[PATCH 00/11] FSMonitor Preliminary Commits

[PATCH 00/11] FSMonitor Preliminary Commits

[Jeff Hostetler via GitGitGadget]

This patch series fixes runtime errors in t/perf/p7519 on Windows and MacOS.
It adds Trace2 logging to p7519 to make it easier to compare results when
Watchman is enabled and disabled. And finally, it adds some Trace2 regions
and data events around our usage of Watchman and the existing FSMonitor
framework.

This series is independent of the "Simple IPC" series.

A future series to add a builtin FSMonitor daemon will build upon both of
these series.

Jeff Hostetler (10):
  p7519: use xargs -0 rather than -d in test
  p7519: fix watchman watch-list test on Windows
  p7519: move watchman cleanup earlier in the test
  p7519: add trace logging during perf test
  preload-index: log the number of lstat calls to trace2
  read-cache: log the number of lstat calls to trace2
  read-cache: log the number of scanned files to trace2
  fsmonitor: log invocation of FSMonitor hook to trace2
  fsmonitor: log FSMN token when reading and writing the index
  fsmonitor: refactor initialization of fsmonitor_last_update token

Kevin Willford (1):
  fsmonitor: allow all entries for a folder to be invalidated

 fsmonitor.c               | 107 ++++++++++++++++++++++++++++++++++----
 fsmonitor.h               |   5 ++
 preload-index.c           |  10 ++++
 read-cache.c              |  24 +++++++--
 t/perf/.gitignore         |   1 +
 t/perf/Makefile           |   4 +-
 t/perf/p7519-fsmonitor.sh |  61 ++++++++++++++++++----
 7 files changed, 186 insertions(+), 26 deletions(-)


base-commit: 71ca53e8125e36efbda17293c50027d31681a41f
Published-As: https://github.com/gitgitgadget/git/releases/tag/pr-860%2Fjeffhostetler%2Ffsmonitor-prework-v1
Fetch-It-Via: git fetch https://github.com/gitgitgadget/git pr-860/jeffhostetler/fsmonitor-prework-v1
Pull-Request: https://github.com/gitgitgadget/git/pull/860
-- 
gitgitgadget

[PATCH 01/11] p7519: use xargs -0 rather than -d in test

[Jeff Hostetler via GitGitGadget]

From: Jeff Hostetler <jeffhost@microsoft.com>

The Mac version of xargs does not support the "-d" option.  Convert the test
setup to pipe the data set thru `lf_to_nul | xargs -0` instead.

Signed-off-by: Jeff Hostetler <jeffhost@microsoft.com>
---
 t/perf/p7519-fsmonitor.sh | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/t/perf/p7519-fsmonitor.sh b/t/perf/p7519-fsmonitor.sh
index 9b43342806b..7bb37e9a6c1 100755
--- a/t/perf/p7519-fsmonitor.sh
+++ b/t/perf/p7519-fsmonitor.sh
@@ -165,7 +165,7 @@ test_fsmonitor_suite() {
 	'
 
 	test_perf_w_drop_caches "status (dirty) ($DESC)" '
-		git ls-files | head -100000 | xargs -d "\n" touch -h &&
+		git ls-files | head -100000 | lf_to_nul | xargs -0 touch -h &&
 		git status
 	'
 
-- 
gitgitgadget

[PATCH 02/11] p7519: fix watchman watch-list test on Windows

[Jeff Hostetler via GitGitGadget]

From: Jeff Hostetler <jeffhost@microsoft.com>

Only use the final portion of the test trash directory file name
when verifying that Watchman was started.

On Windows and under the SDK, $GIT_WORKTREE is a cygwin-style
path with forward slashes and a "/c/" drive name.  However
`watchman watch-list` reports a proper Windows-style pathname
with drive letters and backslashes.  This causes the grep to
fail.  Since we don't really care about the full pathname (and
we really don't want to bother with normalizaing them), just see
if the test-name portion of the path is found.

Signed-off-by: Jeff Hostetler <jeffhost@microsoft.com>
---
 t/perf/p7519-fsmonitor.sh | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/t/perf/p7519-fsmonitor.sh b/t/perf/p7519-fsmonitor.sh
index 7bb37e9a6c1..e5a4b0582fb 100755
--- a/t/perf/p7519-fsmonitor.sh
+++ b/t/perf/p7519-fsmonitor.sh
@@ -101,7 +101,7 @@ test_expect_success "one time repo setup" '
 	# If Watchman exists, watch the work tree and attempt a query.
 	if test_have_prereq WATCHMAN; then
 		watchman watch "$GIT_WORK_TREE" &&
-		watchman watch-list | grep -q -F "$GIT_WORK_TREE"
+		watchman watch-list | grep -q -F "p7519-fsmonitor"
 	fi
 '
 
-- 
gitgitgadget

[PATCH 03/11] p7519: move watchman cleanup earlier in the test

[Jeff Hostetler via GitGitGadget]

From: Jeff Hostetler <jeffhost@microsoft.com>

Shutdown Watchman after the Watchman-based tests and before the block of
"no fsmonitor" tests.

This helps ensure that Watchman cannot affect the test results for the
other.

Signed-off-by: Jeff Hostetler <jeffhost@microsoft.com>
---
 t/perf/p7519-fsmonitor.sh | 25 +++++++++++++++++--------
 1 file changed, 17 insertions(+), 8 deletions(-)

diff --git a/t/perf/p7519-fsmonitor.sh b/t/perf/p7519-fsmonitor.sh
index e5a4b0582fb..45bbba3c92f 100755
--- a/t/perf/p7519-fsmonitor.sh
+++ b/t/perf/p7519-fsmonitor.sh
@@ -198,6 +198,11 @@ test_fsmonitor_suite() {
 	'
 }
 
+#
+# Run a full set of perf tests using each Hook-based fsmonitor provider,
+# such as Watchman.
+#
+
 if test -n "$GIT_PERF_7519_FSMONITOR"; then
 	for INTEGRATION_PATH in $GIT_PERF_7519_FSMONITOR; do
 		test_expect_success "setup for fsmonitor $INTEGRATION_PATH" 'setup_for_fsmonitor'
@@ -208,14 +213,6 @@ else
 	test_fsmonitor_suite
 fi
 
-test_expect_success "setup without fsmonitor" '
-	unset INTEGRATION_SCRIPT &&
-	git config --unset core.fsmonitor &&
-	git update-index --no-fsmonitor
-'
-
-test_fsmonitor_suite
-
 if test_have_prereq WATCHMAN
 then
 	watchman watch-del "$GIT_WORK_TREE" >/dev/null 2>&1 &&
@@ -225,4 +222,16 @@ then
 	watchman shutdown-server >/dev/null 2>&1
 fi
 
+#
+# Run a full set of perf tests with the fsmonitor feature disabled.
+#
+
+test_expect_success "setup without fsmonitor" '
+	unset INTEGRATION_SCRIPT &&
+	git config --unset core.fsmonitor &&
+	git update-index --no-fsmonitor
+'
+
+test_fsmonitor_suite
+
 test_done
-- 
gitgitgadget

[PATCH 04/11] p7519: add trace logging during perf test

[Jeff Hostetler via GitGitGadget]

From: Jeff Hostetler <jeffhost@microsoft.com>

Add optional trace logging to allow us to better compare performance of
various fsmonitor providers and compare results with non-fsmonitor runs.

Currently, this includes Trace2 logging, but may be extended to include
other trace targets, such as GIT_TRACE_FSMONITOR if desired.

Using this logging helped me explain an odd behavior on MacOS where the
kernel was dropping events and causing the hook to Watchman to timeout.

Signed-off-by: Jeff Hostetler <jeffhost@microsoft.com>
---
 t/perf/.gitignore         |  1 +
 t/perf/Makefile           |  4 ++--
 t/perf/p7519-fsmonitor.sh | 32 ++++++++++++++++++++++++++++++++
 3 files changed, 35 insertions(+), 2 deletions(-)

diff --git a/t/perf/.gitignore b/t/perf/.gitignore
index 982eb8e3a94..72f5d0d3148 100644
--- a/t/perf/.gitignore
+++ b/t/perf/.gitignore
@@ -1,3 +1,4 @@
 /build/
 /test-results/
+/test-trace/
 /trash directory*/
diff --git a/t/perf/Makefile b/t/perf/Makefile
index fcb0e8865e4..2465770a782 100644
--- a/t/perf/Makefile
+++ b/t/perf/Makefile
@@ -7,10 +7,10 @@ perf: pre-clean
 	./run
 
 pre-clean:
-	rm -rf test-results
+	rm -rf test-results test-trace
 
 clean:
-	rm -rf build "trash directory".* test-results
+	rm -rf build "trash directory".* test-results test-trace
 
 test-lint:
 	$(MAKE) -C .. test-lint
diff --git a/t/perf/p7519-fsmonitor.sh b/t/perf/p7519-fsmonitor.sh
index 45bbba3c92f..e6724d3604b 100755
--- a/t/perf/p7519-fsmonitor.sh
+++ b/t/perf/p7519-fsmonitor.sh
@@ -32,6 +32,8 @@ test_description="Test core.fsmonitor"
 #
 # GIT_PERF_7519_DROP_CACHE: if set, the OS caches are dropped between tests
 #
+# GIT_PERF_7519_TRACE: if set, enable trace logging during the test.
+#   Trace logs will be grouped by fsmonitor provider.
 
 test_perf_large_repo
 test_checkout_worktree
@@ -70,6 +72,32 @@ then
 	fi
 fi
 
+trace_start() {
+	if test -n "$GIT_PERF_7519_TRACE"
+	then
+		name="$1"
+		TEST_TRACE_DIR="$TEST_OUTPUT_DIRECTORY/test-trace/p7519/"
+		echo "Writing trace logging to $TEST_TRACE_DIR"
+
+		mkdir -p "$TEST_TRACE_DIR"
+
+		# Start Trace2 logging and any other GIT_TRACE_* logs that you
+		# want for this named test case.
+
+		GIT_TRACE2_PERF="$TEST_TRACE_DIR/$name.trace2perf"
+		export GIT_TRACE2_PERF
+
+		>"$GIT_TRACE2_PERF"
+	fi
+}
+
+trace_stop() {
+	if test -n "$GIT_PERF_7519_TRACE"
+	then
+		unset GIT_TRACE2_PERF
+	fi
+}
+
 test_expect_success "one time repo setup" '
 	# set untrackedCache depending on the environment
 	if test -n "$GIT_PERF_7519_UNTRACKED_CACHE"
@@ -203,6 +231,7 @@ test_fsmonitor_suite() {
 # such as Watchman.
 #
 
