Re: [PATCH v6 6/7] AutoFDO: Enable machine function split optimization for AutoFDO

Kees Cook
2024-10-29T00:13:13Z

On Fri, Oct 25, 2024 at 10:14:08PM -0700, Rong Xu wrote:
> Enable the machine function split optimization for AutoFDO in Clang.
>
> Machine function split (MFS) is a pass in the Clang compiler that
> splits a function into hot and cold parts. The linker groups all
> cold blocks across functions together. This decreases hot code
> fragmentation and improves iCache and iTLB utilization.
>
> MFS requires a profile so this is enabled only for the AutoFDO builds.
>
> Co-developed-by: Han Shen <shenhan@google.com>
> Signed-off-by: Han Shen <shenhan@google.com>

Reviewed-by: Kees Cook <kees@kernel.org>

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Kees Cook