Re: [GIT PULL] Scheduler changes for v6.8

[Linus Torvalds]

On Wed, 10 Jan 2024 at 14:41, Linus Torvalds
<torvalds@xxxxxxxxxxxxxxxxxxxx> wrote:
>
> It's one of these two:
>
>   f12560779f9d sched/cpufreq: Rework iowait boost
>   9c0b4bb7f630 sched/cpufreq: Rework schedutil governor performance estimation
>
> one more boot to go, then I'll try to revert whichever causes my
> machine to perform horribly much worse.

I guess it should come as no surprise that the result is

   9c0b4bb7f6303c9c4e2e34984c46f5a86478f84d is the first bad commit

but to revert cleanly I will have to revert all of

      b3edde44e5d4 ("cpufreq/schedutil: Use a fixed reference frequency")
      f12560779f9d ("sched/cpufreq: Rework iowait boost")
      9c0b4bb7f630 ("sched/cpufreq: Rework schedutil governor
performance estimation")

This is on a 32-core (64-thread) AMD Ryzen Threadripper 3970X, fwiw.

I'll keep that revert in my private test-tree for now (so that I have
a working machine again), but I'll move it to my main branch soon
unless somebody has a quick fix for this problem.

                Linus