			jw_object_intmax(&jw, KV(PeakWorkingSetSize));
+			jw_object_intmax(&jw, KV(PeakPagefileUsage));
+
+			jw_end(&jw);
+
+			trace2_data_json("process", the_repository,
+					 "windows/memory", &jw);
+			jw_release(&jw);
+		}
+	}
+}
+
+void trace2_collect_process_info(enum trace2_process_info_reason reason)
 {
 	if (!trace2_is_enabled())
 		return;
 
-	get_is_being_debugged();
-	get_ancestry();
+	switch (reason) {
+	case TRACE2_PROCESS_INFO_STARTUP:
+		get_is_being_debugged();
+		get_ancestry();
+		return;
+
+	case TRACE2_PROCESS_INFO_EXIT:
+		get_peak_memory_info();
+		return;
+
+	default:
+		BUG("trace2_collect_process_info: unknown reason '%d'", reason);
+	}
 }
diff --git a/trace2.c b/trace2.c
index 490b3f071e..6baa65cdf9 100644
--- a/trace2.c
+++ b/trace2.c
@@ -213,6 +213,8 @@ int trace2_cmd_exit_fl(const char *file, int line, int code)
 	if (!trace2_enabled)
 		return code;
 
+	trace2_collect_process_info(TRACE2_PROCESS_INFO_EXIT);
+
 	tr2main_exit_code = code;
 
 	us_now = getnanotime() / 1000;
diff --git a/trace2.h b/trace2.h
index 894bfca7e0..888531eb08 100644
--- a/trace2.h
+++ b/trace2.h
@@ -391,13 +391,19 @@ void trace2_printf(const char *fmt, ...);
  * Optional platform-specific code to dump information about the
  * current and any parent process(es).  This is intended to allow
  * post-processors to know who spawned this git instance and anything
- * else the platform may be able to tell us about the current process.
+ * else that the platform may be able to tell us about the current process.
  */
+
+enum trace2_process_info_reason {
+	TRACE2_PROCESS_INFO_STARTUP,
+	TRACE2_PROCESS_INFO_EXIT,
+};
+
 #if defined(GIT_WINDOWS_NATIVE)
-void trace2_collect_process_info(void);
+void trace2_collect_process_info(enum trace2_process_info_reason reason);
 #else
-#define trace2_collect_process_info() \
-	do {                          \
+#define trace2_collect_process_info(reason) \
+	do {                                \
 	} while (0)
 #endif
 
-- 
gitgitgadget


^ permalink raw reply	[flat|nested] 68+ messages in thread

* [PATCH v5 08/11] trace2: clarify UTC datetime formatting
  2019-04-29 20:14       ` [PATCH v5 00/11] trace2: load trace2 settings from system config Jeff Hostetler via GitGitGadget
                           ` (7 preceding siblings ...)
  2019-04-29 20:14         ` [PATCH v5 09/11] trace2: make SIDs more unique Jeff Hostetler via GitGitGadget
@ 2019-04-29 20:14         ` Jeff Hostetler via GitGitGadget
  2019-04-29 20:14         ` [PATCH v5 10/11] trace2: update docs to describe system/global config settings Jeff Hostetler via GitGitGadget
                           ` (2 subsequent siblings)
  11 siblings, 0 replies; 68+ messages in thread
From: Jeff Hostetler via GitGitGadget @ 2019-04-29 20:14 UTC (permalink / raw)
  To: git
  Cc: gitster, peff, jrnieder, steadmon, avarab, Junio C Hamano,
	Jeff Hostetler

From: Jeff Hostetler <jeffhost@microsoft.com>

Update tr2_tbuf_utc_datetime to generate extended UTC format.
Update tr2_tgt_event target to use extended format in 'time' columns.

Signed-off-by: Jeff Hostetler <jeffhost@microsoft.com>
---
 Documentation/technical/api-trace2.txt | 12 ++++++------
 trace2/tr2_tbuf.c                      |  4 ++--
 trace2/tr2_tbuf.h                      |  4 ++--
 trace2/tr2_tgt_event.c                 |  2 +-
 4 files changed, 11 insertions(+), 11 deletions(-)

diff --git a/Documentation/technical/api-trace2.txt b/Documentation/technical/api-trace2.txt
index baaa1153bb..cdc00bcc5d 100644
--- a/Documentation/technical/api-trace2.txt
+++ b/Documentation/technical/api-trace2.txt
@@ -78,11 +78,11 @@ git version 2.20.1.155.g426c96fcdb
 +
 ------------
 $ cat ~/log.event
-{"event":"version","sid":"1547659722619736-11614","thread":"main","time":"2019-01-16 17:28:42.620713","file":"common-main.c","line":38,"evt":"1","exe":"2.20.1.155.g426c96fcdb"}
-{"event":"start","sid":"1547659722619736-11614","thread":"main","time":"2019-01-16 17:28:42.621027","file":"common-main.c","line":39,"t_abs":0.001173,"argv":["git","version"]}
-{"event":"cmd_name","sid":"1547659722619736-11614","thread":"main","time":"2019-01-16 17:28:42.621122","file":"git.c","line":432,"name":"version","hierarchy":"version"}
-{"event":"exit","sid":"1547659722619736-11614","thread":"main","time":"2019-01-16 17:28:42.621236","file":"git.c","line":662,"t_abs":0.001227,"code":0}
-{"event":"atexit","sid":"1547659722619736-11614","thread":"main","time":"2019-01-16 17:28:42.621268","file":"trace2/tr2_tgt_event.c","line":163,"t_abs":0.001265,"code":0}
+{"event":"version","sid":"1547659722619736-11614","thread":"main","time":"2019-01-16T17:28:42.620713Z","file":"common-main.c","line":38,"evt":"1","exe":"2.20.1.155.g426c96fcdb"}
+{"event":"start","sid":"1547659722619736-11614","thread":"main","time":"2019-01-16T17:28:42.621027Z","file":"common-main.c","line":39,"t_abs":0.001173,"argv":["git","version"]}
+{"event":"cmd_name","sid":"1547659722619736-11614","thread":"main","time":"2019-01-16T17:28:42.621122Z","file":"git.c","line":432,"name":"version","hierarchy":"version"}
+{"event":"exit","sid":"1547659722619736-11614","thread":"main","time":"2019-01-16T17:28:42.621236Z","file":"git.c","line":662,"t_abs":0.001227,"code":0}
+{"event":"atexit","sid":"1547659722619736-11614","thread":"main","time":"2019-01-16T17:28:42.621268Z","file":"trace2/tr2_tgt_event.c","line":163,"t_abs":0.001265,"code":0}
 ------------
 
 == Enabling a Target
@@ -542,7 +542,7 @@ The following key/value pairs are common to all events:
 	"event":"version",
 	"sid":"1547659722619736-11614",
 	"thread":"main",
-	"time":"2019-01-16 17:28:42.620713",
+	"time":"2019-01-16T17:28:42.620713Z",
 	"file":"common-main.c",
 	"line":38,
 	...
diff --git a/trace2/tr2_tbuf.c b/trace2/tr2_tbuf.c
index 0844910423..eb1b240d8a 100644
--- a/trace2/tr2_tbuf.c
+++ b/trace2/tr2_tbuf.c
@@ -15,7 +15,7 @@ void tr2_tbuf_local_time(struct tr2_tbuf *tb)
 		  tm.tm_min, tm.tm_sec, (long)tv.tv_usec);
 }
 
