Re: [PATCH v3 00/20] kbuild: significantly speed up kernel builds

[Linus Torvalds]

On Thu, 17 Sept 2026 at 09:06, Lorenzo Stoakes (ARM) <ljs@xxxxxxxxxx> wrote:
>
>                 == defconfig FULL build ==
>
>                         before    after     delta
>                       ----------------------------------
> Threadripper, gcc        32.5s    26.3s     -6.1s (-19%)
> Threadripper, clang      34.5s    27.2s     -7.3s (-21%)
> EPYC, gcc                28.7s    20.6s     -8.1s (-28%)
> EPYC, clang              39.8s    32.2s     -7.6s (-19%)
> M2, gcc                 519.3s   512.4s     -6.9s (-1%)
> M2, clang               634.5s   569.4s    -65.1s (-10%)

There's something odd going on with that M2 gcc build. Why is it such
an odd duck?

             Linus