+trace_start fsmonitor-watchman
 if test -n "$GIT_PERF_7519_FSMONITOR"; then
 	for INTEGRATION_PATH in $GIT_PERF_7519_FSMONITOR; do
 		test_expect_success "setup for fsmonitor $INTEGRATION_PATH" 'setup_for_fsmonitor'
@@ -221,11 +250,13 @@ then
 	# preventing the removal of the trash directory
 	watchman shutdown-server >/dev/null 2>&1
 fi
+trace_stop
 
 #
 # Run a full set of perf tests with the fsmonitor feature disabled.
 #
 
+trace_start fsmonitor-disabled
 test_expect_success "setup without fsmonitor" '
 	unset INTEGRATION_SCRIPT &&
 	git config --unset core.fsmonitor &&
@@ -233,5 +264,6 @@ test_expect_success "setup without fsmonitor" '
 '
 
 test_fsmonitor_suite
+trace_stop
 
 test_done
-- 
gitgitgadget

[PATCH 05/11] preload-index: log the number of lstat calls to trace2

[Jeff Hostetler via GitGitGadget]

From: Jeff Hostetler <jeffhost@microsoft.com>

Report the total number of calls made to lstat() inside preload_index().

FSMonitor improves the performance of commands like `git status` by
avoiding scanning the disk for changed files.  This can be seen in
`preload_index()`.  Let's measure this.

Signed-off-by: Jeff Hostetler <jeffhost@microsoft.com>
---
 preload-index.c | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/preload-index.c b/preload-index.c
index ed6eaa47388..e5529a58636 100644
--- a/preload-index.c
+++ b/preload-index.c
@@ -31,6 +31,7 @@ struct thread_data {
 	struct pathspec pathspec;
 	struct progress_data *progress;
 	int offset, nr;
+	int t2_nr_lstat;
 };
 
 static void *preload_thread(void *_data)
@@ -73,6 +74,7 @@ static void *preload_thread(void *_data)
 			continue;
 		if (threaded_has_symlink_leading_path(&cache, ce->name, ce_namelen(ce)))
 			continue;
+		p->t2_nr_lstat++;
 		if (lstat(ce->name, &st))
 			continue;
 		if (ie_match_stat(index, ce, &st, CE_MATCH_RACY_IS_DIRTY|CE_MATCH_IGNORE_FSMONITOR))
@@ -98,6 +100,7 @@ void preload_index(struct index_state *index,
 	int threads, i, work, offset;
 	struct thread_data data[MAX_PARALLEL];
 	struct progress_data pd;
+	int t2_sum_lstat = 0;
 
 	if (!HAVE_THREADS || !core_preload_index)
 		return;
@@ -107,6 +110,9 @@ void preload_index(struct index_state *index,
 		threads = 2;
 	if (threads < 2)
 		return;
+
+	trace2_region_enter("index", "preload", NULL);
+
 	trace_performance_enter();
 	if (threads > MAX_PARALLEL)
 		threads = MAX_PARALLEL;
@@ -141,10 +147,14 @@ void preload_index(struct index_state *index,
 		struct thread_data *p = data+i;
 		if (pthread_join(p->pthread, NULL))
 			die("unable to join threaded lstat");
+		t2_sum_lstat += p->t2_nr_lstat;
 	}
 	stop_progress(&pd.progress);
 
 	trace_performance_leave("preload index");
+
+	trace2_data_intmax("index", NULL, "preload/sum_lstat", t2_sum_lstat);
+	trace2_region_leave("index", "preload", NULL);
 }
 
 int repo_read_index_preload(struct repository *repo,
-- 
gitgitgadget

[PATCH 06/11] read-cache: log the number of lstat calls to trace2

[Jeff Hostetler via GitGitGadget]

From: Jeff Hostetler <jeffhost@microsoft.com>

Report the total number of calls made to lstat() inside of refresh_index().

FSMonitor improves the performance of commands like `git status` by
avoiding scanning the disk for changed files.  This can be seen in
`refresh_index()`.  Let's measure this.

Signed-off-by: Jeff Hostetler <jeffhost@microsoft.com>
---
 read-cache.c | 17 ++++++++++++++---
 1 file changed, 14 insertions(+), 3 deletions(-)

diff --git a/read-cache.c b/read-cache.c
index ecf6f689940..893cc41e1d9 100644
--- a/read-cache.c
+++ b/read-cache.c
@@ -1364,7 +1364,8 @@ int add_index_entry(struct index_state *istate, struct cache_entry *ce, int opti
 static struct cache_entry *refresh_cache_ent(struct index_state *istate,
 					     struct cache_entry *ce,
 					     unsigned int options, int *err,
-					     int *changed_ret)
+					     int *changed_ret,
+					     int *t2_did_lstat)
 {
 	struct stat st;
 	struct cache_entry *updated;
@@ -1406,6 +1407,8 @@ static struct cache_entry *refresh_cache_ent(struct index_state *istate,
 		return NULL;
 	}
 
+	if (t2_did_lstat)
+		*t2_did_lstat = 1;
 	if (lstat(ce->name, &st) < 0) {
 		if (ignore_missing && errno == ENOENT)
 			return ce;
@@ -1519,6 +1522,7 @@ int refresh_index(struct index_state *istate, unsigned int flags,
 	const char *added_fmt;
 	const char *unmerged_fmt;
 	struct progress *progress = NULL;
+	int t2_sum_lstat = 0;
 
 	if (flags & REFRESH_PROGRESS && isatty(2))
 		progress = start_delayed_progress(_("Refresh index"),
@@ -1536,11 +1540,13 @@ int refresh_index(struct index_state *istate, unsigned int flags,
 	 * we only have to do the special cases that are left.
 	 */
 	preload_index(istate, pathspec, 0);
+	trace2_region_enter("index", "refresh", NULL);
 	for (i = 0; i < istate->cache_nr; i++) {
 		struct cache_entry *ce, *new_entry;
 		int cache_errno = 0;
 		int changed = 0;
 		int filtered = 0;
+		int t2_did_lstat = 0;
 
 		ce = istate->cache[i];
 		if (ignore_submodules && S_ISGITLINK(ce->ce_mode))
@@ -1566,7 +1572,10 @@ int refresh_index(struct index_state *istate, unsigned int flags,
 		if (filtered)
 			continue;
 
-		new_entry = refresh_cache_ent(istate, ce, options, &cache_errno, &changed);
+		new_entry = refresh_cache_ent(istate, ce, options,
+					      &cache_errno, &changed,
+					      &t2_did_lstat);
+		t2_sum_lstat += t2_did_lstat;
 		if (new_entry == ce)
 			continue;
 		if (progress)
@@ -1602,6 +1611,8 @@ int refresh_index(struct index_state *istate, unsigned int flags,
 
 		replace_index_entry(istate, i, new_entry);
 	}
+	trace2_data_intmax("index", NULL, "refresh/sum_lstat", t2_sum_lstat);
+	trace2_region_leave("index", "refresh", NULL);
 	if (progress) {
 		display_progress(progress, istate->cache_nr);
 		stop_progress(&progress);
@@ -1614,7 +1625,7 @@ struct cache_entry *refresh_cache_entry(struct index_state *istate,
 					struct cache_entry *ce,
 					unsigned int options)
 {
-	return refresh_cache_ent(istate, ce, options, NULL, NULL);
+	return refresh_cache_ent(istate, ce, options, NULL, NULL, NULL);
 }
 
 
-- 
gitgitgadget

[PATCH 07/11] read-cache: log the number of scanned files to trace2

[Jeff Hostetler via GitGitGadget]

From: Jeff Hostetler <jeffhost@microsoft.com>

Report the number of files in the working directory that were read and
their hashes verified in `refresh_index()`.

FSMonitor improves the performance of commands like `git status` by
avoiding scanning the disk for changed files.  Let's measure this.

Signed-off-by: Jeff Hostetler <jeffhost@microsoft.com>
---
 read-cache.c | 13 ++++++++++---
 1 file changed, 10 insertions(+), 3 deletions(-)

diff --git a/read-cache.c b/read-cache.c
index 893cc41e1d9..c9dd7f4015e 100644
--- a/read-cache.c
+++ b/read-cache.c
@@ -1365,7 +1365,8 @@ static struct cache_entry *refresh_cache_ent(struct index_state *istate,
 					     struct cache_entry *ce,
 					     unsigned int options, int *err,
 					     int *changed_ret,
-					     int *t2_did_lstat)
+					     int *t2_did_lstat,
+					     int *t2_did_scan)
 {
 	struct stat st;
 	struct cache_entry *updated;
@@ -1445,6 +1446,8 @@ static struct cache_entry *refresh_cache_ent(struct index_state *istate,
 		}
 	}
 