-void tr2_tbuf_utc_time(struct tr2_tbuf *tb)
+void tr2_tbuf_utc_datetime_extended(struct tr2_tbuf *tb)
 {
 	struct timeval tv;
 	struct tm tm;
@@ -26,7 +26,7 @@ void tr2_tbuf_utc_time(struct tr2_tbuf *tb)
 	gmtime_r(&secs, &tm);
 
 	xsnprintf(tb->buf, sizeof(tb->buf),
-		  "%4d-%02d-%02d %02d:%02d:%02d.%06ld", tm.tm_year + 1900,
+		  "%4d-%02d-%02dT%02d:%02d:%02d.%06ldZ", tm.tm_year + 1900,
 		  tm.tm_mon + 1, tm.tm_mday, tm.tm_hour, tm.tm_min, tm.tm_sec,
 		  (long)tv.tv_usec);
 }
diff --git a/trace2/tr2_tbuf.h b/trace2/tr2_tbuf.h
index 9cdefa3957..2a1d173ff2 100644
--- a/trace2/tr2_tbuf.h
+++ b/trace2/tr2_tbuf.h
@@ -16,8 +16,8 @@ struct tr2_tbuf {
 void tr2_tbuf_local_time(struct tr2_tbuf *tb);
 
 /*
- * Fill buffer with formatted UTC time string.
+ * Fill buffer with formatted UTC datatime string.
  */
-void tr2_tbuf_utc_time(struct tr2_tbuf *tb);
+void tr2_tbuf_utc_datetime_extended(struct tr2_tbuf *tb);
 
 #endif /* TR2_TBUF_H */
diff --git a/trace2/tr2_tgt_event.c b/trace2/tr2_tgt_event.c
index 48d9193b2c..2c97cf54be 100644
--- a/trace2/tr2_tgt_event.c
+++ b/trace2/tr2_tgt_event.c
@@ -94,7 +94,7 @@ static void event_fmt_prepare(const char *event_name, const char *file,
 	 */
 	if (!tr2env_event_be_brief || !strcmp(event_name, "version") ||
 	    !strcmp(event_name, "atexit")) {
-		tr2_tbuf_utc_time(&tb_now);
+		tr2_tbuf_utc_datetime_extended(&tb_now);
 		jw_object_string(jw, "time", tb_now.buf);
 	}
 
-- 
gitgitgadget


^ permalink raw reply	[flat|nested] 68+ messages in thread

* [PATCH v5 09/11] trace2: make SIDs more unique
  2019-04-29 20:14       ` [PATCH v5 00/11] trace2: load trace2 settings from system config Jeff Hostetler via GitGitGadget
                           ` (6 preceding siblings ...)
  2019-04-29 20:14         ` [PATCH v5 07/11] trace2: report peak memory usage of the process Jeff Hostetler via GitGitGadget
@ 2019-04-29 20:14         ` Jeff Hostetler via GitGitGadget
  2019-04-29 20:14         ` [PATCH v5 08/11] trace2: clarify UTC datetime formatting Jeff Hostetler via GitGitGadget
                           ` (3 subsequent siblings)
  11 siblings, 0 replies; 68+ messages in thread
From: Jeff Hostetler via GitGitGadget @ 2019-04-29 20:14 UTC (permalink / raw)
  To: git
  Cc: gitster, peff, jrnieder, steadmon, avarab, Junio C Hamano,
	Jeff Hostetler

From: Jeff Hostetler <jeffhost@microsoft.com>

Update SID component construction to use the current UTC datetime
and a portion of the SHA1 of the hostname.

Use an simplified date/time format to make it easier to use the
SID component as a logfile filename.

Signed-off-by: Jeff Hostetler <jeffhost@microsoft.com>
---
 Documentation/technical/api-trace2.txt | 16 ++++----
 trace2/tr2_sid.c                       | 53 ++++++++++++++++++++++++--
 trace2/tr2_tbuf.c                      | 15 ++++++++
 trace2/tr2_tbuf.h                      |  1 +
 4 files changed, 73 insertions(+), 12 deletions(-)

diff --git a/Documentation/technical/api-trace2.txt b/Documentation/technical/api-trace2.txt
index cdc00bcc5d..43adbf00eb 100644
--- a/Documentation/technical/api-trace2.txt
+++ b/Documentation/technical/api-trace2.txt
@@ -78,11 +78,11 @@ git version 2.20.1.155.g426c96fcdb
 +
 ------------
 $ cat ~/log.event
-{"event":"version","sid":"1547659722619736-11614","thread":"main","time":"2019-01-16T17:28:42.620713Z","file":"common-main.c","line":38,"evt":"1","exe":"2.20.1.155.g426c96fcdb"}
-{"event":"start","sid":"1547659722619736-11614","thread":"main","time":"2019-01-16T17:28:42.621027Z","file":"common-main.c","line":39,"t_abs":0.001173,"argv":["git","version"]}
-{"event":"cmd_name","sid":"1547659722619736-11614","thread":"main","time":"2019-01-16T17:28:42.621122Z","file":"git.c","line":432,"name":"version","hierarchy":"version"}
-{"event":"exit","sid":"1547659722619736-11614","thread":"main","time":"2019-01-16T17:28:42.621236Z","file":"git.c","line":662,"t_abs":0.001227,"code":0}
-{"event":"atexit","sid":"1547659722619736-11614","thread":"main","time":"2019-01-16T17:28:42.621268Z","file":"trace2/tr2_tgt_event.c","line":163,"t_abs":0.001265,"code":0}
+{"event":"version","sid":"sid":"20190408T191610.507018Z-H9b68c35f-P028492","thread":"main","time":"2019-01-16T17:28:42.620713Z","file":"common-main.c","line":38,"evt":"1","exe":"2.20.1.155.g426c96fcdb"}
+{"event":"start","sid":"20190408T191610.507018Z-H9b68c35f-P028492","thread":"main","time":"2019-01-16T17:28:42.621027Z","file":"common-main.c","line":39,"t_abs":0.001173,"argv":["git","version"]}
+{"event":"cmd_name","sid":"20190408T191610.507018Z-H9b68c35f-P028492","thread":"main","time":"2019-01-16T17:28:42.621122Z","file":"git.c","line":432,"name":"version","hierarchy":"version"}
+{"event":"exit","sid":"20190408T191610.507018Z-H9b68c35f-P028492","thread":"main","time":"2019-01-16T17:28:42.621236Z","file":"git.c","line":662,"t_abs":0.001227,"code":0}
+{"event":"atexit","sid":"20190408T191610.507018Z-H9b68c35f-P028492","thread":"main","time":"2019-01-16T17:28:42.621268Z","file":"trace2/tr2_tgt_event.c","line":163,"t_abs":0.001265,"code":0}
 ------------
 
