Commit 88694cff authored Feb 28, 2020 by Quentin Perret Committed by Masahiro Yamada Mar 03, 2020

kbuild: generate autoksyms.h early



When doing a cold build, autoksyms.h starts empty, and is updated late
in the build process to have visibility over the symbols used by in-tree
drivers. But since the symbol whitelist is known upfront, it can be used
to pre-populate autoksyms.h and maximize the amount of code that can be
compiled to its final state in a single pass, hence reducing build time.

Do this by using gen_autoksyms.sh to initialize autoksyms.h instead of
creating an empty file.

Acked-by: Nicolas Pitre <nico@fluxnic.net>
Tested-by: Matthias Maennich <maennich@google.com>
Reviewed-by: Matthias Maennich <maennich@google.com>
Signed-off-by: Quentin Perret <qperret@google.com>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>

parent cd195bc4

Makefile

+5 −2

Original line number	Diff line number	Diff line
		@@ -1066,9 +1066,12 @@ endif

		autoksyms_h := $(if $(CONFIG_TRIM_UNUSED_KSYMS), include/generated/autoksyms.h)

		quiet_cmd_autoksyms_h = GEN $@
		cmd_autoksyms_h = mkdir -p $(dir $@); \
		$(CONFIG_SHELL) $(srctree)/scripts/gen_autoksyms.sh $@

		$(autoksyms_h):
		$(Q)mkdir -p $(dir $@)
		$(Q)touch $@
		$(call cmd,autoksyms_h)

		ARCH_POSTLINK := $(wildcard $(srctree)/arch/$(SRCARCH)/Makefile.postlink)

scripts/gen_autoksyms.sh

+2 −1

Original line number	Diff line number	Diff line
		@@ -39,7 +39,8 @@ cat > "$output_file" << EOT

		EOT

		sed 's/ko$/mod/' modules.order \|
		[ -f modules.order ] && modlist=modules.order \|\| modlist=/dev/null
		sed 's/ko$/mod/' $modlist \|
		xargs -n1 sed -n -e '2{s/ /\n/g;/^$/!p;}' -- \|
		cat - "$ksym_wl" \|
		sort -u \|

Original line number	Diff line number	Diff line
		@@ -39,7 +39,8 @@ cat > "$output_file" << EOT

		EOT

		sed 's/ko$/mod/' modules.order \|
		[ -f modules.order ] && modlist=modules.order \|\| modlist=/dev/null
		sed 's/ko$/mod/' $modlist \|
		xargs -n1 sed -n -e '2{s/ /\n/g;/^$/!p;}' -- \|
		cat - "$ksym_wl" \|
		sort -u \|

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