From dad9cd7d518375799413b5a3af179f4cd95cfbe4 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?=C3=86var=20Arnfj=C3=B6r=C3=B0=20Bjarmason?= Date: Thu, 3 Mar 2022 17:04:16 +0100 Subject: Makefile: move ".SUFFIXES" rule to shared.mak MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit This was added in 30248886ce8 (Makefile: disable default implicit rules, 2010-01-26), let's move it to the top of "shared.mak" so it'll apply to all our Makefiles. This doesn't benefit the main Makefile at all, since it already had the rule, but since we're including shared.mak in other Makefiles starts to benefit them. E.g. running the 'man" target is now faster: $ git -c hyperfine.hook.setup= hyperfine -L rev HEAD~1,HEAD~0 -s 'make -C Documentation man' 'make -C Documentation -j1 man' Benchmark 1: make -C Documentation -j1 man' in 'HEAD~1 Time (mean ± σ): 121.7 ms ± 8.8 ms [User: 105.8 ms, System: 18.6 ms] Range (min … max): 112.8 ms … 148.4 ms 26 runs Benchmark 2: make -C Documentation -j1 man' in 'HEAD~0 Time (mean ± σ): 97.5 ms ± 8.0 ms [User: 80.1 ms, System: 20.1 ms] Range (min … max): 89.8 ms … 111.8 ms 32 runs Summary 'make -C Documentation -j1 man' in 'HEAD~0' ran 1.25 ± 0.14 times faster than 'make -C Documentation -j1 man' in 'HEAD~1' The reason for that can be seen when comparing that run with "--debug=a". Without this change making a target like "git-status.1" will cause "make" to consider not only "git-status.txt", but "git-status.txt.o", as well as numerous other implicit suffixes such as ".c", ".cc", ".cpp" etc. See [1] for a more detailed before/after example. So this is causing us to omit a bunch of work we didn't need to do. For making "git-status.1" the "--debug=a" output is reduced from ~140k lines to ~6k. 1. https://lore.kernel.org/git/220222.86bkyz875k.gmgdl@evledraar.gmail.com/ Signed-off-by: Ævar Arnfjörð Bjarmason Signed-off-by: Junio C Hamano --- shared.mak | 5 +++++ 1 file changed, 5 insertions(+) (limited to 'shared.mak') diff --git a/shared.mak b/shared.mak index 29f0e69ecb..1dda948df0 100644 --- a/shared.mak +++ b/shared.mak @@ -9,6 +9,11 @@ %:: s.% %:: SCCS/s.% +## Likewise delete default $(SUFFIXES). See: +## +## info make --index-search=.SUFFIXES +.SUFFIXES: + ### Flags affecting all rules # A GNU make extension since gmake 3.72 (released in late 1994) to -- cgit v1.2.3