[PATCH] compiler: allow all arches to enable CONFIG_OPTIMIZE_INLINING
mingo at kernel.org
Thu Apr 18 06:20:47 PDT 2019
* Masahiro Yamada <yamada.masahiro at socionext.com> wrote:
> Commit 60a3cdd06394 ("x86: add optimized inlining") introduced
> CONFIG_OPTIMIZE_INLINING, but it has been available only for x86.
> The idea is obviously arch-agnostic although we need some code fixups.
> This commit moves the config entry from arch/x86/Kconfig.debug to
> lib/Kconfig.debug so that all architectures (except MIPS for now) can
> benefit from it.
> At this moment, I added "depends on !MIPS" because fixing 0day bot reports
> for MIPS was complex to me.
> I tested this patch on my arm/arm64 boards.
> This can make a huge difference in kernel image size especially when
> CONFIG_OPTIMIZE_FOR_SIZE is enabled.
> For example, I got 3.5% smaller arm64 kernel image for v5.1-rc1.
> dec file
> 18983424 arch/arm64/boot/Image.before
> 18321920 arch/arm64/boot/Image.after
> This also slightly improves the "Kernel hacking" Kconfig menu.
> Commit e61aca5158a8 ("Merge branch 'kconfig-diet' from Dave Hansen')
> mentioned this config option would be a good fit in the "compiler option"
> menu. I did so.
No objections against moving it from x86 code to generic code.
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