+	if (t2_did_scan)
+		*t2_did_scan = 1;
 	if (ie_modified(istate, ce, &st, options)) {
 		if (err)
 			*err = EINVAL;
@@ -1523,6 +1526,7 @@ int refresh_index(struct index_state *istate, unsigned int flags,
 	const char *unmerged_fmt;
 	struct progress *progress = NULL;
 	int t2_sum_lstat = 0;
+	int t2_sum_scan = 0;
 
 	if (flags & REFRESH_PROGRESS && isatty(2))
 		progress = start_delayed_progress(_("Refresh index"),
@@ -1547,6 +1551,7 @@ int refresh_index(struct index_state *istate, unsigned int flags,
 		int changed = 0;
 		int filtered = 0;
 		int t2_did_lstat = 0;
+		int t2_did_scan = 0;
 
 		ce = istate->cache[i];
 		if (ignore_submodules && S_ISGITLINK(ce->ce_mode))
@@ -1574,8 +1579,9 @@ int refresh_index(struct index_state *istate, unsigned int flags,
 
 		new_entry = refresh_cache_ent(istate, ce, options,
 					      &cache_errno, &changed,
-					      &t2_did_lstat);
+					      &t2_did_lstat, &t2_did_scan);
 		t2_sum_lstat += t2_did_lstat;
+		t2_sum_scan += t2_did_scan;
 		if (new_entry == ce)
 			continue;
 		if (progress)
@@ -1612,6 +1618,7 @@ int refresh_index(struct index_state *istate, unsigned int flags,
 		replace_index_entry(istate, i, new_entry);
 	}
 	trace2_data_intmax("index", NULL, "refresh/sum_lstat", t2_sum_lstat);
+	trace2_data_intmax("index", NULL, "refresh/sum_scan", t2_sum_scan);
 	trace2_region_leave("index", "refresh", NULL);
 	if (progress) {
 		display_progress(progress, istate->cache_nr);
@@ -1625,7 +1632,7 @@ struct cache_entry *refresh_cache_entry(struct index_state *istate,
 					struct cache_entry *ce,
 					unsigned int options)
 {
-	return refresh_cache_ent(istate, ce, options, NULL, NULL, NULL);
+	return refresh_cache_ent(istate, ce, options, NULL, NULL, NULL, NULL);
 }
 
 
-- 
gitgitgadget

[PATCH 08/11] fsmonitor: log invocation of FSMonitor hook to trace2

[Jeff Hostetler via GitGitGadget]

From: Jeff Hostetler <jeffhost@microsoft.com>

Let's measure the time taken to request and receive FSMonitor data
via the hook API and the size of the response.

Signed-off-by: Jeff Hostetler <jeffhost@microsoft.com>
---
 fsmonitor.c | 29 ++++++++++++++++++++++++++++-
 fsmonitor.h |  5 +++++
 2 files changed, 33 insertions(+), 1 deletion(-)

diff --git a/fsmonitor.c b/fsmonitor.c
index ca031c3abb8..7a2be24cd43 100644
--- a/fsmonitor.c
+++ b/fsmonitor.c
@@ -142,6 +142,7 @@ void write_fsmonitor_extension(struct strbuf *sb, struct index_state *istate)
 static int query_fsmonitor(int version, const char *last_update, struct strbuf *query_result)
 {
 	struct child_process cp = CHILD_PROCESS_INIT;
+	int result;
 
 	if (!core_fsmonitor)
 		return -1;
@@ -152,7 +153,33 @@ static int query_fsmonitor(int version, const char *last_update, struct strbuf *
 	cp.use_shell = 1;
 	cp.dir = get_git_work_tree();
 
-	return capture_command(&cp, query_result, 1024);
+	trace2_region_enter("fsm_hook", "query", NULL);
+
+	result = capture_command(&cp, query_result, 1024);
+
+	if (result)
+		trace2_data_intmax("fsm_hook", NULL, "query/failed", result);
+	else {
+		trace2_data_intmax("fsm_hook", NULL, "query/response-length",
+				   query_result->len);
+
+		if (fsmonitor_is_trivial_response(query_result))
+			trace2_data_intmax("fsm_hook", NULL,
+					   "query/trivial-response", 1);
+	}
+
+	trace2_region_leave("fsm_hook", "query", NULL);
+
+	return result;
+}
+
+int fsmonitor_is_trivial_response(const struct strbuf *query_result)
+{
+	static char trivial_response[3] = { '\0', '/', '\0' };
+	int is_trivial = !memcmp(trivial_response,
+				 &query_result->buf[query_result->len - 3], 3);
+
+	return is_trivial;
 }
 
 static void fsmonitor_refresh_callback(struct index_state *istate, const char *name)
diff --git a/fsmonitor.h b/fsmonitor.h
index 739318ab6d1..7f1794b90b0 100644
--- a/fsmonitor.h
+++ b/fsmonitor.h
@@ -44,6 +44,11 @@ void tweak_fsmonitor(struct index_state *istate);
  */
 void refresh_fsmonitor(struct index_state *istate);
 
+/*
+ * Does the received result contain the "trivial" response?
+ */
+int fsmonitor_is_trivial_response(const struct strbuf *query_result);
+
 /*
  * Set the given cache entries CE_FSMONITOR_VALID bit. This should be
  * called any time the cache entry has been updated to reflect the
-- 
gitgitgadget

[PATCH 09/11] fsmonitor: log FSMN token when reading and writing the index

[Jeff Hostetler via GitGitGadget]

From: Jeff Hostetler <jeffhost@microsoft.com>

Signed-off-by: Jeff Hostetler <jeffhost@microsoft.com>
---
 fsmonitor.c | 12 ++++++++++--
 1 file changed, 10 insertions(+), 2 deletions(-)

diff --git a/fsmonitor.c b/fsmonitor.c
index 7a2be24cd43..3105dc370ab 100644
--- a/fsmonitor.c
+++ b/fsmonitor.c
@@ -87,7 +87,11 @@ int read_fsmonitor_extension(struct index_state *istate, const void *data,
 		BUG("fsmonitor_dirty has more entries than the index (%"PRIuMAX" > %u)",
 		    (uintmax_t)istate->fsmonitor_dirty->bit_size, istate->cache_nr);
 
-	trace_printf_key(&trace_fsmonitor, "read fsmonitor extension successful");
+	trace2_data_string("index", NULL, "extension/fsmn/read/token",
+			   istate->fsmonitor_last_update);
+	trace_printf_key(&trace_fsmonitor,
+			 "read fsmonitor extension successful '%s'",
+			 istate->fsmonitor_last_update);
 	return 0;
 }
 
@@ -133,7 +137,11 @@ void write_fsmonitor_extension(struct strbuf *sb, struct index_state *istate)
 	put_be32(&ewah_size, sb->len - ewah_start);
 	memcpy(sb->buf + fixup, &ewah_size, sizeof(uint32_t));
 
-	trace_printf_key(&trace_fsmonitor, "write fsmonitor extension successful");
+	trace2_data_string("index", NULL, "extension/fsmn/write/token",
+			   istate->fsmonitor_last_update);
+	trace_printf_key(&trace_fsmonitor,
+			 "write fsmonitor extension successful '%s'",
+			 istate->fsmonitor_last_update);
 }
 
 /*
-- 
gitgitgadget

[PATCH 10/11] fsmonitor: allow all entries for a folder to be invalidated

[Kevin Willford via GitGitGadget]

From: Kevin Willford <Kevin.Willford@microsoft.com>

Allow fsmonitor to report directory changes by reporting paths with a
trailing slash.

Signed-off-by: Jeff Hostetler <jeffhost@microsoft.com>
Signed-off-by: Kevin Willford <Kevin.Willford@microsoft.com>
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
---
 fsmonitor.c | 31 ++++++++++++++++++++++++++-----
 1 file changed, 26 insertions(+), 5 deletions(-)

diff --git a/fsmonitor.c b/fsmonitor.c
index 3105dc370ab..64deeda597e 100644
--- a/fsmonitor.c
+++ b/fsmonitor.c
@@ -190,13 +190,34 @@ int fsmonitor_is_trivial_response(const struct strbuf *query_result)
 	return is_trivial;
 }
 
-static void fsmonitor_refresh_callback(struct index_state *istate, const char *name)
+static void fsmonitor_refresh_callback(struct index_state *istate, char *name)
 {
-	int pos = index_name_pos(istate, name, strlen(name));
+	int i, len = strlen(name);
+	if (name[len - 1] == '/') {
+
+		/*
+		 * TODO We should binary search to find the first path with
+		 * TODO this directory prefix.  Then linearly update entries
+		 * TODO while the prefix matches.  Taking care to search without
+		 * TODO the trailing slash -- because '/' sorts after a few
+		 * TODO interesting special chars, like '.' and ' '.
+		 */
+
+		/* Mark all entries for the folder invalid */
+		for (i = 0; i < istate->cache_nr; i++) {
+			if (istate->cache[i]->ce_flags & CE_FSMONITOR_VALID &&
+			    starts_with(istate->cache[i]->name, name))
+				istate->cache[i]->ce_flags &= ~CE_FSMONITOR_VALID;
+		}
+		/* Need to remove the / from the path for the untracked cache */
+		name[len - 1] = '\0';
+	} else {
+		int pos = index_name_pos(istate, name, strlen(name));
 
-	if (pos >= 0) {
-		struct cache_entry *ce = istate->cache[pos];
-		ce->ce_flags &= ~CE_FSMONITOR_VALID;
+		if (pos >= 0) {
+			struct cache_entry *ce = istate->cache[pos];
+			ce->ce_flags &= ~CE_FSMONITOR_VALID;
+		}
 	}
 
 	/*
-- 
gitgitgadget

[PATCH 11/11] fsmonitor: refactor initialization of fsmonitor_last_update token

[Jeff Hostetler via GitGitGadget]

From: Jeff Hostetler <jeffhost@microsoft.com>

Isolate and document initialization of `istate->fsmonitor_last_update`.
This field should contain a fsmonitor-specific opaque token, but we
need to initialize it before we can actually talk to a fsmonitor process,
so we create a generic default value.

