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    SubjectRe: [PATCH 04/21] sched: Change the ttwu success details
    On Wed, 2011-04-13 at 11:23 +0200, Peter Zijlstra wrote:
    > and workqueue wakeups, and I doubt extra wakeups will cause lockups.

    Damn assumptions ;-)

    Index: linux-2.6/kernel/sched.c
    --- linux-2.6.orig/kernel/sched.c
    +++ linux-2.6/kernel/sched.c
    @@ -2447,7 +2447,7 @@ static inline void ttwu_post_activation(
    /* if a worker is waking up, notify workqueue */
    - if ((p->flags & PF_WQ_WORKER) && success)
    + if (p->flags & PF_WQ_WORKER)
    wq_worker_waking_up(p, cpu_of(rq));

    Appears to be sufficient to cause the lockup, so somehow the whole
    workqueue stuff relies on the fact that waking a TASK_(UN)INTERRUPTIBLE
    task that hasn't been dequeued yet isn't a wakeup.

    Tejun any quick clues as to why and how to cure this?

    /me goes read that stuff

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      Last update: 2011-04-13 12:49    [W:0.021 / U:6.920 seconds]
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