From 0b6d0bc9246b006ed3c241d4faace132998162d9 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?=C3=86var=20Arnfj=C3=B6r=C3=B0=20Bjarmason?= Date: Thu, 3 Mar 2022 17:04:19 +0100 Subject: Makefiles: add and use wildcard "mkdir -p" template MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Add a template to do the "mkdir -p" of $(@D) (the parent dir of $@) for us, and use it for the "make lint-docs" targets I added in 8650c6298c1 (doc lint: make "lint-docs" non-.PHONY, 2021-10-15). As seen in 4c64fb5aad9 (Documentation/Makefile: fix lint-docs mkdir dependency, 2021-10-26) maintaining these manual lists of parent directory dependencies is fragile, in addition to being obviously verbose. I used this pattern at the time because I couldn't find another method than "order-only" prerequisites to avoid doing a "mkdir -p $(@D)" for every file being created, which as noted in [1] would be significantly slower. But as it turns out we can use this neat trick of only doing a "mkdir -p" if the $(wildcard) macro tells us the path doesn't exist. A re-run of a performance test similar to that noted downthread of [1] in [2] shows that this is faster, in addition to being less verbose and more reliable (this uses my "git-hyperfine" thin wrapper for "hyperfine"[3]): $ git -c hyperfine.hook.setup= hyperfine -L rev HEAD~1,HEAD~0 -s 'make -C Documentation lint-docs' -p 'rm -rf Documentation/.build' 'make -C Documentation -j1 lint-docs' Benchmark 1: make -C Documentation -j1 lint-docs' in 'HEAD~1 Time (mean ± σ): 2.914 s ± 0.062 s [User: 2.449 s, System: 0.489 s] Range (min … max): 2.834 s … 3.020 s 10 runs Benchmark 2: make -C Documentation -j1 lint-docs' in 'HEAD~0 Time (mean ± σ): 2.315 s ± 0.062 s [User: 1.950 s, System: 0.386 s] Range (min … max): 2.229 s … 2.397 s 10 runs Summary 'make -C Documentation -j1 lint-docs' in 'HEAD~0' ran 1.26 ± 0.04 times faster than 'make -C Documentation -j1 lint-docs' in 'HEAD~1' So let's use that pattern both for the "lint-docs" target, and a few miscellaneous other targets. This method of creating parent directories is explicitly racy in that we don't know if we're going to say always create a "foo" followed by a "foo/bar" under parallelism, or skip the "foo" because we created "foo/bar" first. In this case it doesn't matter for anything except that we aren't guaranteed to get the same number of rules firing when running make in parallel. 1. https://lore.kernel.org/git/211028.861r45y3pt.gmgdl@evledraar.gmail.com/ 2. https://lore.kernel.org/git/211028.86o879vvtp.gmgdl@evledraar.gmail.com/ 3. https://gitlab.com/avar/git-hyperfine/ Signed-off-by: Ævar Arnfjörð Bjarmason Signed-off-by: Junio C Hamano --- Documentation/Makefile | 25 +++---------------------- 1 file changed, 3 insertions(+), 22 deletions(-) (limited to 'Documentation/Makefile') diff --git a/Documentation/Makefile b/Documentation/Makefile index 0f4ebdeda8..1eb9192dae 100644 --- a/Documentation/Makefile +++ b/Documentation/Makefile @@ -434,25 +434,11 @@ quick-install-html: require-htmlrepo print-man1: @for i in $(MAN1_TXT); do echo $$i; done -## Lint: Common -.build: - $(QUIET)mkdir $@ -.build/lint-docs: | .build - $(QUIET)mkdir $@ - ## Lint: gitlink -.build/lint-docs/gitlink: | .build/lint-docs - $(QUIET)mkdir $@ -.build/lint-docs/gitlink/howto: | .build/lint-docs/gitlink - $(QUIET)mkdir $@ -.build/lint-docs/gitlink/config: | .build/lint-docs/gitlink - $(QUIET)mkdir $@ LINT_DOCS_GITLINK = $(patsubst %.txt,.build/lint-docs/gitlink/%.ok,$(HOWTO_TXT) $(DOC_DEP_TXT)) -$(LINT_DOCS_GITLINK): | .build/lint-docs/gitlink -$(LINT_DOCS_GITLINK): | .build/lint-docs/gitlink/howto -$(LINT_DOCS_GITLINK): | .build/lint-docs/gitlink/config $(LINT_DOCS_GITLINK): lint-gitlink.perl $(LINT_DOCS_GITLINK): .build/lint-docs/gitlink/%.ok: %.txt + $(call mkdir_p_parent_template) $(QUIET_LINT_GITLINK)$(PERL_PATH) lint-gitlink.perl \ $< \ $(HOWTO_TXT) $(DOC_DEP_TXT) \ @@ -463,23 +449,18 @@ $(LINT_DOCS_GITLINK): .build/lint-docs/gitlink/%.ok: %.txt lint-docs-gitlink: $(LINT_DOCS_GITLINK) ## Lint: man-end-blurb -.build/lint-docs/man-end-blurb: | .build/lint-docs - $(QUIET)mkdir $@ LINT_DOCS_MAN_END_BLURB = $(patsubst %.txt,.build/lint-docs/man-end-blurb/%.ok,$(MAN_TXT)) -$(LINT_DOCS_MAN_END_BLURB): | .build/lint-docs/man-end-blurb $(LINT_DOCS_MAN_END_BLURB): lint-man-end-blurb.perl $(LINT_DOCS_MAN_END_BLURB): .build/lint-docs/man-end-blurb/%.ok: %.txt + $(call mkdir_p_parent_template) $(QUIET_LINT_MANEND)$(PERL_PATH) lint-man-end-blurb.perl $< >$@ .PHONY: lint-docs-man-end-blurb -lint-docs-man-end-blurb: $(LINT_DOCS_MAN_END_BLURB) ## Lint: man-section-order -.build/lint-docs/man-section-order: | .build/lint-docs - $(QUIET)mkdir $@ LINT_DOCS_MAN_SECTION_ORDER = $(patsubst %.txt,.build/lint-docs/man-section-order/%.ok,$(MAN_TXT)) -$(LINT_DOCS_MAN_SECTION_ORDER): | .build/lint-docs/man-section-order $(LINT_DOCS_MAN_SECTION_ORDER): lint-man-section-order.perl $(LINT_DOCS_MAN_SECTION_ORDER): .build/lint-docs/man-section-order/%.ok: %.txt + $(call mkdir_p_parent_template) $(QUIET_LINT_MANSEC)$(PERL_PATH) lint-man-section-order.perl $< >$@ .PHONY: lint-docs-man-section-order lint-docs-man-section-order: $(LINT_DOCS_MAN_SECTION_ORDER) -- cgit v1.2.3