Signed-off-by: Jeff Hostetler <jeffhost@microsoft.com>
---
 fsmonitor.c | 35 ++++++++++++++++++++++++++++++++---
 1 file changed, 32 insertions(+), 3 deletions(-)

diff --git a/fsmonitor.c b/fsmonitor.c
index 64deeda597e..e12214b3007 100644
--- a/fsmonitor.c
+++ b/fsmonitor.c
@@ -343,16 +343,45 @@ void refresh_fsmonitor(struct index_state *istate)
 	istate->fsmonitor_last_update = strbuf_detach(&last_update_token, NULL);
 }
 
+/*
+ * The caller wants to turn on FSMonitor.  And when the caller writes
+ * the index to disk, a FSMonitor extension should be included.  This
+ * requires that `istate->fsmonitor_last_update` not be NULL.  But we
+ * have not actually talked to a FSMonitor process yet, so we don't
+ * have an initial value for this field.
+ *
+ * For a protocol V1 FSMonitor process, this field is a formatted
+ * "nanoseconds since epoch" field.  However, for a protocol V2
+ * FSMonitor process, this field is an opaque token.
+ *
+ * Historically, `add_fsmonitor()` has initialized this field to the
+ * current time for protocol V1 processes.  There are lots of race
+ * conditions here, but that code has shipped...
+ *
+ * The only true solution is to use a V2 FSMonitor and get a current
+ * or default token value (that it understands), but we cannot do that
+ * until we have actually talked to an instance of the FSMonitor process
+ * (but the protocol requires that we send a token first...).
+ *
+ * For simplicity, just initialize like we have a V1 process and require
+ * that V2 processes adapt.
+ */
+static void initialize_fsmonitor_last_update(struct index_state *istate)
+{
+	struct strbuf last_update = STRBUF_INIT;
+
+	strbuf_addf(&last_update, "%"PRIu64"", getnanotime());
+	istate->fsmonitor_last_update = strbuf_detach(&last_update, NULL);
+}
+
 void add_fsmonitor(struct index_state *istate)
 {
 	unsigned int i;
-	struct strbuf last_update = STRBUF_INIT;
 
 	if (!istate->fsmonitor_last_update) {
 		trace_printf_key(&trace_fsmonitor, "add fsmonitor");
 		istate->cache_changed |= FSMONITOR_CHANGED;
-		strbuf_addf(&last_update, "%"PRIu64"", getnanotime());
-		istate->fsmonitor_last_update = strbuf_detach(&last_update, NULL);
+		initialize_fsmonitor_last_update(istate);
 
 		/* reset the fsmonitor state */
 		for (i = 0; i < istate->cache_nr; i++)
-- 
gitgitgadget

Re: [PATCH 01/11] p7519: use xargs -0 rather than -d in test

[Junio C Hamano]

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

> From: Jeff Hostetler <jeffhost@microsoft.com>
>
> The Mac version of xargs does not support the "-d" option.  Convert the test
> setup to pipe the data set thru `lf_to_nul | xargs -0` instead.

"xargs -0" is not all that portable, either, and neither is "touch -h".

But since the t/perf stuff already depends on having GNU toolchain
anyway, I can be persuaded to believe that it is OK.

Do we know that this part runs much later than the staged files are
last touched, so that these uses of "touch" actually are effective
to make the paths stat-dirty?  Otherwise, we may be just "touch"ing
them with the timestamp they already have after all.

Thanks.

> Signed-off-by: Jeff Hostetler <jeffhost@microsoft.com>
> ---
>  t/perf/p7519-fsmonitor.sh | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/t/perf/p7519-fsmonitor.sh b/t/perf/p7519-fsmonitor.sh
> index 9b43342806b..7bb37e9a6c1 100755
> --- a/t/perf/p7519-fsmonitor.sh
> +++ b/t/perf/p7519-fsmonitor.sh
> @@ -165,7 +165,7 @@ test_fsmonitor_suite() {
>  	'
>  
>  	test_perf_w_drop_caches "status (dirty) ($DESC)" '
> -		git ls-files | head -100000 | xargs -d "\n" touch -h &&
> +		git ls-files | head -100000 | lf_to_nul | xargs -0 touch -h &&
>  		git status
>  	'

Re: [PATCH 01/11] p7519: use xargs -0 rather than -d in test

[Jeff Hostetler]

On 2/1/21 6:25 PM, Junio C Hamano wrote:
> "Jeff Hostetler via GitGitGadget" <gitgitgadget@gmail.com> writes:
> 
>> From: Jeff Hostetler <jeffhost@microsoft.com>
>>
>> The Mac version of xargs does not support the "-d" option.  Convert the test
>> setup to pipe the data set thru `lf_to_nul | xargs -0` instead.
> 
> "xargs -0" is not all that portable, either, and neither is "touch -h".
> 
> But since the t/perf stuff already depends on having GNU toolchain
> anyway, I can be persuaded to believe that it is OK.
> 
> Do we know that this part runs much later than the staged files are
> last touched, so that these uses of "touch" actually are effective
> to make the paths stat-dirty?  Otherwise, we may be just "touch"ing
> them with the timestamp they already have after all.

I'm not sure now that you mention it.  I suppose on modern filesystems
that have mtimes with nanosecond fields we could (are) assuming that
"touch" is actually doing something.  On older filesystems (such as
FAT32), you're right it is probably not doing anything at the speed
that the test runs.

TBH I'm not sure that the test needs the "-h".  Symlinks are not that
common and it shouldn't affect the timings that much if there are a few.

I'm not sure what to do about "-0".  Not even "--null" is portable.

Let me do a little digging here.

> 
> Thanks.
> 
>> Signed-off-by: Jeff Hostetler <jeffhost@microsoft.com>
>> ---
>>   t/perf/p7519-fsmonitor.sh | 2 +-
>>   1 file changed, 1 insertion(+), 1 deletion(-)
>>
>> diff --git a/t/perf/p7519-fsmonitor.sh b/t/perf/p7519-fsmonitor.sh
>> index 9b43342806b..7bb37e9a6c1 100755
>> --- a/t/perf/p7519-fsmonitor.sh
>> +++ b/t/perf/p7519-fsmonitor.sh
>> @@ -165,7 +165,7 @@ test_fsmonitor_suite() {
>>   	'
>>   
>>   	test_perf_w_drop_caches "status (dirty) ($DESC)" '
>> -		git ls-files | head -100000 | xargs -d "\n" touch -h &&
>> +		git ls-files | head -100000 | lf_to_nul | xargs -0 touch -h &&
>>   		git status
>>   	'

Re: [PATCH 01/11] p7519: use xargs -0 rather than -d in test

[Junio C Hamano]

Jeff Hostetler <git@jeffhostetler.com> writes:

> I'm not sure now that you mention it.  I suppose on modern filesystems
> that have mtimes with nanosecond fields we could (are) assuming that
> "touch" is actually doing something.  On older filesystems (such as
> FAT32), you're right it is probably not doing anything at the speed
> that the test runs.

That one is probably the most relevant nit among the ones I raised.
I do not actually mind if we used test-chmtime to force our own
timestamp (e.g. "5 seconds before the filesystem time"), and added
the helper the "--stdin" option to read paths to work around the
"xargs" issue.

> TBH I'm not sure that the test needs the "-h".  Symlinks are not that
> common and it shouldn't affect the timings that much if there are a few.

I agree.

> I'm not sure what to do about "-0".  Not even "--null" is portable.

Correct.  I do not think it is worth "digging", though.  I do not
mind "ls-files -z | test-tool chmtime -600 --stdin -z" to lose
xargs, but we already depend on GNU time to run t/perf, and it is
not too far a stretch to require GNU xargs that knows "-0" or "-d".

Thanks.

[PATCH v2 00/11] FSMonitor Preliminary Commits

[Jeff Hostetler via GitGitGadget]

Here is version 2 of this series.

In version 1, I replaced the non-portable "xargs -d" with "xargs -0", but it
turns out that that too is not universally available. In this version I
replace the need for either one by filtering out the problematic paths (such
as ones with LFs) and quoting paths to handle whitespace. The resulting
paths can be passed to xargs without any arguments.

Also, I updated the test to use test-tool chmtime rather than touch to
ensure that the files actually look dirty on low-resolution file systems.

Jeff Hostetler (10):
  p7519: do not rely on "xargs -d" in test
  p7519: fix watchman watch-list test on Windows
  p7519: move watchman cleanup earlier in the test
  p7519: add trace logging during perf test
  preload-index: log the number of lstat calls to trace2
  read-cache: log the number of lstat calls to trace2
  read-cache: log the number of scanned files to trace2
  fsmonitor: log invocation of FSMonitor hook to trace2
  fsmonitor: log FSMN token when reading and writing the index
  fsmonitor: refactor initialization of fsmonitor_last_update token

Kevin Willford (1):
  fsmonitor: allow all entries for a folder to be invalidated

 fsmonitor.c               | 107 ++++++++++++++++++++++++++++++++++----
 fsmonitor.h               |   5 ++
 preload-index.c           |  10 ++++
 read-cache.c              |  24 +++++++--
 t/perf/.gitignore         |   1 +
 t/perf/Makefile           |   4 +-
 t/perf/p7519-fsmonitor.sh |  71 +++++++++++++++++++++----
 7 files changed, 196 insertions(+), 26 deletions(-)


base-commit: 71ca53e8125e36efbda17293c50027d31681a41f
Published-As: https://github.com/gitgitgadget/git/releases/tag/pr-860%2Fjeffhostetler%2Ffsmonitor-prework-v2
Fetch-It-Via: git fetch https://github.com/gitgitgadget/git pr-860/jeffhostetler/fsmonitor-prework-v2
Pull-Request: https://github.com/gitgitgadget/git/pull/860

Range-diff vs v1:

  1:  cf252e24b8c !  1:  e570f7316cc p7519: use xargs -0 rather than -d in test
     @@ Metadata
      Author: Jeff Hostetler <jeffhost@microsoft.com>
      
       ## Commit message ##
     -    p7519: use xargs -0 rather than -d in test
     +    p7519: do not rely on "xargs -d" in test
      
     -    The Mac version of xargs does not support the "-d" option.  Convert the test
     -    setup to pipe the data set thru `lf_to_nul | xargs -0` instead.
     +    Convert the test to use a more portable method to update the mtime on a
     +    large number of files under version control.
     +
     +    The Mac version of xargs does not support the "-d" option.
     +    Likewise, the "-0" and "--null" options are not portable.
     +
     +    Furthermore, use `test-tool chmtime` rather than `touch` to update the
     +    mtime to ensure that it is actually updated (especially on file systems
     +    with only whole second resolution).
      
