[RFC PATCH v1 1/3] Revert "powerpc/bug: Provide better flexibility to WARN_ON/__WARN_FLAGS() with asm goto"
Naveen N Rao
naveen at kernel.org
Tue Jun 20 15:21:25 AEST 2023
Christophe Leroy wrote:
> This reverts commit 1e688dd2a3d6759d416616ff07afc4bb836c4213.
>
> That commit aimed at optimising the code around generation of
> WARN_ON/BUG_ON but this leads to a lot of dead code erroneously
> generated by GCC.
>
> text data bss dec hex filename
> 9551585 3627834 224376 13403795 cc8693 vmlinux.before
> 9535281 3628358 224376 13388015 cc48ef vmlinux.after
>
> Once this change is reverted, in a standard configuration (pmac32 +
> function tracer) the text is reduced by 16k which is around 1.7%
Aneesh recently reported a build failure due to the use of 'asm goto' in
WARN_ON(). We were able to root-cause it to the use of 'asm goto' with
two config options: CONFIG_CC_OPTIMIZE_FOR_SIZE and
CONFIG_DEBUG_SECTION_MISMATCH.
Along with the issues we found with 'asm goto' during objtool
enablement, I think it might be better to disable it for now.
Acked-by: Naveen N Rao <naveen at kernel.org>
- Naveen
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