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

[Peter Zijlstra]

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 :-)