          Signed-off-by: Jeff Hostetler <jeffhost@microsoft.com>
      
       ## t/perf/p7519-fsmonitor.sh ##
      @@ t/perf/p7519-fsmonitor.sh: test_fsmonitor_suite() {
     + 		git status -uall
       	'
       
     ++	# Update the mtimes on upto 100k files to make status think
     ++	# that they are dirty.  For simplicity, omit any files with
     ++	# LFs (i.e. anything that ls-files thinks it needs to dquote).
     ++	# Then fully backslash-quote the paths to capture any
     ++	# whitespace so that they pass thru xargs properly.
     ++	#
       	test_perf_w_drop_caches "status (dirty) ($DESC)" '
      -		git ls-files | head -100000 | xargs -d "\n" touch -h &&
     -+		git ls-files | head -100000 | lf_to_nul | xargs -0 touch -h &&
     ++		git ls-files | \
     ++			head -100000 | \
     ++			grep -v \" | \
     ++			sed '\''s/\(.\)/\\\1/g'\'' | \
     ++			xargs test-tool chmtime -300 &&
       		git status
       	'
       
  2:  a641f9e357c =  2:  3042fc92fe6 p7519: fix watchman watch-list test on Windows
  3:  2af6858716f =  3:  9ceba5e6942 p7519: move watchman cleanup earlier in the test
  4:  8de9985a706 =  4:  f6ea0a51f50 p7519: add trace logging during perf test
  5:  cdd49f1fdb1 =  5:  3c5035e4649 preload-index: log the number of lstat calls to trace2
  6:  65488f7a1bf =  6:  d150a2d4576 read-cache: log the number of lstat calls to trace2
  7:  c84531f6244 =  7:  33cc0b838fa read-cache: log the number of scanned files to trace2
  8:  ef64b60c7a0 =  8:  c043bccc8af fsmonitor: log invocation of FSMonitor hook to trace2
  9:  edb88ffe39e =  9:  6ec4a4468f6 fsmonitor: log FSMN token when reading and writing the index
 10:  384d2eff863 = 10:  2ac66f07a59 fsmonitor: allow all entries for a folder to be invalidated
 11:  4686196bbc6 = 11:  5410d3ab61d fsmonitor: refactor initialization of fsmonitor_last_update token

-- 
gitgitgadget

[PATCH v2 01/11] p7519: do not rely on "xargs -d" in test

[Jeff Hostetler via GitGitGadget]

From: Jeff Hostetler <jeffhost@microsoft.com>

Convert the test to use a more portable method to update the mtime on a
large number of files under version control.

The Mac version of xargs does not support the "-d" option.
Likewise, the "-0" and "--null" options are not portable.

Furthermore, use `test-tool chmtime` rather than `touch` to update the
mtime to ensure that it is actually updated (especially on file systems
with only whole second resolution).

Signed-off-by: Jeff Hostetler <jeffhost@microsoft.com>
---
 t/perf/p7519-fsmonitor.sh | 12 +++++++++++-
 1 file changed, 11 insertions(+), 1 deletion(-)

diff --git a/t/perf/p7519-fsmonitor.sh b/t/perf/p7519-fsmonitor.sh
index 9b43342806b..6677e0ef7ab 100755
--- a/t/perf/p7519-fsmonitor.sh
+++ b/t/perf/p7519-fsmonitor.sh
@@ -164,8 +164,18 @@ test_fsmonitor_suite() {
 		git status -uall
 	'
 
+	# Update the mtimes on upto 100k files to make status think
+	# that they are dirty.  For simplicity, omit any files with
+	# LFs (i.e. anything that ls-files thinks it needs to dquote).
+	# Then fully backslash-quote the paths to capture any
+	# whitespace so that they pass thru xargs properly.
+	#
 	test_perf_w_drop_caches "status (dirty) ($DESC)" '
-		git ls-files | head -100000 | xargs -d "\n" touch -h &&
+		git ls-files | \
+			head -100000 | \
+			grep -v \" | \
+			sed '\''s/\(.\)/\\\1/g'\'' | \
+			xargs test-tool chmtime -300 &&
 		git status
 	'
 
-- 
gitgitgadget

[PATCH v2 02/11] p7519: fix watchman watch-list test on Windows

[Jeff Hostetler via GitGitGadget]

From: Jeff Hostetler <jeffhost@microsoft.com>

Only use the final portion of the test trash directory file name
when verifying that Watchman was started.

On Windows and under the SDK, $GIT_WORKTREE is a cygwin-style
path with forward slashes and a "/c/" drive name.  However
`watchman watch-list` reports a proper Windows-style pathname
with drive letters and backslashes.  This causes the grep to
fail.  Since we don't really care about the full pathname (and
we really don't want to bother with normalizaing them), just see
if the test-name portion of the path is found.

Signed-off-by: Jeff Hostetler <jeffhost@microsoft.com>
---
 t/perf/p7519-fsmonitor.sh | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/t/perf/p7519-fsmonitor.sh b/t/perf/p7519-fsmonitor.sh
index 6677e0ef7ab..21d525541d5 100755
--- a/t/perf/p7519-fsmonitor.sh
+++ b/t/perf/p7519-fsmonitor.sh
@@ -101,7 +101,7 @@ test_expect_success "one time repo setup" '
 	# If Watchman exists, watch the work tree and attempt a query.
 	if test_have_prereq WATCHMAN; then
 		watchman watch "$GIT_WORK_TREE" &&
-		watchman watch-list | grep -q -F "$GIT_WORK_TREE"
+		watchman watch-list | grep -q -F "p7519-fsmonitor"
 	fi
 '
 
-- 
gitgitgadget

[PATCH v2 03/11] p7519: move watchman cleanup earlier in the test

[Jeff Hostetler via GitGitGadget]

From: Jeff Hostetler <jeffhost@microsoft.com>

Shutdown Watchman after the Watchman-based tests and before the block of
"no fsmonitor" tests.

This helps ensure that Watchman cannot affect the test results for the
other.

Signed-off-by: Jeff Hostetler <jeffhost@microsoft.com>
---
 t/perf/p7519-fsmonitor.sh | 25 +++++++++++++++++--------
 1 file changed, 17 insertions(+), 8 deletions(-)

diff --git a/t/perf/p7519-fsmonitor.sh b/t/perf/p7519-fsmonitor.sh
index 21d525541d5..78e7d2c03f5 100755
--- a/t/perf/p7519-fsmonitor.sh
+++ b/t/perf/p7519-fsmonitor.sh
@@ -208,6 +208,11 @@ test_fsmonitor_suite() {
 	'
 }
 
+#
+# Run a full set of perf tests using each Hook-based fsmonitor provider,
+# such as Watchman.
+#
+
 if test -n "$GIT_PERF_7519_FSMONITOR"; then
 	for INTEGRATION_PATH in $GIT_PERF_7519_FSMONITOR; do
 		test_expect_success "setup for fsmonitor $INTEGRATION_PATH" 'setup_for_fsmonitor'
@@ -218,14 +223,6 @@ else
 	test_fsmonitor_suite
 fi
 
-test_expect_success "setup without fsmonitor" '
-	unset INTEGRATION_SCRIPT &&
-	git config --unset core.fsmonitor &&
-	git update-index --no-fsmonitor
-'
-
-test_fsmonitor_suite
-
 if test_have_prereq WATCHMAN
 then
 	watchman watch-del "$GIT_WORK_TREE" >/dev/null 2>&1 &&
@@ -235,4 +232,16 @@ then
 	watchman shutdown-server >/dev/null 2>&1
 fi
 
+#
+# Run a full set of perf tests with the fsmonitor feature disabled.
+#
+
+test_expect_success "setup without fsmonitor" '
+	unset INTEGRATION_SCRIPT &&
+	git config --unset core.fsmonitor &&
+	git update-index --no-fsmonitor
+'
+
+test_fsmonitor_suite
+
 test_done
-- 
gitgitgadget

[PATCH v2 04/11] p7519: add trace logging during perf test

[Jeff Hostetler via GitGitGadget]

From: Jeff Hostetler <jeffhost@microsoft.com>

Add optional trace logging to allow us to better compare performance of
various fsmonitor providers and compare results with non-fsmonitor runs.

Currently, this includes Trace2 logging, but may be extended to include
other trace targets, such as GIT_TRACE_FSMONITOR if desired.

Using this logging helped me explain an odd behavior on MacOS where the
kernel was dropping events and causing the hook to Watchman to timeout.

Signed-off-by: Jeff Hostetler <jeffhost@microsoft.com>
---
 t/perf/.gitignore         |  1 +
 t/perf/Makefile           |  4 ++--
 t/perf/p7519-fsmonitor.sh | 32 ++++++++++++++++++++++++++++++++
 3 files changed, 35 insertions(+), 2 deletions(-)

diff --git a/t/perf/.gitignore b/t/perf/.gitignore
index 982eb8e3a94..72f5d0d3148 100644
--- a/t/perf/.gitignore
+++ b/t/perf/.gitignore
@@ -1,3 +1,4 @@
 /build/
 /test-results/
+/test-trace/
 /trash directory*/
diff --git a/t/perf/Makefile b/t/perf/Makefile
index fcb0e8865e4..2465770a782 100644
--- a/t/perf/Makefile
+++ b/t/perf/Makefile
@@ -7,10 +7,10 @@ perf: pre-clean
 	./run
 
 pre-clean:
-	rm -rf test-results
+	rm -rf test-results test-trace
 
 clean:
-	rm -rf build "trash directory".* test-results
+	rm -rf build "trash directory".* test-results test-trace
 
 test-lint:
 	$(MAKE) -C .. test-lint
diff --git a/t/perf/p7519-fsmonitor.sh b/t/perf/p7519-fsmonitor.sh
index 78e7d2c03f5..aa0ea0e2ec8 100755
--- a/t/perf/p7519-fsmonitor.sh
+++ b/t/perf/p7519-fsmonitor.sh
@@ -32,6 +32,8 @@ test_description="Test core.fsmonitor"
 #
 # GIT_PERF_7519_DROP_CACHE: if set, the OS caches are dropped between tests
 #
+# GIT_PERF_7519_TRACE: if set, enable trace logging during the test.
+#   Trace logs will be grouped by fsmonitor provider.
 
