Re: [PATCH] modpost: Optimize symbol search from linear to binary search

From: Masahiro Yamada
Date: Tue Oct 03 2023 - 07:36:12 EST


On Tue, Sep 26, 2023 at 9:40 PM Jack Brennen <jbrennen@xxxxxxxxxx> wrote:
>
> Modify modpost to use binary search for converting addresses back
> into symbol references. Previously it used linear search.
>
> This change saves a few seconds of wall time for defconfig builds,
> but can save several minutes on allyesconfigs.
>
> Before:
> $ make LLVM=1 -j128 allyesconfig vmlinux -s KCFLAGS="-Wno-error"
> $ time scripts/mod/modpost -M -m -a -N -o vmlinux.symvers vmlinux.o
> 198.38user 1.27system 3:19.71elapsed
>
> After:
> $ make LLVM=1 -j128 allyesconfig vmlinux -s KCFLAGS="-Wno-error"
> $ time scripts/mod/modpost -M -m -a -N -o vmlinux.symvers vmlinux.o
> 11.91user 0.85system 0:12.78elapsed
>
> Signed-off-by: Jack Brennen <jbrennen@xxxxxxxxxx>
> Tested-by: Nick Desaulniers <ndesaulniers@xxxxxxxxxx>



Applied to linux-kbuild.
Thanks.



--
Best Regards
Masahiro Yamada