 == Enabling a Target
@@ -540,11 +540,11 @@ The following key/value pairs are common to all events:
 ------------
 {
 	"event":"version",
-	"sid":"1547659722619736-11614",
+	"sid":"20190408T191827.272759Z-H9b68c35f-P011764",
 	"thread":"main",
-	"time":"2019-01-16T17:28:42.620713Z",
+	"time":"2019-04-08T19:18:27.282761Z",
 	"file":"common-main.c",
-	"line":38,
+	"line":42,
 	...
 }
 ------------
diff --git a/trace2/tr2_sid.c b/trace2/tr2_sid.c
index 984524a43c..5047095478 100644
--- a/trace2/tr2_sid.c
+++ b/trace2/tr2_sid.c
@@ -1,4 +1,5 @@
 #include "cache.h"
+#include "trace2/tr2_tbuf.h"
 #include "trace2/tr2_sid.h"
 
 #define TR2_ENVVAR_PARENT_SID "GIT_TR2_PARENT_SID"
@@ -6,6 +7,53 @@
 static struct strbuf tr2sid_buf = STRBUF_INIT;
 static int tr2sid_nr_git_parents;
 
+/*
+ * Compute the final component of the SID representing the current process.
+ * This should uniquely identify the process and be a valid filename (to
+ * allow writing trace2 data to per-process files).  It should also be fixed
+ * length for possible use as a database key.
+ *
+ * "<yyyymmdd>T<hhmmss>.<fraction>Z-<host>-<process>"
+ *
+ * where <host> is a 9 character string:
+ *    "H<first_8_chars_of_sha1_of_hostname>"
+ *    "Localhost" when no hostname.
+ *
+ * where <process> is a 9 character string containing the least signifcant
+ * 32 bits in the process-id.
+ *    "P<pid>"
+ * (This is an abribrary choice.  On most systems pid_t is a 32 bit value,
+ * so limit doesn't matter.  On larger systems, a truncated value is fine
+ * for our purposes here.)
+ */
+static void tr2_sid_append_my_sid_component(void)
+{
+	const struct git_hash_algo *algo = &hash_algos[GIT_HASH_SHA1];
+	struct tr2_tbuf tb_now;
+	git_hash_ctx ctx;
+	pid_t pid = getpid();
+	unsigned char hash[GIT_MAX_RAWSZ + 1];
+	char hex[GIT_MAX_HEXSZ + 1];
+	char hostname[HOST_NAME_MAX + 1];
+
+	tr2_tbuf_utc_datetime(&tb_now);
+	strbuf_addstr(&tr2sid_buf, tb_now.buf);
+
+	strbuf_addch(&tr2sid_buf, '-');
+	if (xgethostname(hostname, sizeof(hostname)))
+		strbuf_add(&tr2sid_buf, "Localhost", 9);
+	else {
+		algo->init_fn(&ctx);
+		algo->update_fn(&ctx, hostname, strlen(hostname));
+		algo->final_fn(hash, &ctx);
+		hash_to_hex_algop_r(hex, hash, algo);
+		strbuf_addch(&tr2sid_buf, 'H');
+		strbuf_add(&tr2sid_buf, hex, 8);
+	}
+
+	strbuf_addf(&tr2sid_buf, "-P%08"PRIx32, (uint32_t)pid);
+}
+
 /*
  * Compute a "unique" session id (SID) for the current process.  This allows
  * all events from this process to have a single label (much like a PID).
@@ -20,7 +68,6 @@ static int tr2sid_nr_git_parents;
  */
 static void tr2_sid_compute(void)
 {
-	uint64_t us_now;
 	const char *parent_sid;
 
 	if (tr2sid_buf.len)
@@ -38,9 +85,7 @@ static void tr2_sid_compute(void)
 		tr2sid_nr_git_parents++;
 	}
 
-	us_now = getnanotime() / 1000;
-	strbuf_addf(&tr2sid_buf, "%" PRIuMAX "-%" PRIdMAX, (uintmax_t)us_now,
-		    (intmax_t)getpid());
+	tr2_sid_append_my_sid_component();
 
 	setenv(TR2_ENVVAR_PARENT_SID, tr2sid_buf.buf, 1);
 }
diff --git a/trace2/tr2_tbuf.c b/trace2/tr2_tbuf.c
index eb1b240d8a..2498482d9a 100644
--- a/trace2/tr2_tbuf.c
+++ b/trace2/tr2_tbuf.c
@@ -30,3 +30,18 @@ void tr2_tbuf_utc_datetime_extended(struct tr2_tbuf *tb)
 		  tm.tm_mon + 1, tm.tm_mday, tm.tm_hour, tm.tm_min, tm.tm_sec,
 		  (long)tv.tv_usec);
 }
+
+void tr2_tbuf_utc_datetime(struct tr2_tbuf *tb)
+{
+	struct timeval tv;
+	struct tm tm;
+	time_t secs;
+
+	gettimeofday(&tv, NULL);
+	secs = tv.tv_sec;
+	gmtime_r(&secs, &tm);
+
+	xsnprintf(tb->buf, sizeof(tb->buf), "%4d%02d%02dT%02d%02d%02d.%06ldZ",
+		  tm.tm_year + 1900, tm.tm_mon + 1, tm.tm_mday, tm.tm_hour,
+		  tm.tm_min, tm.tm_sec, (long)tv.tv_usec);
+}
diff --git a/trace2/tr2_tbuf.h b/trace2/tr2_tbuf.h
index 2a1d173ff2..fa853d8f42 100644
--- a/trace2/tr2_tbuf.h
+++ b/trace2/tr2_tbuf.h
@@ -19,5 +19,6 @@ void tr2_tbuf_local_time(struct tr2_tbuf *tb);
  * Fill buffer with formatted UTC datatime string.
  */
 void tr2_tbuf_utc_datetime_extended(struct tr2_tbuf *tb);
+void tr2_tbuf_utc_datetime(struct tr2_tbuf *tb);
 
 #endif /* TR2_TBUF_H */
-- 
gitgitgadget


^ permalink raw reply	[flat|nested] 68+ messages in thread

* [PATCH v5 10/11] trace2: update docs to describe system/global config settings
  2019-04-29 20:14       ` [PATCH v5 00/11] trace2: load trace2 settings from system config Jeff Hostetler via GitGitGadget
                           ` (8 preceding siblings ...)
  2019-04-29 20:14         ` [PATCH v5 08/11] trace2: clarify UTC datetime formatting Jeff Hostetler via GitGitGadget
@ 2019-04-29 20:14         ` Jeff Hostetler via GitGitGadget
  2019-04-29 20:14         ` [PATCH v5 11/11] trace2: fixup access problem on /etc/gitconfig in read_very_early_config Jeff Hostetler via GitGitGadget
  2019-04-29 20:21         ` [PATCH v5 00/11] trace2: load trace2 settings from system config Jeff Hostetler
  11 siblings, 0 replies; 68+ messages in thread
From: Jeff Hostetler via GitGitGadget @ 2019-04-29 20:14 UTC (permalink / raw)
  To: git
  Cc: gitster, peff, jrnieder, steadmon, avarab, Junio C Hamano,
	Jeff Hostetler

