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| author | Masahiro Yamada <masahiroy@kernel.org> | 2022-09-25 03:19:13 +0900 |
|---|---|---|
| committer | Masahiro Yamada <masahiroy@kernel.org> | 2022-09-29 06:07:58 +0900 |
| commit | f73edc8951b2de515b5ecc8a357ccd47dd41077e (patch) | |
| tree | d47510e68b59ee420a244941b11be9a189c7e955 /scripts/Makefile.modfinal | |
| parent | 9c5a0ac3c36917c4258f734bda98be02ca36b992 (diff) | |
| download | lwn-f73edc8951b2de515b5ecc8a357ccd47dd41077e.tar.gz lwn-f73edc8951b2de515b5ecc8a357ccd47dd41077e.zip | |
kbuild: unify two modpost invocations
Currently, modpost is executed twice; first for vmlinux, second
for modules.
This commit merges them.
Current build flow
==================
1) build obj-y and obj-m objects
2) link vmlinux.o
3) modpost for vmlinux
4) link vmlinux
5) modpost for modules
6) link modules (*.ko)
The build steps 1) through 6) are serialized, that is, modules are
built after vmlinux. You do not get benefits of parallel builds when
scripts/link-vmlinux.sh is being run.
New build flow
==============
1) build obj-y and obj-m objects
2) link vmlinux.o
3) modpost for vmlinux and modules
4a) link vmlinux
4b) link modules (*.ko)
In the new build flow, modpost is invoked just once.
vmlinux and modules are built in parallel. One exception is
CONFIG_DEBUG_INFO_BTF_MODULES=y, where modules depend on vmlinux.
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Tested-by: Nick Desaulniers <ndesaulniers@google.com>
Reviewed-by: Nicolas Schier <nicolas@fjasle.eu>
Diffstat (limited to 'scripts/Makefile.modfinal')
| -rw-r--r-- | scripts/Makefile.modfinal | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/scripts/Makefile.modfinal b/scripts/Makefile.modfinal index 35100e981f4a..a3cf9e3647c9 100644 --- a/scripts/Makefile.modfinal +++ b/scripts/Makefile.modfinal @@ -55,7 +55,7 @@ if_changed_except = $(if $(call newer_prereqs_except,$(2))$(cmd-check), \ printf '%s\n' 'cmd_$@ := $(make-cmd)' > $(dot-target).cmd, @:) # Re-generate module BTFs if either module's .ko or vmlinux changed -$(modules): %.ko: %.o %.mod.o scripts/module.lds $(if $(KBUILD_BUILTIN),vmlinux) FORCE +$(modules): %.ko: %.o %.mod.o scripts/module.lds $(and $(CONFIG_DEBUG_INFO_BTF_MODULES),$(KBUILD_BUILTIN),vmlinux) FORCE +$(call if_changed_except,ld_ko_o,vmlinux) ifdef CONFIG_DEBUG_INFO_BTF_MODULES +$(if $(newer-prereqs),$(call cmd,btf_ko)) |