Re: [PATCH] sched/fair: Dequeue sched_delayed tasks when waking to a busy CPU

Mike Galbraith
2024-11-20T18:38:28Z

On Tue, 2024-11-19 at 12:51 +0100, Mike Galbraith wrote:
> On Tue, 2024-11-19 at 06:30 -0500, Phil Auld wrote:
> >
> > This, below, by itself, did not do help and caused a small slowdown on some
> > other tests.  Did this need to be on top of the wakeup change?
>
> No, that made a mess.

Rashly speculating that turning mobile kthread component loose is what
helped your write regression...

You could try adding (p->flags & PF_KTHREAD) to the wakeup patch to
only turn hard working kthreads loose to try to dodge service latency.
Seems unlikely wakeup frequency * instances would combine to shred fio
the way turning tbench loose did.

-Mike