Messages in this thread | | | Subject | Re: [Question] sched: Should nr_uninterruptible be decremented in ttwu_do_activate()? | From | Peter Zijlstra <> | Date | Thu, 12 Jan 2012 21:25:45 +0100 |
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On Thu, 2012-01-12 at 23:08 +0600, Rakib Mullick wrote:
> That might be the case for scheduler_ipi(), but when > sched_ttwu_pending() gets called when a cpu goes down, all tasks from > wake_list of that cpu has been moved without TASK_WAKING is set. For a > particular task it might be possible that when it ran previously it > had p->sched_contributes_to_load is set. Latter, this task's cpu has > been put down and calls sched_ttwu_pending(), then for that task > p->sched_contributes_to_load is set and TASK_WAKING is not set. > Couldn't be happen?
No, look again, its impossible to be on that list and not be TASK_WAKING.
The only way onto the list is through ttwu_queue_remote(), the only way off the list is through sched_ttwu_pending().
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