From: Jeff Hostetler <jeffhost@microsoft.com>

Signed-off-by: Jeff Hostetler <jeffhost@microsoft.com>
---
 Documentation/config.txt               |   2 +
 Documentation/config/trace2.txt        |  56 +++++++++
 Documentation/technical/api-trace2.txt | 151 ++++++++++++++-----------
 Documentation/trace2-target-values.txt |  10 ++
 4 files changed, 152 insertions(+), 67 deletions(-)
 create mode 100644 Documentation/config/trace2.txt
 create mode 100644 Documentation/trace2-target-values.txt

diff --git a/Documentation/config.txt b/Documentation/config.txt
index d87846faa6..7e2a6f61f5 100644
--- a/Documentation/config.txt
+++ b/Documentation/config.txt
@@ -422,6 +422,8 @@ include::config/submodule.txt[]
 
 include::config/tag.txt[]
 
+include::config/trace2.txt[]
+
 include::config/transfer.txt[]
 
 include::config/uploadarchive.txt[]
diff --git a/Documentation/config/trace2.txt b/Documentation/config/trace2.txt
new file mode 100644
index 0000000000..a5f409c1c1
--- /dev/null
+++ b/Documentation/config/trace2.txt
@@ -0,0 +1,56 @@
+Trace2 config settings are only read from the system and global
+config files; repository local and worktree config files and `-c`
+command line arguments are not respected.
+
+trace2.normalTarget::
+	This variable controls the normal target destination.
+	It may be overridden by the `GIT_TR2` environment variable.
+	The following table shows possible values.
+
+trace2.perfTarget::
+	This variable controls the performance target destination.
+	It may be overridden by the `GIT_TR2_PERF` environment variable.
+	The following table shows possible values.
+
+trace2.eventTarget::
+	This variable controls the event target destination.
+	It may be overridden by the `GIT_TR2_EVENT` environment variable.
+	The following table shows possible values.
++
+include::../trace2-target-values.txt[]
+
+trace2.normalBrief::
+	Boolean.  When true `time`, `filename`, and `line` fields are
+	omitted from normal output.  May be overridden by the
+	`GIT_TR2_BRIEF` environment variable.  Defaults to false.
+
+trace2.perfBrief::
+	Boolean.  When true `time`, `filename`, and `line` fields are
+	omitted from PERF output.  May be overridden by the
+	`GIT_TR2_PERF_BRIEF` environment variable.  Defaults to false.
+
+trace2.eventBrief::
+	Boolean.  When true `time`, `filename`, and `line` fields are
+	omitted from event output.  May be overridden by the
+	`GIT_TR2_EVENT_BRIEF` environment variable.  Defaults to false.
+
+trace2.eventNesting::
+	Integer.  Specifies desired depth of nested regions in the
+	event output.  Regions deeper than this value will be
+	omitted.  May be overridden by the `GIT_TR2_EVENT_NESTING`
+	environment variable.  Defaults to 2.
+
+trace2.configParams::
+	A comma-separated list of patterns of "important" config
+	settings that should be recorded in the trace2 output.
+	For example, `core.*,remote.*.url` would cause the trace2
+	output to contain events listing each configured remote.
+	May be overridden by the `GIT_TR2_CONFIG_PARAMS` environment
+	variable.  Unset by default.
+
+trace2.destinationDebug::
+	Boolean.  When true Git will print error messages when a
+	trace target destination cannot be opened for writing.
+	By default, these errors are suppressed and tracing is
+	silently disabled.  May be overridden by the
+	`GIT_TR2_DST_DEBUG` environment variable.
diff --git a/Documentation/technical/api-trace2.txt b/Documentation/technical/api-trace2.txt
index 43adbf00eb..8b6a5e6d4b 100644
--- a/Documentation/technical/api-trace2.txt
+++ b/Documentation/technical/api-trace2.txt
@@ -22,21 +22,41 @@ Targets are defined using a VTable allowing easy extension to other
 formats in the future.  This might be used to define a binary format,
 for example.
 
+Trace2 is controlled using `trace2.*` config values in the system and
+global config files and `GIT_TR2*` environment variables.  Trace2 does
+not read from repo local or worktree config files or respect `-c`
+command line config settings.
+
 == Trace2 Targets
 
 Trace2 defines the following set of Trace2 Targets.
 Format details are given in a later section.
 
-`GIT_TR2` (NORMAL)::
+=== The Normal Format Target
+
+The normal format target is a tradition printf format and similar
+to GIT_TRACE format.  This format is enabled with the `GIT_TR`
+environment variable or the `trace2.normalTarget` system or global
+config setting.
+
+For example
 
-	a simple printf format like GIT_TRACE.
-+
 ------------
 $ export GIT_TR2=~/log.normal
 $ git version
 git version 2.20.1.155.g426c96fcdb
 ------------
-+
+
+or
+
+------------
+$ git config --global trace2.normalTarget ~/log.normal
+$ git version
+git version 2.20.1.155.g426c96fcdb
+------------
+
+yields
+
 ------------
 $ cat ~/log.normal
 12:28:42.620009 common-main.c:38                  version 2.20.1.155.g426c96fcdb
@@ -46,17 +66,32 @@ $ cat ~/log.normal
 12:28:42.621250 trace2/tr2_tgt_normal.c:124       atexit elapsed:0.001265 code:0
 ------------
 
-`GIT_TR2_PERF` (PERF)::
+=== The Performance Format Target
+
+The performance format target (PERF) is a column-based format to
+replace GIT_TRACE_PERFORMANCE and is suitable for development and
+testing, possibly to complement tools like gprof.  This format is
+enabled with the `GIT_TR2_PERF` environment variable or the
+`trace2.perfTarget` system or global config setting.
+
+For example
 
-	a column-based format to replace GIT_TRACE_PERFORMANCE suitable for
-	development and testing, possibly to complement tools like gprof.
-+
 ------------
 $ export GIT_TR2_PERF=~/log.perf
 $ git version
 git version 2.20.1.155.g426c96fcdb
 ------------
-+
+
+or
+
+------------
+$ git config --global trace2.perfTarget ~/log.perf
+$ git version
+git version 2.20.1.155.g426c96fcdb
+------------
+
+yields
+
 ------------
 $ cat ~/log.perf
 12:28:42.620675 common-main.c:38                  | d0 | main                     | version      |     |           |           |            | 2.20.1.155.g426c96fcdb
@@ -66,56 +101,46 @@ $ cat ~/log.perf
 12:28:42.621259 trace2/tr2_tgt_perf.c:211         | d0 | main                     | atexit       |     |  0.001265 |           |            | code:0
 ------------
 
-`GIT_TR2_EVENT` (EVENT)::
+=== The Event Format Target
+
+The event format target is a JSON-based format of event data suitable
+for telemetry analysis.  This format is enabled with the `GIT_TR2_EVENT`
+environment variable or the `trace2.eventTarget` system or global config
+setting.
+
+For example
 
