https://gcc.gnu.org/g:b75d81d95f49d694ed2edbd383207c00c8b1da77
commit r17-2659-gb75d81d95f49d694ed2edbd383207c00c8b1da77 Author: Harmen Stoppels <[email protected]> Date: Thu Jul 23 11:57:42 2026 +0200 libsanitizer: parallelize subdir builds Automake normally builds subdirectories sequentially, which makes the libsanitizer builds effectively sequential as there is little parallelism per subdirectory. This patch replaces the all-recursive loop with an explicit dependency graph: asan and hwasan depend on lsan, while others just need sanitizer_common. Exposing this DAG to make raises the CPU load from 2.3 to 3.7, yielding a roughly 30% reduction in build time on multi-core machines. libsanitizer/ChangeLog: * Makefile.am: Override all-recursive and define explicit DAG dependencies for all-* targets to enable parallel builds. * Makefile.in: Regenerate. Signed-off-by: Harmen Stoppels <[email protected]> Reviewed-by: Jakub Jelinek <[email protected]> Diff: --- libsanitizer/Makefile.am | 24 ++++++++++++++++++++++++ libsanitizer/Makefile.in | 20 ++++++++++++++++++++ 2 files changed, 44 insertions(+) diff --git a/libsanitizer/Makefile.am b/libsanitizer/Makefile.am index 53e20bdac2c5..2e3245c8d871 100644 --- a/libsanitizer/Makefile.am +++ b/libsanitizer/Makefile.am @@ -26,6 +26,30 @@ endif if HWASAN_SUPPORTED SUBDIRS += hwasan endif + +# Override all-recursive and explicitly define the dependency graph +# to increase parallelism during the build. + +all-sanitizer_common all-interception all-libbacktrace: + +cd $(@:all-%=%) && $(MAKE) $(AM_MAKEFLAGS) all + +SANITIZER_BASE_DEPS = all-sanitizer_common +if !USING_MAC_INTERPOSE +SANITIZER_BASE_DEPS += all-interception +endif +if LIBBACKTRACE_SUPPORTED +SANITIZER_BASE_DEPS += all-libbacktrace +endif + +all-lsan all-ubsan all-tsan: $(SANITIZER_BASE_DEPS) + +cd $(@:all-%=%) && $(MAKE) $(AM_MAKEFLAGS) all + +all-asan all-hwasan: $(SANITIZER_BASE_DEPS) all-lsan + +cd $(@:all-%=%) && $(MAKE) $(AM_MAKEFLAGS) all + +all-recursive: $(SUBDIRS:%=all-%) + +.PHONY: $(SUBDIRS:%=all-%) endif ## Force DIST_SUBDIRS so that make distclean works diff --git a/libsanitizer/Makefile.in b/libsanitizer/Makefile.in index fa6fe9e26a3e..280e45cdbe49 100644 --- a/libsanitizer/Makefile.in +++ b/libsanitizer/Makefile.in @@ -98,6 +98,8 @@ target_triplet = @target@ @LIBBACKTRACE_SUPPORTED_TRUE@@SANITIZER_SUPPORTED_TRUE@am__append_3 = libbacktrace @SANITIZER_SUPPORTED_TRUE@@TSAN_SUPPORTED_TRUE@am__append_4 = tsan @HWASAN_SUPPORTED_TRUE@@SANITIZER_SUPPORTED_TRUE@am__append_5 = hwasan +@SANITIZER_SUPPORTED_TRUE@@USING_MAC_INTERPOSE_FALSE@am__append_6 = all-interception +@LIBBACKTRACE_SUPPORTED_TRUE@@SANITIZER_SUPPORTED_TRUE@am__append_7 = all-libbacktrace subdir = . ACLOCAL_M4 = $(top_srcdir)/aclocal.m4 am__aclocal_m4_deps = $(top_srcdir)/../config/acx.m4 \ @@ -370,6 +372,8 @@ nodist_saninclude_HEADERS = $(am__append_1) @SANITIZER_SUPPORTED_TRUE@SUBDIRS = sanitizer_common $(am__append_2) \ @SANITIZER_SUPPORTED_TRUE@ $(am__append_3) lsan asan ubsan \ @SANITIZER_SUPPORTED_TRUE@ $(am__append_4) $(am__append_5) +@SANITIZER_SUPPORTED_TRUE@SANITIZER_BASE_DEPS = all-sanitizer_common \ +@SANITIZER_SUPPORTED_TRUE@ $(am__append_6) $(am__append_7) DIST_SUBDIRS = $(SUBDIRS) gcc_version := $(shell @get_gcc_base_ver@ $(top_srcdir)/../gcc/BASE-VER) @@ -765,6 +769,22 @@ uninstall-am: uninstall-nodist_sanincludeHEADERS \ .PRECIOUS: Makefile +# Override all-recursive and explicitly define the dependency graph +# to increase parallelism during the build. + +@SANITIZER_SUPPORTED_TRUE@all-sanitizer_common all-interception all-libbacktrace: +@SANITIZER_SUPPORTED_TRUE@ +cd $(@:all-%=%) && $(MAKE) $(AM_MAKEFLAGS) all + +@SANITIZER_SUPPORTED_TRUE@all-lsan all-ubsan all-tsan: $(SANITIZER_BASE_DEPS) +@SANITIZER_SUPPORTED_TRUE@ +cd $(@:all-%=%) && $(MAKE) $(AM_MAKEFLAGS) all + +@SANITIZER_SUPPORTED_TRUE@all-asan all-hwasan: $(SANITIZER_BASE_DEPS) all-lsan +@SANITIZER_SUPPORTED_TRUE@ +cd $(@:all-%=%) && $(MAKE) $(AM_MAKEFLAGS) all + +@SANITIZER_SUPPORTED_TRUE@all-recursive: $(SUBDIRS:%=all-%) + +@[email protected]: $(SUBDIRS:%=all-%) + # GNU Make needs to see an explicit $(MAKE) variable in the command it # runs to enable its job server during parallel builds. Hence the # comments below.
