From: Phillip Wood <phillip.wood123@gmail.com>
To: "Ævar Arnfjörð Bjarmason" <avarab@gmail.com>, git@vger.kernel.org
Cc: "Junio C Hamano" <gitster@pobox.com>, "Jeff King" <peff@peff.net>,
"Dan Jacques" <dnj@google.com>, "Eric Wong" <e@80x24.org>,
"Jonathan Nieder" <jrnieder@gmail.com>,
"Mike Hommey" <mh@glandium.org>,
"Đoàn Trần Công Danh" <congdanhqx@gmail.com>,
"Victoria Dye" <vdye@github.com>,
"Eric Sunshine" <sunshine@sunshineco.com>,
"Taylor Blau" <me@ttaylorr.com>
Subject: Re: [PATCH v4 0/9] Makefile: optimize noop runs, add shared.mak
Date: Thu, 3 Mar 2022 14:08:45 +0000 [thread overview]
Message-ID: <d75f5bed-ce2e-19fd-5913-b6272132a6cb@gmail.com> (raw)
In-Reply-To: <cover-v4-0.9-00000000000-20220302T124320Z-avarab@gmail.com>
On 02/03/2022 12:49, Ævar Arnfjörð Bjarmason wrote:
> As the v1 notes (among other things):
> https://lore.kernel.org/git/cover-0.8-00000000000-20211217T012902Z-avarab@gmail.com/
>
> This speeds up noop runs of "make" by a lot. After a "make" running a
> "make -j1" with this is ~1.5 faster than on "master"[2], and around 3x
> as fast with "make -j1 NO_TCLTK=Y" (the TCL part takes a lot of time,
> but that's another matter).
>
> This v4 re-roll (for v3, see
> https://lore.kernel.org/git/cover-v3-0.9-00000000000-20220225T090127Z-avarab@gmail.com/):
>
> * The "all" boilerplate goes first now, before "include"
> * Elaborated on DELETE_ON_ERROR ina commit message.
> * No longer change a ":=" to "=" while moving code.
> * Rephrased other commit messages (one of which referred to a
> function from another future series)
> * Typo fix in commit message.
>
> Ævar Arnfjörð Bjarmason (9):
> scalar Makefile: use "The default target of..." pattern
> Makefiles: add "shared.mak", move ".DELETE_ON_ERROR" to it
> Makefile: disable GNU make built-in wildcard rules
> Makefile: define $(LIB_H) in terms of $(FIND_SOURCE_FILES)
> Makefile: move ".SUFFIXES" rule to shared.mak
> Makefile: move $(comma), $(empty) and $(space) to shared.mak
> Makefile: add "$(QUIET)" boilerplate to shared.mak
> Makefile: use $(wspfx) for $(QUIET...) in shared.mak
> Makefiles: add and use wildcard "mkdir -p" template
>
> Documentation/Makefile | 63 ++------------------
> Makefile | 118 ++++++++++++--------------------------
> config.mak.uname | 1 -
> contrib/scalar/Makefile | 20 ++-----
> contrib/scalar/t/Makefile | 3 +
> shared.mak | 109 +++++++++++++++++++++++++++++++++++
> t/Makefile | 3 +
> t/interop/Makefile | 3 +
> t/perf/Makefile | 3 +
> templates/Makefile | 8 +--
> 10 files changed, 171 insertions(+), 160 deletions(-)
> create mode 100644 shared.mak
>
> Range-diff against v3:
> 1: 2404c4d8b96 < -: ----------- scalar Makefile: set the default target after the includes
> -: ----------- > 1: 26c6bb897cf scalar Makefile: use "The default target of..." pattern
> 2: 96a490bec54 ! 2: 74692458b70 Makefiles: add "shared.mak", move ".DELETE_ON_ERROR" to it
> @@ Commit message
> .DELETE_ON_ERROR, 2021-05-21) for the addition and use of the
> ".DELETE_ON_ERROR" flag.