-	a JSON-based format of event data suitable for telemetry analysis.
-+
 ------------
 $ export GIT_TR2_EVENT=~/log.event
 $ git version
 git version 2.20.1.155.g426c96fcdb
 ------------
-+
-------------
-$ cat ~/log.event
-{"event":"version","sid":"sid":"20190408T191610.507018Z-H9b68c35f-P028492","thread":"main","time":"2019-01-16T17:28:42.620713Z","file":"common-main.c","line":38,"evt":"1","exe":"2.20.1.155.g426c96fcdb"}
-{"event":"start","sid":"20190408T191610.507018Z-H9b68c35f-P028492","thread":"main","time":"2019-01-16T17:28:42.621027Z","file":"common-main.c","line":39,"t_abs":0.001173,"argv":["git","version"]}
-{"event":"cmd_name","sid":"20190408T191610.507018Z-H9b68c35f-P028492","thread":"main","time":"2019-01-16T17:28:42.621122Z","file":"git.c","line":432,"name":"version","hierarchy":"version"}
-{"event":"exit","sid":"20190408T191610.507018Z-H9b68c35f-P028492","thread":"main","time":"2019-01-16T17:28:42.621236Z","file":"git.c","line":662,"t_abs":0.001227,"code":0}
-{"event":"atexit","sid":"20190408T191610.507018Z-H9b68c35f-P028492","thread":"main","time":"2019-01-16T17:28:42.621268Z","file":"trace2/tr2_tgt_event.c","line":163,"t_abs":0.001265,"code":0}
-------------
-
-== Enabling a Target
-
-A Trace2 Target is enabled when the corresponding environment variable
-(`GIT_TR2`, `GIT_TR2_PERF`, or `GIT_TR2_EVENT`) is set.  The following
-values are recognized.
-
-`0`::
-`false`::
-
-	Disables the target.
 
-`1`::
-`true`::
+or
 
-	Enables the target and writes stream to `STDERR`.
-
-`[2-9]`::
+------------
+$ git config --global trace2.eventTarget ~/log.event
+$ git version
+git version 2.20.1.155.g426c96fcdb
+------------
 
-	Enables the target and writes to the already opened file descriptor.
+yields
 
-`<absolute-pathname>`::
+------------
+$ cat ~/log.event
+{"event":"version","sid":"sid":"20190408T191610.507018Z-H9b68c35f-P000059a8","thread":"main","time":"2019-01-16T17:28:42.620713Z","file":"common-main.c","line":38,"evt":"1","exe":"2.20.1.155.g426c96fcdb"}
+{"event":"start","sid":"20190408T191610.507018Z-H9b68c35f-P000059a8","thread":"main","time":"2019-01-16T17:28:42.621027Z","file":"common-main.c","line":39,"t_abs":0.001173,"argv":["git","version"]}
+{"event":"cmd_name","sid":"20190408T191610.507018Z-H9b68c35f-P000059a8","thread":"main","time":"2019-01-16T17:28:42.621122Z","file":"git.c","line":432,"name":"version","hierarchy":"version"}
+{"event":"exit","sid":"20190408T191610.507018Z-H9b68c35f-P000059a8","thread":"main","time":"2019-01-16T17:28:42.621236Z","file":"git.c","line":662,"t_abs":0.001227,"code":0}
+{"event":"atexit","sid":"20190408T191610.507018Z-H9b68c35f-P000059a8","thread":"main","time":"2019-01-16T17:28:42.621268Z","file":"trace2/tr2_tgt_event.c","line":163,"t_abs":0.001265,"code":0}
+------------
 
-	Enables the target, opens and writes to the file in append mode.
+=== Enabling a Target
 
-`af_unix:[<socket_type>:]<absolute-pathname>`::
+To enable a target, set the corresponding environment variable or
+system or global config value to one of the following:
 
-	Enables the target, opens and writes to a Unix Domain Socket
-	(on platforms that support them).
-+
-Socket type can be either `stream` or `dgram`.  If the socket type is
-omitted, Git will try both.
+include::../trace2-target-values.txt[]
 
 == Trace2 API
 
@@ -243,15 +268,16 @@ significantly affects program performance or behavior, such as
 	Emits a "def_param" messages for "important" configuration
 	settings.
 +
-The environment variable `GIT_TR2_CONFIG_PARAMS` can be set to a
+The environment variable `GIT_TR2_CONFIG_PARAMS` or the `trace2.configParams`
+config value can be set to a
 list of patterns of important configuration settings, for example:
 `core.*,remote.*.url`.  This function will iterate over all config
 settings and emit a "def_param" message for each match.
 
 `void trace2_cmd_set_config(const char *key, const char *value)`::
 
-	Emits a "def_param" message for a specific configuration
-	setting IFF it matches the `GIT_TR2_CONFIG_PARAMS` pattern.
+	Emits a "def_param" message for a new or updated key/value
+	pair IF `key` is considered important.
 +
 This is used to hook into `git_config_set()` and catch any
 configuration changes and update a value previously reported by
@@ -418,9 +444,6 @@ recursive tree walk.
 
 === NORMAL Format
 
-NORMAL format is enabled when the `GIT_TR2` environment variable is
-set.
-
 Events are written as lines of the form:
 
 ------------
@@ -437,8 +460,8 @@ Events are written as lines of the form:
 Note that this may contain embedded LF or CRLF characters that are
 not escaped, so the event may spill across multiple lines.
 
-If `GIT_TR2_BRIEF` is true, the `time`, `filename`, and `line` fields
-are omitted.
+If `GIT_TR2_BRIEF` or `trace2.normalBrief` is true, the `time`, `filename`,
+and `line` fields are omitted.
 
 This target is intended to be more of a summary (like GIT_TRACE) and
 less detailed than the other targets.  It ignores thread, region, and
@@ -446,9 +469,6 @@ data messages, for example.
 
 === PERF Format
 
-PERF format is enabled when the `GIT_TR2_PERF` environment variable
-is set.
-
 Events are written as lines of the form:
 
 ------------
@@ -508,8 +528,8 @@ This field is in anticipation of in-proc submodules in the future.
 15:33:33.532712 wt-status.c:2331                  | d0 | main                     | region_leave | r1  |  0.127568 |  0.001504 | status     | label:print
 ------------
 
-If `GIT_TR2_PERF_BRIEF` is true, the `time`, `file`, and `line`
-fields are omitted.
+If `GIT_TR2_PERF_BRIEF` or `trace2.perfBrief` is true, the `time`, `file`,
+and `line` fields are omitted.
 
 ------------
 d0 | main                     | region_leave | r1  |  0.011717 |  0.009122 | index      | label:preload
@@ -520,9 +540,6 @@ during development and is quite noisy.
 
 === EVENT Format
 
-EVENT format is enabled when the `GIT_TR2_EVENT` environment
-variable is set.
-
 Each event is a JSON-object containing multiple key/value pairs
 written as a single line and followed by a LF.
 
@@ -540,7 +557,7 @@ The following key/value pairs are common to all events:
 ------------
 {
 	"event":"version",
-	"sid":"20190408T191827.272759Z-H9b68c35f-P011764",
+	"sid":"20190408T191827.272759Z-H9b68c35f-P00003510",
 	"thread":"main",
 	"time":"2019-04-08T19:18:27.282761Z",
 	"file":"common-main.c",
@@ -576,9 +593,9 @@ The following key/value pairs are common to all events:
 `"repo":<repo-id>`::
 	when present, is the integer repo-id as described previously.
 
