Messages in this thread | | | Date | Tue, 07 Apr 2015 18:32:47 +0300 | From | Konstantin Khlebnikov <> | Subject | Re: [PATCH RFC] sched/fair: fix sudden expiration of cfq quota in put_prev_task() |
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On 07.04.2015 18:12, Peter Zijlstra wrote: > On Tue, Apr 07, 2015 at 03:47:58PM +0200, Peter Zijlstra wrote: >> Lemme think a bit more on that. > > So going by 734ff2a71f9e ("sched/rt: Fix picking RT and DL tasks from > empty queue") something like this would be called for. > > --- > kernel/sched/fair.c | 15 +++++++++++++++ > 1 file changed, 15 insertions(+) > > diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c > index fdae26eb7218..1e47f816c976 100644 > --- a/kernel/sched/fair.c > +++ b/kernel/sched/fair.c > @@ -5175,6 +5175,21 @@ pick_next_task_fair(struct rq *rq, struct task_struct *prev) > return p; > simple: > cfs_rq = &rq->cfs;
We don't need this if prev isn't from fair_sched_class: first "goto simple" should go directly to "if (!cfs_rq->nr_running)".
> + > + if (cfs_bandwidth_used()) { > + /* > + * We may dequeue prev's cfs_rq in put_prev_task(). > + * So, we update time before cfs_rq->nr_running check. > + */ > + if (prev->on_rq) > + update_curr(cfs_rq); > + > + se = &prev->se; > + for_each_sched_entity(se) {
Probably update_curr() should be inside loop too?
> + cfs_rq = cfs_rq_of(se); > + check_cfs_rq_runtime(cfs_rq); > + } > + } > #endif > > if (!cfs_rq->nr_running) >
-- Konstantin
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