Re: [PATCH v2 4/4] sched/fair: Abort wakeup when task is no longer in a sleeping state

From	Peter Zijlstra <peterz@infradead.org>
Newsgroups	linux.kernel
Subject	Re: [PATCH v2 4/4] sched/fair: Abort wakeup when task is no longer in a sleeping state
Date	2016-02-13 13:20 +0100
Message-ID	<r1Hl7-4EJ-1@gated-at.bofh.it> (permalink)
References	<r1pRg-1EI-13@gated-at.bofh.it> <r1pRg-1EI-15@gated-at.bofh.it> <r1sm5-3kI-7@gated-at.bofh.it> <r1tBx-44h-15@gated-at.bofh.it>
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On Fri, Feb 12, 2016 at 04:22:29PM -0500, Waiman Long wrote:

> >>+	smp_cond_acquire(!p->on_cpu || !(p->state&  state));
> >>+	if (!(p->state&  state)) {
> >>+		success = 0;
> >>+		goto out;
> >>+	}
> >This doesn't make sense, if we managed to get here, p->on_rq must be
> >false, which means the other side is already in the middle of
> >schedule().
> Yes, you are right. It is my bad that I miss the on_rq check earlier. Just
> scrap the last patch.

No worries, that is tricky code :-)

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[PATCH v2 4/4] sched/fair: Abort wakeup when task is no longer in a sleeping state Waiman Long <Waiman.Long@hpe.com> - 2016-02-12 18:40 +0100
  Re: [PATCH v2 4/4] sched/fair: Abort wakeup when task is no longer  in a sleeping state Peter Zijlstra <peterz@infradead.org> - 2016-02-12 21:20 +0100
    Re: [PATCH v2 4/4] sched/fair: Abort wakeup when task is no longer  in a sleeping state Waiman Long <waiman.long@hpe.com> - 2016-02-12 22:40 +0100
      Re: [PATCH v2 4/4] sched/fair: Abort wakeup when task is no longer  in a sleeping state Peter Zijlstra <peterz@infradead.org> - 2016-02-13 13:20 +0100

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