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    SubjectRe: [PATCH 2/5] workqueue: change value of lcpu in queue_delayed_work_on()
    >> And, do u mean  @cpu is WORK_CPU_UNBOUND?
    > @cpu could be WORK_CPU_UNBOUND at that point. The timer will be added
    > to local CPU but @work->data would be pointing to WORK_CPU_UNBOUND,
    > again triggering the condition. Given that @cpu being
    > WORK_CPU_UNBOUND is far more common than an actual CPU number, the
    > patch would actually increase spurious nrt lookups. The right thing
    > to do is probably setting cpu to raw_smp_processor_id() beforehand.

    I got your point.
    Thanks for kind illustration.

    Following is a alternative implementation for this.
    I thinks this is too rare case, so it doesn't help in any real workload.
    But how do you thinks?

    @@ -1156,7 +1156,9 @@ int queue_delayed_work_on(int cpu, struct
    workqueue_struct *wq,
    if (!(wq->flags & WQ_UNBOUND)) {
    struct global_cwq *gcwq = get_work_gcwq(work);

    - if (gcwq && gcwq->cpu != WORK_CPU_UNBOUND)
    + if (!gcwq)
    + lcpu = cpu;
    + else if (gcwq->cpu != WORK_CPU_UNBOUND)
    lcpu = gcwq->cpu;
    lcpu = raw_smp_processor_id();

     \ /
      Last update: 2012-08-13 20:23    [W:0.022 / U:4.856 seconds]
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