Re: [PATCH v2 2/6] sched/cpuset: Bring back cpuset_mutex

From: Juri Lelli
Date: Thu May 04 2023 - 04:18:37 EST


On 04/05/23 08:21, Peter Zijlstra wrote:
> On Wed, May 03, 2023 at 09:22:24AM +0200, Juri Lelli wrote:
> > Turns out percpu_cpuset_rwsem - commit 1243dc518c9d ("cgroup/cpuset:
> > Convert cpuset_mutex to percpu_rwsem") - wasn't such a brilliant idea,
> > as it has been reported to cause slowdowns in workloads that need to
> > change cpuset configuration frequently and it is also not implementing
> > priority inheritance (which causes troubles with realtime workloads).
>
> What were they doing ? Dynamically adjusting the DL parameters?
>

Yes, calling sched_setattr to adjust params and/or add/remove DL
reservations.