-If `GIT_TR2_EVENT_BRIEF` is true, the `file` and `line` fields are omitted
-from all events and the `time` field is only present on the "start" and
-"atexit" events.
+If `GIT_TR2_EVENT_BRIEF` or `trace2.eventBrief` is true, the `file`
+and `line` fields are omitted from all events and the `time` field is
+only present on the "start" and "atexit" events.
 
 ==== Event-Specific Key/Value Pairs
 
@@ -889,7 +906,7 @@ visited.
 The `category` field may be used in a future enhancement to
 do category-based filtering.
 +
-The `GIT_TR2_EVENT_NESTING` environment variable can be used to
+`GIT_TR2_EVENT_NESTING` or `trace2.eventNesting` can be used to
 filter deeply nested regions and data events.  It defaults to "2".
 
 `"region_leave"`::
diff --git a/Documentation/trace2-target-values.txt b/Documentation/trace2-target-values.txt
new file mode 100644
index 0000000000..27d3c64e66
--- /dev/null
+++ b/Documentation/trace2-target-values.txt
@@ -0,0 +1,10 @@
+--
+* `0` or `false` - Disables the target.
+* `1` or `true` - Writes to `STDERR`.
+* `[2-9]` - Writes to the already opened file descriptor.
+* `<absolute-pathname>` - Writes to the file in append mode.
+* `af_unix:[<socket_type>:]<absolute-pathname>` - Write to a
+Unix DomainSocket (on platforms that support them).  Socket
+type can be either `stream` or `dgram`; if omitted Git will
+try both.
+--
-- 
gitgitgadget


^ permalink raw reply	[flat|nested] 68+ messages in thread

* [PATCH v5 11/11] trace2: fixup access problem on /etc/gitconfig in read_very_early_config
  2019-04-29 20:14       ` [PATCH v5 00/11] trace2: load trace2 settings from system config Jeff Hostetler via GitGitGadget
                           ` (9 preceding siblings ...)
  2019-04-29 20:14         ` [PATCH v5 10/11] trace2: update docs to describe system/global config settings Jeff Hostetler via GitGitGadget
@ 2019-04-29 20:14         ` Jeff Hostetler via GitGitGadget
  2019-04-29 20:21         ` [PATCH v5 00/11] trace2: load trace2 settings from system config Jeff Hostetler
  11 siblings, 0 replies; 68+ messages in thread
From: Jeff Hostetler via GitGitGadget @ 2019-04-29 20:14 UTC (permalink / raw)
  To: git
  Cc: gitster, peff, jrnieder, steadmon, avarab, Junio C Hamano,
	Jeff Hostetler

From: Jeff Hostetler <jeffhost@microsoft.com>

Teach do_git_config_sequence() to optionally gently check for access to
the system config.  Use this option in read_very_early_config() when
initializing trace2.

In [1] SZEDER Gábor reported that my changes in [2] introduced a
regression when the user does not have permission to read the system
config.

This commit addresses that problem by optionally ignoring that error.

[1] https://public-inbox.org/git/285beb2b2d740ce20fdd8af1becf371ab39703db.1554995916.git.gitgitgadget@gmail.com/T/#m342e839289aec515523a98b5e34d7f42d3f1fd79
[2] https://public-inbox.org/git/285beb2b2d740ce20fdd8af1becf371ab39703db.1554995916.git.gitgitgadget@gmail.com/T/#m11b59c9228c698442f750ee8f9b10c629399ae48

Signed-off-by: Jeff Hostetler <jeffhost@microsoft.com>
---
 config.c | 5 ++++-
 config.h | 1 +
 2 files changed, 5 insertions(+), 1 deletion(-)

diff --git a/config.c b/config.c
index d7a08713a8..3f5ad9dc3c 100644
--- a/config.c
+++ b/config.c
@@ -1676,7 +1676,9 @@ static int do_git_config_sequence(const struct config_options *opts,
 		repo_config = NULL;
 
 	current_parsing_scope = CONFIG_SCOPE_SYSTEM;
-	if (git_config_system() && !access_or_die(git_etc_gitconfig(), R_OK, 0))
+	if (git_config_system() && !access_or_die(git_etc_gitconfig(), R_OK,
+						  opts->system_gently ?
+						  ACCESS_EACCES_OK : 0))
 		ret += git_config_from_file(fn, git_etc_gitconfig(),
 					    data);
 
@@ -1807,6 +1809,7 @@ void read_very_early_config(config_fn_t cb, void *data)
 	opts.ignore_repo = 1;
 	opts.ignore_worktree = 1;
 	opts.ignore_cmdline = 1;
+	opts.system_gently = 1;
 
 	config_with_options(cb, data, NULL, &opts);
 }
diff --git a/config.h b/config.h
index 6a58d61d22..36bb23a9d9 100644
--- a/config.h
+++ b/config.h
@@ -58,6 +58,7 @@ struct config_options {
 	unsigned int ignore_repo : 1;
 	unsigned int ignore_worktree : 1;
 	unsigned int ignore_cmdline : 1;
+	unsigned int system_gently : 1;
 	const char *commondir;
 	const char *git_dir;
 	config_parser_event_fn_t event_fn;
-- 
gitgitgadget

^ permalink raw reply	[flat|nested] 68+ messages in thread

* Re: [PATCH v5 00/11] trace2: load trace2 settings from system config
  2019-04-29 20:14       ` [PATCH v5 00/11] trace2: load trace2 settings from system config Jeff Hostetler via GitGitGadget
                           ` (10 preceding siblings ...)
  2019-04-29 20:14         ` [PATCH v5 11/11] trace2: fixup access problem on /etc/gitconfig in read_very_early_config Jeff Hostetler via GitGitGadget
@ 2019-04-29 20:21         ` Jeff Hostetler
  2019-05-07  1:18           ` Junio C Hamano
  11 siblings, 1 reply; 68+ messages in thread
From: Jeff Hostetler @ 2019-04-29 20:21 UTC (permalink / raw)
  To: Jeff Hostetler via GitGitGadget, git
  Cc: gitster, peff, jrnieder, steadmon, avarab


I forgot to update the cover letter for V5.
V5 adds a commit to fix the permission problem in /etc/gitconfig
reported by SZEDER.

This commit could/should be squashed into commit 5 if wanted.
I left it on top for review purposes.