>
> - This does have the potential downside that if e.g. templates/Makefile
> - would like to include this "shared.mak" in the future the semantics of
> - such a Makefile will change, but as noted in the above commits (and
> - GNU make's own documentation) any such change would be for the better,
> - so it's safe to do this.
> + I.e. this changes the behavior of existing rules in the altered
> + Makefiles (except "Makefile" & "Documentation/Makefile"). I'm
> + confident that this is safe having read the relevant rules in those
> + Makfiles, and as the GNU make manual notes that it isn't the default
> + behavior is out of an abundance of backwards compatibility
> + caution. From edition 0.75 of its manual, covering GNU make 4.3:
>
> - This also doesn't introduce a bug by e.g. having this
> + [Enabling '.DELETE_ON_ERROR' is] almost always what you want
> + 'make' to do, but it is not historical practice; so for
> + compatibility, you must explicitly request it.
> +
> + This doesn't introduce a bug by e.g. having this
> ".DELETE_ON_ERROR" flag only apply to this new shared.mak, Makefiles
> have no such scoping semantics.
I think this is much clearer now,
Best Wishes
Phillip
> + It does increase the danger that any Makefile without an explicit "The
> + default target of this Makefile is..." snippet to define the default
> + target as "all" could have its default rule changed if our new
> + shared.mak ever defines a "real" rule. In subsequent commits we'll be
> + careful not to do that, and such breakage would be obvious e.g. in the
> + case of "make -C t".
> +
> + We might want to make that less fragile still (e.g. by using
> + ".DEFAULT_GOAL" as noted in the preceding commit), but for now let's
> + simply include "shared.mak" without adding that boilerplate to all the
> + Makefiles that don't have it already. Most of those are already
> + exposed to that potential caveat e.g. due to including "config.mak*".
> +
> Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
>
> ## Documentation/Makefile ##
> @@ Documentation/Makefile: doc-l10n install-l10n::
>
> ## Makefile ##
> @@
> -+# Import tree-wide shared Makefile behavior and libraries
> -+include shared.mak
> -+
> # The default target of this Makefile is...
> all::
>
> ++# Import tree-wide shared Makefile behavior and libraries
> ++include shared.mak
> ++
> + # Define V=1 to have a more verbose compile.
> + #
> + # Define SHELL_PATH to a POSIX shell if your /bin/sh is broken.
> @@ Makefile: shell_compatibility_test: please_set_SHELL_PATH_to_a_more_modern_shell
> strip: $(PROGRAMS) git$X
> $(STRIP) $(STRIP_OPTS) $^
> @@ Makefile: shell_compatibility_test: please_set_SHELL_PATH_to_a_more_modern_shell
>
> ## contrib/scalar/Makefile ##
> @@
> + # The default target of this Makefile is...
> + all::
> +
> +# Import tree-wide shared Makefile behavior and libraries
> +include ../../shared.mak
> +
> - QUIET_SUBDIR0 = +$(MAKE) -C # space to separate -C and subdir
> - QUIET_SUBDIR1 =
> -
> + include ../../config.mak.uname
> + -include ../../config.mak.autogen
> + -include ../../config.mak
>
> ## contrib/scalar/t/Makefile ##
> @@
> 3: 9392e3c3e97 ! 3: 0fbdeeffc7b Makefile: disable GNU make built-in wildcard rules
> @@ Commit message
> contents from RCS or SCCS. See [1] for an old mailing list discussion
> about how to disable these.
>
> - The speed-up may wary. I've seen 1-10% depending on the speed of the
> + The speed-up may vary. I've seen 1-10% depending on the speed of the
> local disk, caches, -jN etc. Running:
>
> strace -f -c -S calls make -j1 NO_TCLTK=Y
> 4: 07cf9daa9d6 = 4: ea6b835308a Makefile: define $(LIB_H) in terms of $(FIND_SOURCE_FILES)
> 5: 16f2e3ff35b = 5: c2339694cf7 Makefile: move ".SUFFIXES" rule to shared.mak
> 6: 1b6ecb27f02 ! 6: 741fdfd48e2 Makefile: move $(comma), $(empty) and $(space) to shared.mak
> @@ Metadata
> ## Commit message ##
> Makefile: move $(comma), $(empty) and $(space) to shared.mak
>
> - Move these variables over to the shared.max, we'll make use of them in
> - a subsequent commit. There was no reason for these to be "simply
> - expanded variables", so let's use the normal lazy "=" assignment here.
