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

Phil Auld
2024-11-21T11:56:41Z

On Wed, Nov 20, 2024 at 07:37:39PM +0100 Mike Galbraith wrote:
> 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.
>

Thanks, I'll try that.

Cheers,
Phil

> -Mike
>

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