 test_perf_large_repo
 test_checkout_worktree
@@ -70,6 +72,32 @@ then
 	fi
 fi
 
+trace_start() {
+	if test -n "$GIT_PERF_7519_TRACE"
+	then
+		name="$1"
+		TEST_TRACE_DIR="$TEST_OUTPUT_DIRECTORY/test-trace/p7519/"
+		echo "Writing trace logging to $TEST_TRACE_DIR"
+
+		mkdir -p "$TEST_TRACE_DIR"
+
+		# Start Trace2 logging and any other GIT_TRACE_* logs that you
+		# want for this named test case.
+
+		GIT_TRACE2_PERF="$TEST_TRACE_DIR/$name.trace2perf"
+		export GIT_TRACE2_PERF
+
+		>"$GIT_TRACE2_PERF"
+	fi
+}
+
+trace_stop() {
+	if test -n "$GIT_PERF_7519_TRACE"
+	then
+		unset GIT_TRACE2_PERF
+	fi
+}
+
 test_expect_success "one time repo setup" '
 	# set untrackedCache depending on the environment
 	if test -n "$GIT_PERF_7519_UNTRACKED_CACHE"
@@ -213,6 +241,7 @@ test_fsmonitor_suite() {
 # such as Watchman.
 #
 
+trace_start fsmonitor-watchman
 if test -n "$GIT_PERF_7519_FSMONITOR"; then
 	for INTEGRATION_PATH in $GIT_PERF_7519_FSMONITOR; do
 		test_expect_success "setup for fsmonitor $INTEGRATION_PATH" 'setup_for_fsmonitor'
@@ -231,11 +260,13 @@ then
 	# preventing the removal of the trash directory
 	watchman shutdown-server >/dev/null 2>&1
 fi
+trace_stop
 
 #
 # Run a full set of perf tests with the fsmonitor feature disabled.
 #
 
+trace_start fsmonitor-disabled
 test_expect_success "setup without fsmonitor" '
 	unset INTEGRATION_SCRIPT &&
 	git config --unset core.fsmonitor &&
@@ -243,5 +274,6 @@ test_expect_success "setup without fsmonitor" '
 '
 
 test_fsmonitor_suite
+trace_stop
 
 test_done
-- 
gitgitgadget

[PATCH v2 05/11] preload-index: log the number of lstat calls to trace2

[Jeff Hostetler via GitGitGadget]

From: Jeff Hostetler <jeffhost@microsoft.com>

Report the total number of calls made to lstat() inside preload_index().

FSMonitor improves the performance of commands like `git status` by
avoiding scanning the disk for changed files.  This can be seen in
`preload_index()`.  Let's measure this.

Signed-off-by: Jeff Hostetler <jeffhost@microsoft.com>
---
 preload-index.c | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/preload-index.c b/preload-index.c
index ed6eaa47388..e5529a58636 100644
--- a/preload-index.c
+++ b/preload-index.c
@@ -31,6 +31,7 @@ struct thread_data {
 	struct pathspec pathspec;
 	struct progress_data *progress;
 	int offset, nr;
+	int t2_nr_lstat;
 };
 
 static void *preload_thread(void *_data)
@@ -73,6 +74,7 @@ static void *preload_thread(void *_data)
 			continue;
 		if (threaded_has_symlink_leading_path(&cache, ce->name, ce_namelen(ce)))
 			continue;
+		p->t2_nr_lstat++;
 		if (lstat(ce->name, &st))
 			continue;
 		if (ie_match_stat(index, ce, &st, CE_MATCH_RACY_IS_DIRTY|CE_MATCH_IGNORE_FSMONITOR))
@@ -98,6 +100,7 @@ void preload_index(struct index_state *index,
 	int threads, i, work, offset;
 	struct thread_data data[MAX_PARALLEL];
 	struct progress_data pd;
+	int t2_sum_lstat = 0;
 
 	if (!HAVE_THREADS || !core_preload_index)
 		return;
@@ -107,6 +110,9 @@ void preload_index(struct index_state *index,
 		threads = 2;
 	if (threads < 2)
 		return;
+
+	trace2_region_enter("index", "preload", NULL);
+
 	trace_performance_enter();
 	if (threads > MAX_PARALLEL)
 		threads = MAX_PARALLEL;
@@ -141,10 +147,14 @@ void preload_index(struct index_state *index,
 		struct thread_data *p = data+i;
 		if (pthread_join(p->pthread, NULL))
 			die("unable to join threaded lstat");
+		t2_sum_lstat += p->t2_nr_lstat;
 	}
 	stop_progress(&pd.progress);
 
 	trace_performance_leave("preload index");
+
+	trace2_data_intmax("index", NULL, "preload/sum_lstat", t2_sum_lstat);
+	trace2_region_leave("index", "preload", NULL);
 }
 
 int repo_read_index_preload(struct repository *repo,
-- 
gitgitgadget

[PATCH v2 06/11] read-cache: log the number of lstat calls to trace2

[Jeff Hostetler via GitGitGadget]

From: Jeff Hostetler <jeffhost@microsoft.com>

Report the total number of calls made to lstat() inside of refresh_index().

FSMonitor improves the performance of commands like `git status` by
avoiding scanning the disk for changed files.  This can be seen in
`refresh_index()`.  Let's measure this.

Signed-off-by: Jeff Hostetler <jeffhost@microsoft.com>
---
 read-cache.c | 17 ++++++++++++++---
 1 file changed, 14 insertions(+), 3 deletions(-)

diff --git a/read-cache.c b/read-cache.c
index ecf6f689940..893cc41e1d9 100644
--- a/read-cache.c
+++ b/read-cache.c
@@ -1364,7 +1364,8 @@ int add_index_entry(struct index_state *istate, struct cache_entry *ce, int opti
 static struct cache_entry *refresh_cache_ent(struct index_state *istate,
 					     struct cache_entry *ce,
 					     unsigned int options, int *err,
-					     int *changed_ret)
+					     int *changed_ret,
+					     int *t2_did_lstat)
 {
 	struct stat st;
 	struct cache_entry *updated;
@@ -1406,6 +1407,8 @@ static struct cache_entry *refresh_cache_ent(struct index_state *istate,
 		return NULL;
 	}
 
+	if (t2_did_lstat)
+		*t2_did_lstat = 1;
 	if (lstat(ce->name, &st) < 0) {
 		if (ignore_missing && errno == ENOENT)
 			return ce;
@@ -1519,6 +1522,7 @@ int refresh_index(struct index_state *istate, unsigned int flags,
 	const char *added_fmt;
 	const char *unmerged_fmt;
 	struct progress *progress = NULL;
+	int t2_sum_lstat = 0;
 
 	if (flags & REFRESH_PROGRESS && isatty(2))
 		progress = start_delayed_progress(_("Refresh index"),
@@ -1536,11 +1540,13 @@ int refresh_index(struct index_state *istate, unsigned int flags,
 	 * we only have to do the special cases that are left.
 	 */
 	preload_index(istate, pathspec, 0);
+	trace2_region_enter("index", "refresh", NULL);
 	for (i = 0; i < istate->cache_nr; i++) {
 		struct cache_entry *ce, *new_entry;
 		int cache_errno = 0;
 		int changed = 0;
 		int filtered = 0;
+		int t2_did_lstat = 0;
 
 		ce = istate->cache[i];
 		if (ignore_submodules && S_ISGITLINK(ce->ce_mode))
@@ -1566,7 +1572,10 @@ int refresh_index(struct index_state *istate, unsigned int flags,
 		if (filtered)
 			continue;
 
-		new_entry = refresh_cache_ent(istate, ce, options, &cache_errno, &changed);
+		new_entry = refresh_cache_ent(istate, ce, options,
+					      &cache_errno, &changed,
+					      &t2_did_lstat);
+		t2_sum_lstat += t2_did_lstat;
 		if (new_entry == ce)
 			continue;
 		if (progress)
@@ -1602,6 +1611,8 @@ int refresh_index(struct index_state *istate, unsigned int flags,
 
 		replace_index_entry(istate, i, new_entry);
 	}
+	trace2_data_intmax("index", NULL, "refresh/sum_lstat", t2_sum_lstat);
+	trace2_region_leave("index", "refresh", NULL);
 	if (progress) {
 		display_progress(progress, istate->cache_nr);
 		stop_progress(&progress);
@@ -1614,7 +1625,7 @@ struct cache_entry *refresh_cache_entry(struct index_state *istate,
 					struct cache_entry *ce,
 					unsigned int options)
 {
-	return refresh_cache_ent(istate, ce, options, NULL, NULL);
+	return refresh_cache_ent(istate, ce, options, NULL, NULL, NULL);
 }
 
 
-- 
gitgitgadget

[PATCH v2 07/11] read-cache: log the number of scanned files to trace2

[Jeff Hostetler via GitGitGadget]

From: Jeff Hostetler <jeffhost@microsoft.com>

Report the number of files in the working directory that were read and
their hashes verified in `refresh_index()`.

FSMonitor improves the performance of commands like `git status` by
avoiding scanning the disk for changed files.  Let's measure this.

