Messages in this thread | | | Date | Fri, 29 May 2015 16:34:20 +0200 | From | Peter Zijlstra <> | Subject | Re: [PATCH v2 7/7] sched/rt: reschedule if stop/dl task slip in after pull operations |
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On Wed, May 13, 2015 at 02:01:07PM +0800, Wanpeng Li wrote: > pull_rt_task() can drop (and re-acquire) rq->lock, this means a dl > or stop task can slip in, in which case need to reschedule. This > patch add the reschedule when the scenario occurs. > > Signed-off-by: Wanpeng Li <wanpeng.li@linux.intel.com> > --- > kernel/sched/rt.c | 19 ++++++++++++++++++- > 1 file changed, 18 insertions(+), 1 deletion(-) > > diff --git a/kernel/sched/rt.c b/kernel/sched/rt.c > index 560d2fa..8c948bf 100644 > --- a/kernel/sched/rt.c > +++ b/kernel/sched/rt.c > @@ -2136,7 +2136,14 @@ static void switched_from_rt(struct rq *rq, struct task_struct *p) > if (!task_on_rq_queued(p) || rq->rt.rt_nr_running) > return; > > - if (pull_rt_task(rq)) > + /* > + * pull_rt_task() can drop (and re-acquire) rq->lock; this > + * means a dl or stop task can slip in, in which case we need > + * to reschedule. > + */ > + if (pull_rt_task(rq) || > + (unlikely((rq->stop && task_on_rq_queued(rq->stop)) || > + rq->dl.dl_nr_running))) > resched_curr(rq); > }
Same as before; why is the normal wakeup preemption check not working?
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