> + Move these variables over to the shared.mak, we'll make use of them in
> + a subsequent commit.
> +
> + Note that there's reason for these to be "simply expanded variables",
> + i.e. to use ":=" assignments instead of lazily expanded "="
> + assignments. We could use "=", but let's leave this as-is for now for
> + ease of review.
>
> See 425ca6710b2 (Makefile: allow combining UBSan with other
> sanitizers, 2017-07-15) for the commit that introduced these.
> @@ shared.mak
> +
> +## comma, empty, space: handy variables as these tokens are either
> +## special or can be hard to spot among other Makefile syntax.
> -+comma = ,
> -+empty =
> -+space = $(empty) $(empty)
> ++comma := ,
> ++empty :=
> ++space := $(empty) $(empty)
> 7: 471067deefc ! 7: a723cbce270 Makefile: add "$(QUIET)" boilerplate to shared.mak
> @@ config.mak.uname: vcxproj:
>
>
> ## contrib/scalar/Makefile ##
> -@@
> - # Import tree-wide shared Makefile behavior and libraries
> - include ../../shared.mak
> +@@ contrib/scalar/Makefile: include ../../config.mak.uname
> + -include ../../config.mak.autogen
> + -include ../../config.mak
>
> -QUIET_SUBDIR0 = +$(MAKE) -C # space to separate -C and subdir
> -QUIET_SUBDIR1 =
> @@ contrib/scalar/Makefile
> -endif
> -endif
> -
> - include ../../config.mak.uname
> - -include ../../config.mak.autogen
> - -include ../../config.mak
> + TARGETS = scalar$(X) scalar.o
> + GITLIBS = ../../common-main.o ../../libgit.a ../../xdiff/lib.a
> +
>
> ## shared.mak ##
> @@
> - comma = ,
> - empty =
> - space = $(empty) $(empty)
> + comma := ,
> + empty :=
> + space := $(empty) $(empty)
> +
> +### Quieting
> +## common
> 8: 510306d2219 ! 8: 3733b0c8df1 Makefile: use $(wspfx) for $(QUIET...) in shared.mak
> @@ Commit message
> Makefile: use $(wspfx) for $(QUIET...) in shared.mak
>
> Change the mostly move-only change in the preceding commit to use the
> - $(wspfx) variable for defining the QUIET padding, to guarantee that
> - it's consistent with the "TRACK_template" template.
> + $(wspfx) variable for defining the QUIET padding. This refactoring
> + will make it easier to emit that exact amount of padding in functions
> + that we might add to shared.mak in the future.
>
> - $ make CFLAGS=-I$RANDOM grep.o wspfx='$(space)->'
> - -> GIT-CFLAGS PARAMETERS (changed)
> - -> CC grep.o
> + Such a function is not part of this patch series, but a
> + "TRACK_template" that I'd like to add as a follow-up to it makes use
> + of this. Let's make this change now while modifying these QUIET rules
> + is fresh in our minds.
>
> Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
>
> ## shared.mak ##
> -@@ shared.mak: comma = ,
> - empty =
> - space = $(empty) $(empty)
> +@@ shared.mak: comma := ,
> + empty :=
> + space := $(empty) $(empty)
>
> +## wspfx: the whitespace prefix padding for $(QUIET...) and similarly
> +## aligned output.