Jeff


On 4/29/2019 4:14 PM, Jeff Hostetler via GitGitGadget wrote:
> Version 4 fixes a few clang-format warnings and simplifies the PID field in
> the SID.
> 
> Jeff Hostetler (11):
>    config: initialize opts structure in repo_read_config()
>    trace2: refactor setting process starting time
>    trace2: add absolute elapsed time to start event
>    trace2: find exec-dir before trace2 initialization
>    config: add read_very_early_config()
>    trace2: use system/global config for default trace2 settings
>    trace2: report peak memory usage of the process
>    trace2: clarify UTC datetime formatting
>    trace2: make SIDs more unique
>    trace2: update docs to describe system/global config settings
>    trace2: fixup access problem on /etc/gitconfig in
>      read_very_early_config
> 
>   Documentation/config.txt                 |   2 +
>   Documentation/config/trace2.txt          |  56 ++++++++
>   Documentation/technical/api-trace2.txt   | 176 +++++++++++++----------
>   Documentation/trace2-target-values.txt   |  10 ++
>   Makefile                                 |   1 +
>   common-main.c                            |   8 +-
>   compat/mingw.c                           |   2 +
>   compat/win32/trace2_win32_process_info.c |  50 ++++++-
>   config.c                                 |  30 +++-
>   config.h                                 |   5 +
>   t/t0210-trace2-normal.sh                 |  49 ++++++-
>   t/t0211-trace2-perf.sh                   |  43 ++++--
>   t/t0212-trace2-event.sh                  |  42 +++++-
>   trace2.c                                 |  21 ++-
>   trace2.h                                 |  43 ++++--
>   trace2/tr2_cfg.c                         |   7 +-
>   trace2/tr2_dst.c                         |  26 ++--
>   trace2/tr2_dst.h                         |   3 +-
>   trace2/tr2_sid.c                         |  53 ++++++-
>   trace2/tr2_sysenv.c                      | 127 ++++++++++++++++
>   trace2/tr2_sysenv.h                      |  36 +++++
>   trace2/tr2_tbuf.c                        |  19 ++-
>   trace2/tr2_tbuf.h                        |   5 +-
>   trace2/tr2_tgt.h                         |   1 +
>   trace2/tr2_tgt_event.c                   |  53 +++----
>   trace2/tr2_tgt_normal.c                  |  19 +--
>   trace2/tr2_tgt_perf.c                    |  23 +--
>   trace2/tr2_tls.c                         |  38 +++--
>   trace2/tr2_tls.h                         |   8 +-
>   29 files changed, 752 insertions(+), 204 deletions(-)
>   create mode 100644 Documentation/config/trace2.txt
>   create mode 100644 Documentation/trace2-target-values.txt
>   create mode 100644 trace2/tr2_sysenv.c
>   create mode 100644 trace2/tr2_sysenv.h
> 
> 
> base-commit: 041f5ea1cf987a4068ef5f39ba0a09be85952064
> Published-As: https://github.com/gitgitgadget/git/releases/tag/pr-169%2Fjeffhostetler%2Fcore-tr2-startup-and-sysenv-v5
> Fetch-It-Via: git fetch https://github.com/gitgitgadget/git pr-169/jeffhostetler/core-tr2-startup-and-sysenv-v5
> Pull-Request: https://github.com/gitgitgadget/git/pull/169
> 
> Range-diff vs v4:
> 
>    1:  f6653f1c59 =  1:  f6653f1c59 config: initialize opts structure in repo_read_config()
>    2:  48e34834b6 =  2:  48e34834b6 trace2: refactor setting process starting time
>    3:  175371fb54 =  3:  175371fb54 trace2: add absolute elapsed time to start event
>    4:  94729b284c =  4:  94729b284c trace2: find exec-dir before trace2 initialization
>    5:  b0fe1385f1 =  5:  b0fe1385f1 config: add read_very_early_config()
>    6:  550cad6189 =  6:  550cad6189 trace2: use system/global config for default trace2 settings
>    7:  56d8ce3fd6 =  7:  56d8ce3fd6 trace2: report peak memory usage of the process
>    8:  196a9d2c85 =  8:  196a9d2c85 trace2: clarify UTC datetime formatting
>    9:  9fdcb50140 =  9:  9fdcb50140 trace2: make SIDs more unique
>   10:  3414016d04 = 10:  3414016d04 trace2: update docs to describe system/global config settings
>    -:  ---------- > 11:  18ce795360 trace2: fixup access problem on /etc/gitconfig in read_very_early_config
> 

^ permalink raw reply	[flat|nested] 68+ messages in thread

* Re: [PATCH v5 00/11] trace2: load trace2 settings from system config
  2019-04-29 20:21         ` [PATCH v5 00/11] trace2: load trace2 settings from system config Jeff Hostetler
@ 2019-05-07  1:18           ` Junio C Hamano
  0 siblings, 0 replies; 68+ messages in thread
From: Junio C Hamano @ 2019-05-07  1:18 UTC (permalink / raw)
  To: Jeff Hostetler
  Cc: Jeff Hostetler via GitGitGadget, git, peff, jrnieder, steadmon, avarab

Jeff Hostetler <git@jeffhostetler.com> writes:

> I forgot to update the cover letter for V5.
> V5 adds a commit to fix the permission problem in /etc/gitconfig
> reported by SZEDER.
>
> This commit could/should be squashed into commit 5 if wanted.
> I left it on top for review purposes.

I think v4 has been in 'next' for several days already, so an
incremental update like PATCH 11/11 is good.  The first 10 patches
are identical to the previous round, so all is good ;-)

