Re: [PATCH] sched: fix rt_nr_migratory corruption raised inpush_rt_task()

From: Steven Rostedt
Date: Tue May 31 2011 - 11:08:07 EST


On Tue, 2011-05-31 at 21:56 +0800, Hillf Danton wrote:
> On Tue, May 31, 2011 at 3:36 PM, Mike Galbraith <efault@xxxxxx> wrote:
> > On Mon, 2011-05-30 at 21:39 +0800, Hillf Danton wrote:
> >> When pushing, if a pushable task could not be pushed, it is dequeued with no
> >> updating the rt_nr_migratory element of RT run-queue, then rt_nr_migratory is
> >> corrupted, which is fixed by removing the dequeue operation.
> >
> > Hm. I think you're right that this dequeue_pushable_task() call can be
> > removed, at least I didn't see it's reason for existing. I'd word it a
> > bit differently though, and not return 1 unless we really did push.
> >
>
> Hi Mike
>
> Your message shows what is called professional work, but something lost,
>
> > From: Hillf Danton <dhillf@xxxxxxxxx>
> >
> > sched, rt: fix rq->rt.pushable_tasks bug in push_rt_task()
> >
> > Do not call dequeue_pushable_task() when failing to push an eligible
> > task, as it remains pushable, merely not at this particular moment.
> >
> > Signed-off-by: Hillf Danton <dhillf@xxxxxxxxx>
>
> Signed-off-by: Mike Galbraith <efault@xxxxxx>
>

Yeah, Mike, can you remail this adding your SOB too. You can keep
Hillf's SOB as well, since both of you made changes.

Thanks!

-- Steve


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