Signed-off-by: Jeff Hostetler <jeffhost@microsoft.com>
---
 read-cache.c | 13 ++++++++++---
 1 file changed, 10 insertions(+), 3 deletions(-)

diff --git a/read-cache.c b/read-cache.c
index 893cc41e1d9..c9dd7f4015e 100644
--- a/read-cache.c
+++ b/read-cache.c
@@ -1365,7 +1365,8 @@ static struct cache_entry *refresh_cache_ent(struct index_state *istate,
 					     struct cache_entry *ce,
 					     unsigned int options, int *err,
 					     int *changed_ret,
-					     int *t2_did_lstat)
+					     int *t2_did_lstat,
+					     int *t2_did_scan)
 {
 	struct stat st;
 	struct cache_entry *updated;
@@ -1445,6 +1446,8 @@ static struct cache_entry *refresh_cache_ent(struct index_state *istate,
 		}
 	}
 
+	if (t2_did_scan)
+		*t2_did_scan = 1;
 	if (ie_modified(istate, ce, &st, options)) {
 		if (err)
 			*err = EINVAL;
@@ -1523,6 +1526,7 @@ int refresh_index(struct index_state *istate, unsigned int flags,
 	const char *unmerged_fmt;
 	struct progress *progress = NULL;
 	int t2_sum_lstat = 0;
+	int t2_sum_scan = 0;
 
 	if (flags & REFRESH_PROGRESS && isatty(2))
 		progress = start_delayed_progress(_("Refresh index"),
@@ -1547,6 +1551,7 @@ int refresh_index(struct index_state *istate, unsigned int flags,
 		int changed = 0;
 		int filtered = 0;
 		int t2_did_lstat = 0;
+		int t2_did_scan = 0;
 
 		ce = istate->cache[i];
 		if (ignore_submodules && S_ISGITLINK(ce->ce_mode))
@@ -1574,8 +1579,9 @@ int refresh_index(struct index_state *istate, unsigned int flags,
 
 		new_entry = refresh_cache_ent(istate, ce, options,
 					      &cache_errno, &changed,
-					      &t2_did_lstat);
+					      &t2_did_lstat, &t2_did_scan);
 		t2_sum_lstat += t2_did_lstat;
+		t2_sum_scan += t2_did_scan;
 		if (new_entry == ce)
 			continue;
 		if (progress)
@@ -1612,6 +1618,7 @@ int refresh_index(struct index_state *istate, unsigned int flags,
 		replace_index_entry(istate, i, new_entry);
 	}
 	trace2_data_intmax("index", NULL, "refresh/sum_lstat", t2_sum_lstat);
+	trace2_data_intmax("index", NULL, "refresh/sum_scan", t2_sum_scan);
 	trace2_region_leave("index", "refresh", NULL);
 	if (progress) {
 		display_progress(progress, istate->cache_nr);
@@ -1625,7 +1632,7 @@ struct cache_entry *refresh_cache_entry(struct index_state *istate,
 					struct cache_entry *ce,
 					unsigned int options)
 {
-	return refresh_cache_ent(istate, ce, options, NULL, NULL, NULL);
+	return refresh_cache_ent(istate, ce, options, NULL, NULL, NULL, NULL);
 }
 
 
-- 
gitgitgadget

[PATCH v2 08/11] fsmonitor: log invocation of FSMonitor hook to trace2

[Jeff Hostetler via GitGitGadget]

From: Jeff Hostetler <jeffhost@microsoft.com>

Let's measure the time taken to request and receive FSMonitor data
via the hook API and the size of the response.

Signed-off-by: Jeff Hostetler <jeffhost@microsoft.com>
---
 fsmonitor.c | 29 ++++++++++++++++++++++++++++-
 fsmonitor.h |  5 +++++
 2 files changed, 33 insertions(+), 1 deletion(-)

diff --git a/fsmonitor.c b/fsmonitor.c
index ca031c3abb8..7a2be24cd43 100644
--- a/fsmonitor.c
+++ b/fsmonitor.c
@@ -142,6 +142,7 @@ void write_fsmonitor_extension(struct strbuf *sb, struct index_state *istate)
 static int query_fsmonitor(int version, const char *last_update, struct strbuf *query_result)
 {
 	struct child_process cp = CHILD_PROCESS_INIT;
+	int result;
 
 	if (!core_fsmonitor)
 		return -1;
@@ -152,7 +153,33 @@ static int query_fsmonitor(int version, const char *last_update, struct strbuf *
 	cp.use_shell = 1;
 	cp.dir = get_git_work_tree();
 
-	return capture_command(&cp, query_result, 1024);
+	trace2_region_enter("fsm_hook", "query", NULL);
+
+	result = capture_command(&cp, query_result, 1024);
+
+	if (result)
+		trace2_data_intmax("fsm_hook", NULL, "query/failed", result);
+	else {
+		trace2_data_intmax("fsm_hook", NULL, "query/response-length",
+				   query_result->len);
+
+		if (fsmonitor_is_trivial_response(query_result))
+			trace2_data_intmax("fsm_hook", NULL,
+					   "query/trivial-response", 1);
+	}
+
+	trace2_region_leave("fsm_hook", "query", NULL);
+
+	return result;
+}
+
+int fsmonitor_is_trivial_response(const struct strbuf *query_result)
+{
+	static char trivial_response[3] = { '\0', '/', '\0' };
+	int is_trivial = !memcmp(trivial_response,
+				 &query_result->buf[query_result->len - 3], 3);
+
+	return is_trivial;
 }
 
 static void fsmonitor_refresh_callback(struct index_state *istate, const char *name)
diff --git a/fsmonitor.h b/fsmonitor.h
index 739318ab6d1..7f1794b90b0 100644
--- a/fsmonitor.h
+++ b/fsmonitor.h
@@ -44,6 +44,11 @@ void tweak_fsmonitor(struct index_state *istate);
  */
 void refresh_fsmonitor(struct index_state *istate);
 
+/*
+ * Does the received result contain the "trivial" response?
+ */
+int fsmonitor_is_trivial_response(const struct strbuf *query_result);
+
 /*
  * Set the given cache entries CE_FSMONITOR_VALID bit. This should be
  * called any time the cache entry has been updated to reflect the
-- 
gitgitgadget

[PATCH v2 09/11] fsmonitor: log FSMN token when reading and writing the index

[Jeff Hostetler via GitGitGadget]

From: Jeff Hostetler <jeffhost@microsoft.com>

Signed-off-by: Jeff Hostetler <jeffhost@microsoft.com>
---
 fsmonitor.c | 12 ++++++++++--
 1 file changed, 10 insertions(+), 2 deletions(-)

diff --git a/fsmonitor.c b/fsmonitor.c
index 7a2be24cd43..3105dc370ab 100644
--- a/fsmonitor.c
+++ b/fsmonitor.c
@@ -87,7 +87,11 @@ int read_fsmonitor_extension(struct index_state *istate, const void *data,
 		BUG("fsmonitor_dirty has more entries than the index (%"PRIuMAX" > %u)",
 		    (uintmax_t)istate->fsmonitor_dirty->bit_size, istate->cache_nr);
 
-	trace_printf_key(&trace_fsmonitor, "read fsmonitor extension successful");
+	trace2_data_string("index", NULL, "extension/fsmn/read/token",
+			   istate->fsmonitor_last_update);
+	trace_printf_key(&trace_fsmonitor,
+			 "read fsmonitor extension successful '%s'",
+			 istate->fsmonitor_last_update);
 	return 0;
 }
 
@@ -133,7 +137,11 @@ void write_fsmonitor_extension(struct strbuf *sb, struct index_state *istate)
 	put_be32(&ewah_size, sb->len - ewah_start);
 	memcpy(sb->buf + fixup, &ewah_size, sizeof(uint32_t));
 
-	trace_printf_key(&trace_fsmonitor, "write fsmonitor extension successful");
+	trace2_data_string("index", NULL, "extension/fsmn/write/token",
+			   istate->fsmonitor_last_update);
+	trace_printf_key(&trace_fsmonitor,
+			 "write fsmonitor extension successful '%s'",
+			 istate->fsmonitor_last_update);
 }
 
 /*
-- 
gitgitgadget

[PATCH v2 10/11] fsmonitor: allow all entries for a folder to be invalidated

[Kevin Willford via GitGitGadget]

From: Kevin Willford <Kevin.Willford@microsoft.com>

Allow fsmonitor to report directory changes by reporting paths with a
trailing slash.

Signed-off-by: Jeff Hostetler <jeffhost@microsoft.com>
Signed-off-by: Kevin Willford <Kevin.Willford@microsoft.com>
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
---
 fsmonitor.c | 31 ++++++++++++++++++++++++++-----
 1 file changed, 26 insertions(+), 5 deletions(-)

diff --git a/fsmonitor.c b/fsmonitor.c
index 3105dc370ab..64deeda597e 100644
--- a/fsmonitor.c
+++ b/fsmonitor.c
@@ -190,13 +190,34 @@ int fsmonitor_is_trivial_response(const struct strbuf *query_result)
 	return is_trivial;
 }
 
-static void fsmonitor_refresh_callback(struct index_state *istate, const char *name)
+static void fsmonitor_refresh_callback(struct index_state *istate, char *name)
 {
-	int pos = index_name_pos(istate, name, strlen(name));
+	int i, len = strlen(name);
+	if (name[len - 1] == '/') {
+
+		/*
+		 * TODO We should binary search to find the first path with
+		 * TODO this directory prefix.  Then linearly update entries
+		 * TODO while the prefix matches.  Taking care to search without
+		 * TODO the trailing slash -- because '/' sorts after a few
+		 * TODO interesting special chars, like '.' and ' '.
+		 */
+
+		/* Mark all entries for the folder invalid */
+		for (i = 0; i < istate->cache_nr; i++) {
+			if (istate->cache[i]->ce_flags & CE_FSMONITOR_VALID &&
+			    starts_with(istate->cache[i]->name, name))
+				istate->cache[i]->ce_flags &= ~CE_FSMONITOR_VALID;
+		}
+		/* Need to remove the / from the path for the untracked cache */
+		name[len - 1] = '\0';
+	} else {
+		int pos = index_name_pos(istate, name, strlen(name));
 
-	if (pos >= 0) {
-		struct cache_entry *ce = istate->cache[pos];
-		ce->ce_flags &= ~CE_FSMONITOR_VALID;
+		if (pos >= 0) {
+			struct cache_entry *ce = istate->cache[pos];
+			ce->ce_flags &= ~CE_FSMONITOR_VALID;
+		}
 	}
 
 	/*
-- 
gitgitgadget

[PATCH v2 11/11] fsmonitor: refactor initialization of fsmonitor_last_update token

[Jeff Hostetler via GitGitGadget]

From: Jeff Hostetler <jeffhost@microsoft.com>

Isolate and document initialization of `istate->fsmonitor_last_update`.
This field should contain a fsmonitor-specific opaque token, but we
need to initialize it before we can actually talk to a fsmonitor process,
so we create a generic default value.