^ permalink raw reply	[flat|nested] 68+ messages in thread

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Thread overview: 68+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2019-03-28 13:30 [PATCH 0/4] trace2: load trace2 settings from system config Jeff Hostetler via GitGitGadget
2019-03-28 13:30 ` [PATCH 1/4] trace2: refactor setting process starting time Jeff Hostetler via GitGitGadget
2019-03-28 13:31 ` [PATCH 2/4] trace2: add absolute elapsed time to start event Jeff Hostetler via GitGitGadget
2019-03-28 13:31 ` [PATCH 3/4] trace2: find exec-dir before trace2 initialization Jeff Hostetler via GitGitGadget
2019-03-28 13:31 ` [PATCH 4/4] trace2: use system config for default trace2 settings Jeff Hostetler via GitGitGadget
2019-03-28 14:36   ` Ævar Arnfjörð Bjarmason
2019-03-28 18:50     ` Jeff Hostetler
2019-03-28 21:28   ` Josh Steadmon
2019-03-29 17:04 ` [PATCH v2 0/7] trace2: load trace2 settings from system config Jeff Hostetler via GitGitGadget
2019-03-29 17:04   ` [PATCH v2 1/7] trace2: refactor setting process starting time Jeff Hostetler via GitGitGadget
2019-03-29 17:04   ` [PATCH v2 2/7] trace2: add absolute elapsed time to start event Jeff Hostetler via GitGitGadget
2019-03-29 17:04   ` [PATCH v2 3/7] trace2: find exec-dir before trace2 initialization Jeff Hostetler via GitGitGadget
2019-03-29 17:04   ` [PATCH v2 4/7] trace2: use system config for default trace2 settings Jeff Hostetler via GitGitGadget
2019-04-01 21:00     ` Josh Steadmon
2019-04-01 21:06       ` Jeff Hostetler
2019-04-03  0:01       ` Jonathan Nieder
2019-04-03  0:00     ` Jonathan Nieder
2019-04-09 15:58       ` Jeff Hostetler
2019-03-29 17:04   ` [PATCH v2 5/7] trace2: report peak memory usage of the process Jeff Hostetler via GitGitGadget
2019-03-29 22:16     ` Ævar Arnfjörð Bjarmason
2019-04-01 21:05       ` Jeff Hostetler
2019-03-29 17:04   ` [PATCH v2 6/7] trace2: clarify UTC datetime formatting Jeff Hostetler via GitGitGadget
2019-03-29 17:04   ` [PATCH v2 7/7] trace2: make SIDs more unique Jeff Hostetler via GitGitGadget
2019-03-29 22:12     ` Ævar Arnfjörð Bjarmason
2019-04-01 21:16       ` Jeff Hostetler
2019-04-01 21:02   ` [PATCH v2 0/7] trace2: load trace2 settings from system config Josh Steadmon
2019-04-11 15:18   ` [PATCH v3 00/10] " Jeff Hostetler via GitGitGadget
2019-04-11 15:18     ` [PATCH v3 01/10] config: initialize opts structure in repo_read_config() Jeff Hostetler via GitGitGadget
2019-04-12  3:52       ` Jonathan Nieder
2019-04-15 14:34         ` Johannes Schindelin
2019-04-11 15:18     ` [PATCH v3 03/10] trace2: add absolute elapsed time to start event Jeff Hostetler via GitGitGadget
2019-04-11 15:18     ` [PATCH v3 02/10] trace2: refactor setting process starting time Jeff Hostetler via GitGitGadget
2019-04-11 15:18     ` [PATCH v3 04/10] trace2: find exec-dir before trace2 initialization Jeff Hostetler via GitGitGadget
2019-04-11 15:18     ` [PATCH v3 05/10] config: add read_very_early_config() Jeff Hostetler via GitGitGadget
2019-04-11 15:18     ` [PATCH v3 06/10] trace2: use system/global config for default trace2 settings Jeff Hostetler via GitGitGadget
2019-04-11 15:18     ` [PATCH v3 07/10] trace2: report peak memory usage of the process Jeff Hostetler via GitGitGadget
2019-04-11 15:18     ` [PATCH v3 08/10] trace2: clarify UTC datetime formatting Jeff Hostetler via GitGitGadget
2019-04-11 15:18     ` [PATCH v3 10/10] trace2: update docs to describe system/global config settings Jeff Hostetler via GitGitGadget
2019-04-11 15:18     ` [PATCH v3 09/10] trace2: make SIDs more unique Jeff Hostetler via GitGitGadget
2019-04-12  2:29     ` [PATCH v3 00/10] trace2: load trace2 settings from system config Junio C Hamano
2019-04-12 13:47       ` Jeff Hostetler
2019-04-15 20:39     ` [PATCH v4 " Jeff Hostetler via GitGitGadget
2019-04-15 20:39       ` [PATCH v4 01/10] config: initialize opts structure in repo_read_config() Jeff Hostetler via GitGitGadget
2019-04-15 20:39       ` [PATCH v4 02/10] trace2: refactor setting process starting time Jeff Hostetler via GitGitGadget
2019-04-15 20:39       ` [PATCH v4 03/10] trace2: add absolute elapsed time to start event Jeff Hostetler via GitGitGadget
2019-04-15 20:39       ` [PATCH v4 04/10] trace2: find exec-dir before trace2 initialization Jeff Hostetler via GitGitGadget
2019-04-15 20:39       ` [PATCH v4 05/10] config: add read_very_early_config() Jeff Hostetler via GitGitGadget
2019-04-15 20:39       ` [PATCH v4 06/10] trace2: use system/global config for default trace2 settings Jeff Hostetler via GitGitGadget
2019-04-27 13:43         ` SZEDER Gábor
2019-04-29 19:03           ` Jeff Hostetler
2019-04-15 20:39       ` [PATCH v4 08/10] trace2: clarify UTC datetime formatting Jeff Hostetler via GitGitGadget
2019-04-15 20:39       ` [PATCH v4 07/10] trace2: report peak memory usage of the process Jeff Hostetler via GitGitGadget
2019-04-15 20:39       ` [PATCH v4 09/10] trace2: make SIDs more unique Jeff Hostetler via GitGitGadget
2019-04-15 20:39       ` [PATCH v4 10/10] trace2: update docs to describe system/global config settings Jeff Hostetler via GitGitGadget
2019-04-29 20:14       ` [PATCH v5 00/11] trace2: load trace2 settings from system config Jeff Hostetler via GitGitGadget
2019-04-29 20:14         ` [PATCH v5 01/11] config: initialize opts structure in repo_read_config() Jeff Hostetler via GitGitGadget
2019-04-29 20:14         ` [PATCH v5 02/11] trace2: refactor setting process starting time Jeff Hostetler via GitGitGadget
2019-04-29 20:14         ` [PATCH v5 03/11] trace2: add absolute elapsed time to start event Jeff Hostetler via GitGitGadget
2019-04-29 20:14         ` [PATCH v5 04/11] trace2: find exec-dir before trace2 initialization Jeff Hostetler via GitGitGadget
2019-04-29 20:14         ` [PATCH v5 05/11] config: add read_very_early_config() Jeff Hostetler via GitGitGadget
2019-04-29 20:14         ` [PATCH v5 06/11] trace2: use system/global config for default trace2 settings Jeff Hostetler via GitGitGadget
2019-04-29 20:14         ` [PATCH v5 07/11] trace2: report peak memory usage of the process Jeff Hostetler via GitGitGadget
2019-04-29 20:14         ` [PATCH v5 09/11] trace2: make SIDs more unique Jeff Hostetler via GitGitGadget
2019-04-29 20:14         ` [PATCH v5 08/11] trace2: clarify UTC datetime formatting Jeff Hostetler via GitGitGadget
2019-04-29 20:14         ` [PATCH v5 10/11] trace2: update docs to describe system/global config settings Jeff Hostetler via GitGitGadget
2019-04-29 20:14         ` [PATCH v5 11/11] trace2: fixup access problem on /etc/gitconfig in read_very_early_config Jeff Hostetler via GitGitGadget
2019-04-29 20:21         ` [PATCH v5 00/11] trace2: load trace2 settings from system config Jeff Hostetler
2019-05-07  1:18           ` Junio C Hamano

git@vger.kernel.org list mirror (unofficial, one of many)

Archives are clonable:
	git clone --mirror https://public-inbox.org/git
	git clone --mirror http://ou63pmih66umazou.onion/git
	git clone --mirror http://czquwvybam4bgbro.onion/git
	git clone --mirror http://hjrcffqmbrq6wope.onion/git

Example config snippet for mirrors

Newsgroups are available over NNTP:
	nntp://news.public-inbox.org/inbox.comp.version-control.git
	nntp://ou63pmih66umazou.onion/inbox.comp.version-control.git
	nntp://czquwvybam4bgbro.onion/inbox.comp.version-control.git
	nntp://hjrcffqmbrq6wope.onion/inbox.comp.version-control.git
	nntp://news.gmane.org/gmane.comp.version-control.git

 note: .onion URLs require Tor: https://www.torproject.org/

AGPL code for this site: git clone https://public-inbox.org/ public-inbox