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    SubjectRe: [BUG] TASK_DEAD task is able to be woken up in special condition
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    On Wed, 2011-12-28 at 16:07 -0500, KOSAKI Motohiro wrote:
    > I looked at scheduler code today briefly. now I'm afraid following code
    > have similar race.
    >
    >
    > if (task_contributes_to_load(p))
    > rq->nr_uninterruptible--;
    >
    >
    >
    > Can't following schenario be happen?
    >
    >
    > CPU0 CPU1
    > --------------------------------------------------------
    > deactivate_task()
    > task->state = TASK_UNINTERRUPTIBLE;
    > activate_task()
    > rq->nr_uninterruptible--;
    >
    > schedule()
    > deactivate_task()
    > rq->nr_uninterruptible++;
    >
    > Totally, nr_uninterruptible wasn't incremented.
    >
    >
    > I'm still not sure. I need to read more sched code.

    You shouldn't ever set another tasks ->state.



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