> 9: 85bb74aa32f = 9: 4cc4aeabb20 Makefiles: add and use wildcard "mkdir -p" template
next prev parent reply other threads:[~2022-03-03 14:08 UTC|newest]
Thread overview: 67+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-12-24 17:37 [PATCH v2 0/8] Makefile: optimize noop runs, add shared.mak Ævar Arnfjörð Bjarmason
2021-12-24 17:37 ` [PATCH v2 1/8] Makefiles: add "shared.mak", move ".DELETE_ON_ERROR" to it Ævar Arnfjörð Bjarmason
2021-12-24 17:37 ` [PATCH v2 2/8] Makefile: disable GNU make built-in wildcard rules Ævar Arnfjörð Bjarmason
2021-12-24 17:37 ` [PATCH v2 3/8] Makefile: define $(LIB_H) in terms of $(FIND_SOURCE_FILES) Ævar Arnfjörð Bjarmason
2021-12-24 17:37 ` [PATCH v2 4/8] Makefile: move ".SUFFIXES" rule to shared.mak Ævar Arnfjörð Bjarmason
2022-02-22 0:22 ` Taylor Blau
2022-02-22 11:14 ` Ævar Arnfjörð Bjarmason
2021-12-24 17:37 ` [PATCH v2 5/8] Makefile: move $(comma), $(empty) and $(space) " Ævar Arnfjörð Bjarmason
2021-12-24 17:37 ` [PATCH v2 6/8] Makefile: add "$(QUIET)" boilerplate " Ævar Arnfjörð Bjarmason
2021-12-24 17:37 ` [PATCH v2 7/8] Makefile: use $(wspfx) for $(QUIET...) in shared.mak Ævar Arnfjörð Bjarmason
2021-12-24 17:37 ` [PATCH v2 8/8] Makefiles: add and use wildcard "mkdir -p" template Ævar Arnfjörð Bjarmason
2022-02-21 20:17 ` [PATCH v2 0/8] Makefile: optimize noop runs, add shared.mak Ævar Arnfjörð Bjarmason
2022-02-25 9:04 ` [PATCH v3 0/9] " Ævar Arnfjörð Bjarmason
2022-02-25 9:04 ` [PATCH v3 1/9] scalar Makefile: set the default target after the includes Ævar Arnfjörð Bjarmason
2022-02-25 22:43 ` Junio C Hamano
2022-02-25 9:04 ` [PATCH v3 2/9] Makefiles: add "shared.mak", move ".DELETE_ON_ERROR" to it Ævar Arnfjörð Bjarmason
2022-02-25 22:47 ` Junio C Hamano
2022-02-25 23:05 ` Ævar Arnfjörð Bjarmason
2022-02-25 23:42 ` Junio C Hamano
2022-02-28 10:56 ` Phillip Wood
2022-02-28 11:16 ` Ævar Arnfjörð Bjarmason
2022-02-28 15:51 ` Phillip Wood
2022-02-28 16:34 ` Ævar Arnfjörð Bjarmason
2022-02-25 9:04 ` [PATCH v3 3/9] Makefile: disable GNU make built-in wildcard rules Ævar Arnfjörð Bjarmason
2022-02-25 23:17 ` Junio C Hamano
2022-02-25 9:04 ` [PATCH v3 4/9] Makefile: define $(LIB_H) in terms of $(FIND_SOURCE_FILES) Ævar Arnfjörð Bjarmason
2022-02-25 9:04 ` [PATCH v3 5/9] Makefile: move ".SUFFIXES" rule to shared.mak Ævar Arnfjörð Bjarmason
2022-02-25 23:19 ` Junio C Hamano
2022-02-25 9:04 ` [PATCH v3 6/9] Makefile: move $(comma), $(empty) and $(space) " Ævar Arnfjörð Bjarmason
2022-02-25 23:24 ` Junio C Hamano
2022-02-25 9:04 ` [PATCH v3 7/9] Makefile: add "$(QUIET)" boilerplate " Ævar Arnfjörð Bjarmason
2022-02-25 23:27 ` Junio C Hamano
2022-02-25 9:04 ` [PATCH v3 8/9] Makefile: use $(wspfx) for $(QUIET...) in shared.mak Ævar Arnfjörð Bjarmason
2022-02-25 23:30 ` Junio C Hamano
