From d21832e212d2613c0a0f3e5f09967cb3402c8a53 Mon Sep 17 00:00:00 2001 From: Arnd Bergmann Date: Thu, 1 Jun 2017 16:57:07 +0200 Subject: kbuild: speed up checksyscalls.sh checksyscalls.sh is run at every "make" run while building the kernel, even if no files have changed. I looked at where we spend time in a trivial empty rebuild and found checksyscalls.sh to be a source of noticeable overhead, as it spawns a lot of child processes just to call 'cat' copying from stdin to stdout, once for each of the over 400 x86 syscalls. Using a shell-builtin (echo) instead of the external command gives us a 13x speedup: Before After real 0m1.018s real 0m0.077s user 0m0.068s user 0m0.048s sys 0m0.156s sys 0m0.024s The time it took to rebuild a single file on my machine dropped from 5.5 seconds to 4.5 seconds. Signed-off-by: Arnd Bergmann Signed-off-by: Masahiro Yamada --- scripts/checksyscalls.sh | 11 ++++------- 1 file changed, 4 insertions(+), 7 deletions(-) (limited to 'scripts') diff --git a/scripts/checksyscalls.sh b/scripts/checksyscalls.sh index 116b7735ee9f..5a387a264201 100755 --- a/scripts/checksyscalls.sh +++ b/scripts/checksyscalls.sh @@ -202,15 +202,12 @@ EOF } syscall_list() { - grep '^[0-9]' "$1" | sort -n | ( + grep '^[0-9]' "$1" | sort -n | while read nr abi name entry ; do - cat < Date: Fri, 9 Jun 2017 17:29:52 +0900 Subject: kbuild: replace genhdr-y with generated-y Originally, generated-y and genhdr-y had different meaning, like follows: - generated-y: generated headers (other than asm-generic wrappers) - header-y : headers to be exported - genhdr-y : generated headers to be exported (generated-y + header-y) Since commit fcc8487d477a ("uapi: export all headers under uapi directories"), headers under UAPI directories are all exported. So, there is no more difference between generated-y and genhdr-y. We see two users of genhdr-y, arch/{arm,x86}/include/uapi/asm/Kbuild. They generate some headers in arch/{arm,x86}/include/generated/uapi/asm directories, which are obviously exported. Replace them with generated-y, and abolish genhdr-y. Signed-off-by: Masahiro Yamada Acked-by: Nicolas Dichtel --- scripts/Makefile.asm-generic | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'scripts') diff --git a/scripts/Makefile.asm-generic b/scripts/Makefile.asm-generic index e4d017d53819..95f7d8090152 100644 --- a/scripts/Makefile.asm-generic +++ b/scripts/Makefile.asm-generic @@ -15,7 +15,7 @@ _dummy := $(shell [ -d $(obj) ] || mkdir -p $(obj)) # Stale wrappers when the corresponding files are removed from generic-y # need removing. -generated-y := $(generic-y) $(genhdr-y) $(generated-y) +generated-y := $(generic-y) $(generated-y) all-files := $(patsubst %, $(obj)/%, $(generated-y)) old-headers := $(wildcard $(obj)/*.h) unwanted := $(filter-out $(all-files),$(old-headers)) -- cgit v1.2.3 From 39a33ff80a259b2bddebb236549baee55f9b4f41 Mon Sep 17 00:00:00 2001 From: Masahiro Yamada Date: Mon, 19 Jun 2017 16:28:22 +0900 Subject: kbuild: remove cc-option-align Documentation/kbuild/makefiles.txt says the change for align options occurred at GCC 3.0, and Documentation/process/changes.rst says the minimal supported GCC version is 3.2, so it should be safe to hard-code -falign* options. Fix the only user arch/x86/Makefile_32.cpu and remove cc-option-align. Signed-off-by: Masahiro Yamada Acked-by: Ingo Molnar --- scripts/Kbuild.include | 5 ----- 1 file changed, 5 deletions(-) (limited to 'scripts') diff --git a/scripts/Kbuild.include b/scripts/Kbuild.include index 61f87a99bf0a..53b7d47ce43a 100644 --- a/scripts/Kbuild.include +++ b/scripts/Kbuild.include @@ -123,11 +123,6 @@ cc-option = $(call try-run,\ cc-option-yn = $(call try-run,\ $(CC) -Werror $(KBUILD_CPPFLAGS) $(CC_OPTION_CFLAGS) $(1) -c -x c /dev/null -o "$$TMP",y,n) -# cc-option-align -# Prefix align with either -falign or -malign -cc-option-align = $(subst -functions=0,,\ - $(call cc-option,-falign-functions=0,-malign-functions=0)) - # cc-disable-warning # Usage: cflags-y += $(call cc-disable-warning,unused-but-set-variable) cc-disable-warning = $(call try-run,\ -- cgit v1.2.3 From 9f3f1fd299768782465cb32cdf0dd4528d11f26b Mon Sep 17 00:00:00 2001 From: Matthias Kaehlcke Date: Wed, 21 Jun 2017 16:28:03 -0700 Subject: kbuild: Add __cc-option macro cc-option uses KBUILD_CFLAGS and KBUILD_CPPFLAGS when it determines whether an option is supported or not. This is fine for options used to build the kernel itself, however some components like the x86 boot code use a different set of flags. Add the new macro __cc-option which is a more generic version of cc-option with additional parameters. One parameter is the compiler with which the check should be performed, the other the compiler options to be used instead KBUILD_C*FLAGS. Refactor cc-option and hostcc-option to use __cc-option and move hostcc-option to scripts/Kbuild.include. Suggested-by: Arnd Bergmann Suggested-by: Masahiro Yamada Signed-off-by: Matthias Kaehlcke Acked-by: Arnd Bergmann Acked-by: Michal Marek Signed-off-by: Masahiro Yamada --- scripts/Kbuild.include | 14 ++++++++++++-- scripts/Makefile.host | 6 ------ 2 files changed, 12 insertions(+), 8 deletions(-) (limited to 'scripts') diff --git a/scripts/Kbuild.include b/scripts/Kbuild.include index 53b7d47ce43a..dd8e2dde0b34 100644 --- a/scripts/Kbuild.include +++ b/scripts/Kbuild.include @@ -108,6 +108,11 @@ as-option = $(call try-run,\ as-instr = $(call try-run,\ printf "%b\n" "$(1)" | $(CC) $(KBUILD_AFLAGS) -c -x assembler -o "$$TMP" -,$(2),$(3)) +# __cc-option +# Usage: MY_CFLAGS += $(call __cc-option,$(CC),$(MY_CFLAGS),-march=winchip-c6,-march=i586) +__cc-option = $(call try-run,\ + $(1) -Werror $(2) $(3) -c -x c /dev/null -o "$$TMP",$(3),$(4)) + # Do not attempt to build with gcc plugins during cc-option tests. # (And this uses delayed resolution so the flags will be up to date.) CC_OPTION_CFLAGS = $(filter-out $(GCC_PLUGINS_CFLAGS),$(KBUILD_CFLAGS)) @@ -115,8 +120,13 @@ CC_OPTION_CFLAGS = $(filter-out $(GCC_PLUGINS_CFLAGS),$(KBUILD_CFLAGS)) # cc-option # Usage: cflags-y += $(call cc-option,-march=winchip-c6,-march=i586) -cc-option = $(call try-run,\ - $(CC) -Werror $(KBUILD_CPPFLAGS) $(CC_OPTION_CFLAGS) $(1) -c -x c /dev/null -o "$$TMP",$(1),$(2)) +cc-option = $(call __cc-option, $(CC),\ + $(KBUILD_CPPFLAGS) $(CC_OPTION_CFLAGS),$(1),$(2)) + +# hostcc-option +# Usage: cflags-y += $(call hostcc-option,-march=winchip-c6,-march=i586) +hostcc-option = $(call __cc-option, $(HOSTCC),\ + $(HOSTCFLAGS) $(HOST_EXTRACFLAGS),$(1),$(2)) # cc-option-yn # Usage: flag := $(call cc-option-yn,-march=winchip-c6) diff --git a/scripts/Makefile.host b/scripts/Makefile.host index 45b5b1aaedbd..9cfd5c84d76f 100644 --- a/scripts/Makefile.host +++ b/scripts/Makefile.host @@ -20,12 +20,6 @@ # Will compile qconf as a C++ program, and menu as a C program. # They are linked as C++ code to the executable qconf -# hostcc-option -# Usage: cflags-y += $(call hostcc-option,-march=winchip-c6,-march=i586) - -hostcc-option = $(call try-run,\ - $(HOSTCC) $(HOSTCFLAGS) $(HOST_EXTRACFLAGS) $(1) -c -x c /dev/null -o "$$TMP",$(1),$(2)) - __hostprogs := $(sort $(hostprogs-y) $(hostprogs-m)) host-cshlib := $(sort $(hostlibs-y) $(hostlibs-m)) host-cxxshlib := $(sort $(hostcxxlibs-y) $(hostcxxlibs-m)) -- cgit v1.2.3