Messages in this thread | ![/](/images/icornerl.gif) | | Date | Fri, 26 Apr 2024 13:16:07 +0200 | From | Peter Zijlstra <> | Subject | Re: [RFC][PATCH 08/10] sched/fair: Implement delayed dequeue |
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On Fri, Apr 26, 2024 at 12:56:07PM +0200, Peter Zijlstra wrote: > On Thu, Apr 25, 2024 at 01:28:55PM +0200, Peter Zijlstra wrote: > > On Thu, Apr 18, 2024 at 06:24:59PM +0200, Mike Galbraith wrote: > > > The root cause seems to be doing the delay dequeue business on > > > exiting tasks. > > > > > --- > > > kernel/sched/fair.c | 5 +++-- > > > 1 file changed, 3 insertions(+), 2 deletions(-) > > > > > > --- a/kernel/sched/fair.c > > > +++ b/kernel/sched/fair.c > > > @@ -5374,6 +5374,7 @@ dequeue_entity(struct cfs_rq *cfs_rq, st > > > update_curr(cfs_rq); > > > > > > if (sched_feat(DELAY_DEQUEUE) && sleep && > > > + !(entity_is_task(se) && (task_of(se)->flags & PF_EXITING)) && > > > !entity_eligible(cfs_rq, se)) { > > > if (cfs_rq->next == se) > > > cfs_rq->next = NULL; > > > > So I think this can be easier done in dequeue_task_fair(), where we > > still know this is a task. > > > > Perhaps something like (I'll test later): > > > > if (p->flags & PF_EXITING) > > flags &= ~DEQUEUE_SLEEP; > > > > But now I need to go think about the case of removing a cgroup... > > *urgh*. > > I ended up with the below instead; lemme go run this unixbench spawn on it.
Seems to survive that.
I pushed out the patches with updates to queue/sched/eevdf
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