2022-02-25 9:04 ` [PATCH v3 9/9] Makefiles: add and use wildcard "mkdir -p" template Ævar Arnfjörð Bjarmason
2022-03-02 12:49 ` [PATCH v4 0/9] Makefile: optimize noop runs, add shared.mak Ævar Arnfjörð Bjarmason
2022-03-02 12:49 ` [PATCH v4 1/9] scalar Makefile: use "The default target of..." pattern Ævar Arnfjörð Bjarmason
2022-03-02 19:35 ` Junio C Hamano
2022-03-02 12:49 ` [PATCH v4 2/9] Makefiles: add "shared.mak", move ".DELETE_ON_ERROR" to it Ævar Arnfjörð Bjarmason
2022-03-02 12:49 ` [PATCH v4 3/9] Makefile: disable GNU make built-in wildcard rules Ævar Arnfjörð Bjarmason
2022-03-02 12:49 ` [PATCH v4 4/9] Makefile: define $(LIB_H) in terms of $(FIND_SOURCE_FILES) Ævar Arnfjörð Bjarmason
2022-03-02 12:49 ` [PATCH v4 5/9] Makefile: move ".SUFFIXES" rule to shared.mak Ævar Arnfjörð Bjarmason
2022-03-02 12:49 ` [PATCH v4 6/9] Makefile: move $(comma), $(empty) and $(space) " Ævar Arnfjörð Bjarmason
2022-03-02 12:49 ` [PATCH v4 7/9] Makefile: add "$(QUIET)" boilerplate " Ævar Arnfjörð Bjarmason
2022-03-02 12:49 ` [PATCH v4 8/9] Makefile: use $(wspfx) for $(QUIET...) in shared.mak Ævar Arnfjörð Bjarmason
2022-03-02 19:26 ` Junio C Hamano
2022-03-02 12:49 ` [PATCH v4 9/9] Makefiles: add and use wildcard "mkdir -p" template Ævar Arnfjörð Bjarmason
2022-03-02 20:38 ` Junio C Hamano
2022-03-02 20:39 ` [PATCH v4 0/9] Makefile: optimize noop runs, add shared.mak Junio C Hamano
2022-03-03 14:08 ` Phillip Wood [this message]
2022-03-03 16:04 ` [PATCH v5 0/8] " Ævar Arnfjörð Bjarmason
2022-03-03 16:04 ` [PATCH v5 1/8] scalar Makefile: use "The default target of..." pattern Ævar Arnfjörð Bjarmason
2022-03-03 16:04 ` [PATCH v5 2/8] Makefiles: add "shared.mak", move ".DELETE_ON_ERROR" to it Ævar Arnfjörð Bjarmason
2022-03-03 16:04 ` [PATCH v5 3/8] Makefile: disable GNU make built-in wildcard rules Ævar Arnfjörð Bjarmason
2022-04-11 10:05 ` Rene Kita
2022-04-11 10:11 ` Ævar Arnfjörð Bjarmason
2022-03-03 16:04 ` [PATCH v5 4/8] Makefile: define $(LIB_H) in terms of $(FIND_SOURCE_FILES) Ævar Arnfjörð Bjarmason
2022-03-03 16:04 ` [PATCH v5 5/8] Makefile: move ".SUFFIXES" rule to shared.mak Ævar Arnfjörð Bjarmason
2022-04-05 14:15 ` Adam Dinwoodie
2022-04-05 16:04 ` Ævar Arnfjörð Bjarmason
2022-04-05 19:56 ` [PATCH] Documentation/Makefile: fix "make info" regression in dad9cd7d518 Ævar Arnfjörð Bjarmason
2022-04-06 8:26 ` Adam Dinwoodie
2022-04-06 16:43 ` Junio C Hamano
2022-04-06 17:05 ` Taylor Blau
2022-03-03 16:04 ` [PATCH v5 6/8] Makefile: move $(comma), $(empty) and $(space) to shared.mak Ævar Arnfjörð Bjarmason
2022-03-03 16:04 ` [PATCH v5 7/8] Makefile: add "$(QUIET)" boilerplate " Ævar Arnfjörð Bjarmason
2022-03-03 16:04 ` [PATCH v5 8/8] Makefiles: add and use wildcard "mkdir -p" template Ævar Arnfjörð Bjarmason
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