Signed-off-by: Jeff Hostetler <jeffhost@microsoft.com>
---
 fsmonitor.c | 35 ++++++++++++++++++++++++++++++++---
 1 file changed, 32 insertions(+), 3 deletions(-)

diff --git a/fsmonitor.c b/fsmonitor.c
index 64deeda597e..e12214b3007 100644
--- a/fsmonitor.c
+++ b/fsmonitor.c
@@ -343,16 +343,45 @@ void refresh_fsmonitor(struct index_state *istate)
 	istate->fsmonitor_last_update = strbuf_detach(&last_update_token, NULL);
 }
 
+/*
+ * The caller wants to turn on FSMonitor.  And when the caller writes
+ * the index to disk, a FSMonitor extension should be included.  This
+ * requires that `istate->fsmonitor_last_update` not be NULL.  But we
+ * have not actually talked to a FSMonitor process yet, so we don't
+ * have an initial value for this field.
+ *
+ * For a protocol V1 FSMonitor process, this field is a formatted
+ * "nanoseconds since epoch" field.  However, for a protocol V2
+ * FSMonitor process, this field is an opaque token.
+ *
+ * Historically, `add_fsmonitor()` has initialized this field to the
+ * current time for protocol V1 processes.  There are lots of race
+ * conditions here, but that code has shipped...
+ *
+ * The only true solution is to use a V2 FSMonitor and get a current
+ * or default token value (that it understands), but we cannot do that
+ * until we have actually talked to an instance of the FSMonitor process
+ * (but the protocol requires that we send a token first...).
+ *
+ * For simplicity, just initialize like we have a V1 process and require
+ * that V2 processes adapt.
+ */
+static void initialize_fsmonitor_last_update(struct index_state *istate)
+{
+	struct strbuf last_update = STRBUF_INIT;
+
+	strbuf_addf(&last_update, "%"PRIu64"", getnanotime());
+	istate->fsmonitor_last_update = strbuf_detach(&last_update, NULL);
+}
+
 void add_fsmonitor(struct index_state *istate)
 {
 	unsigned int i;
-	struct strbuf last_update = STRBUF_INIT;
 
 	if (!istate->fsmonitor_last_update) {
 		trace_printf_key(&trace_fsmonitor, "add fsmonitor");
 		istate->cache_changed |= FSMONITOR_CHANGED;
-		strbuf_addf(&last_update, "%"PRIu64"", getnanotime());
-		istate->fsmonitor_last_update = strbuf_detach(&last_update, NULL);
+		initialize_fsmonitor_last_update(istate);
 
 		/* reset the fsmonitor state */
 		for (i = 0; i < istate->cache_nr; i++)
-- 
gitgitgadget

Re: [PATCH 00/11] FSMonitor Preliminary Commits

[Taylor Blau]

Hi Jeff,

On Mon, Feb 01, 2021 at 10:02:09PM +0000, Jeff Hostetler via GitGitGadget wrote:
> This patch series fixes runtime errors in t/perf/p7519 on Windows and MacOS.
> It adds Trace2 logging to p7519 to make it easier to compare results when
> Watchman is enabled and disabled. And finally, it adds some Trace2 regions
> and data events around our usage of Watchman and the existing FSMonitor
> framework.

I read v2 of this series and it all looked very sane to me. I didn't
have much in the way of comments or concerns along the way, so that
version of the series has my reviewed-by.

Thanks,
Taylor

Re: [PATCH v2 00/11] FSMonitor Preliminary Commits

[Jeff Hostetler]

On 2/3/21 10:34 AM, Jeff Hostetler via GitGitGadget wrote:
> Here is version 2 of this series.

I didn't see this series in the "what's cooking" emails and
was wondering if there was something that I still needed to
attend to.

Thanks
Jeff


> 
> In version 1, I replaced the non-portable "xargs -d" with "xargs -0", but it
> turns out that that too is not universally available. In this version I
> replace the need for either one by filtering out the problematic paths (such
> as ones with LFs) and quoting paths to handle whitespace. The resulting
> paths can be passed to xargs without any arguments.
> 
> Also, I updated the test to use test-tool chmtime rather than touch to
> ensure that the files actually look dirty on low-resolution file systems.
> 
> Jeff Hostetler (10):
>    p7519: do not rely on "xargs -d" in test
>    p7519: fix watchman watch-list test on Windows
>    p7519: move watchman cleanup earlier in the test
>    p7519: add trace logging during perf test
>    preload-index: log the number of lstat calls to trace2
>    read-cache: log the number of lstat calls to trace2
>    read-cache: log the number of scanned files to trace2
>    fsmonitor: log invocation of FSMonitor hook to trace2
>    fsmonitor: log FSMN token when reading and writing the index
>    fsmonitor: refactor initialization of fsmonitor_last_update token
> 
> Kevin Willford (1):
>    fsmonitor: allow all entries for a folder to be invalidated
> 
>   fsmonitor.c               | 107 ++++++++++++++++++++++++++++++++++----
>   fsmonitor.h               |   5 ++
>   preload-index.c           |  10 ++++
>   read-cache.c              |  24 +++++++--
>   t/perf/.gitignore         |   1 +
>   t/perf/Makefile           |   4 +-
>   t/perf/p7519-fsmonitor.sh |  71 +++++++++++++++++++++----
>   7 files changed, 196 insertions(+), 26 deletions(-)
> 
> 
> base-commit: 71ca53e8125e36efbda17293c50027d31681a41f
> Published-As: https://github.com/gitgitgadget/git/releases/tag/pr-860%2Fjeffhostetler%2Ffsmonitor-prework-v2
> Fetch-It-Via: git fetch https://github.com/gitgitgadget/git pr-860/jeffhostetler/fsmonitor-prework-v2
> Pull-Request: https://github.com/gitgitgadget/git/pull/860
> 
> Range-diff vs v1:
> 
>    1:  cf252e24b8c !  1:  e570f7316cc p7519: use xargs -0 rather than -d in test
>       @@ Metadata
>        Author: Jeff Hostetler <jeffhost@microsoft.com>
>        
>         ## Commit message ##
>       -    p7519: use xargs -0 rather than -d in test
>       +    p7519: do not rely on "xargs -d" in test
>        
>       -    The Mac version of xargs does not support the "-d" option.  Convert the test
>       -    setup to pipe the data set thru `lf_to_nul | xargs -0` instead.
>       +    Convert the test to use a more portable method to update the mtime on a
>       +    large number of files under version control.
>       +
>       +    The Mac version of xargs does not support the "-d" option.
>       +    Likewise, the "-0" and "--null" options are not portable.
>       +
>       +    Furthermore, use `test-tool chmtime` rather than `touch` to update the
>       +    mtime to ensure that it is actually updated (especially on file systems
>       +    with only whole second resolution).
>        
>            Signed-off-by: Jeff Hostetler <jeffhost@microsoft.com>
>        
>         ## t/perf/p7519-fsmonitor.sh ##
>        @@ t/perf/p7519-fsmonitor.sh: test_fsmonitor_suite() {
>       + 		git status -uall
>         	'
>         
>       ++	# Update the mtimes on upto 100k files to make status think
>       ++	# that they are dirty.  For simplicity, omit any files with
>       ++	# LFs (i.e. anything that ls-files thinks it needs to dquote).
>       ++	# Then fully backslash-quote the paths to capture any
>       ++	# whitespace so that they pass thru xargs properly.
>       ++	#
>         	test_perf_w_drop_caches "status (dirty) ($DESC)" '
>        -		git ls-files | head -100000 | xargs -d "\n" touch -h &&
>       -+		git ls-files | head -100000 | lf_to_nul | xargs -0 touch -h &&
>       ++		git ls-files | \
>       ++			head -100000 | \
>       ++			grep -v \" | \
>       ++			sed '\''s/\(.\)/\\\1/g'\'' | \
>       ++			xargs test-tool chmtime -300 &&
>         		git status
>         	'
>         
>    2:  a641f9e357c =  2:  3042fc92fe6 p7519: fix watchman watch-list test on Windows
>    3:  2af6858716f =  3:  9ceba5e6942 p7519: move watchman cleanup earlier in the test
>    4:  8de9985a706 =  4:  f6ea0a51f50 p7519: add trace logging during perf test
>    5:  cdd49f1fdb1 =  5:  3c5035e4649 preload-index: log the number of lstat calls to trace2
>    6:  65488f7a1bf =  6:  d150a2d4576 read-cache: log the number of lstat calls to trace2
>    7:  c84531f6244 =  7:  33cc0b838fa read-cache: log the number of scanned files to trace2
>    8:  ef64b60c7a0 =  8:  c043bccc8af fsmonitor: log invocation of FSMonitor hook to trace2
>    9:  edb88ffe39e =  9:  6ec4a4468f6 fsmonitor: log FSMN token when reading and writing the index
>   10:  384d2eff863 = 10:  2ac66f07a59 fsmonitor: allow all entries for a folder to be invalidated
>   11:  4686196bbc6 = 11:  5410d3ab61d fsmonitor: refactor initialization of fsmonitor_last_update token
> 

Re: [PATCH v2 00/11] FSMonitor Preliminary Commits

[Junio C Hamano]

Jeff Hostetler <git@jeffhostetler.com> writes:

> On 2/3/21 10:34 AM, Jeff Hostetler via GitGitGadget wrote:
>> Here is version 2 of this series.
>
> I didn't see this series in the "what's cooking" emails and
> was wondering if there was something that I still needed to
> attend to.

I think it fell through the cracks.  It seems that Taylor gave a
reviewed-by for the whole set in v2 but as a reply to the cover
letter of the original series, and no messages in v2 saw any
comments.

I just picked them up and queued.  Thanks for pinging.