Messages in this thread | | | Date | Thu, 6 Mar 2008 16:45:25 +0530 | From | Gautham R Shenoy <> | Subject | Re: [BUG 2.6.25-rc3] scheduler/hotplug: some processes are dealocked when cpu is set to offline |
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On Wed, Mar 05, 2008 at 04:53:14PM +0300, Oleg Nesterov wrote: > On 03/05, Gautham R Shenoy wrote: > > > > On Tue, Mar 04, 2008 at 06:01:07PM +0300, Oleg Nesterov wrote: > > > On 03/04, Gautham R Shenoy wrote: > > > > > > > > So at times, the callback thread is blocked on kthread_stop(k) in > > > > softlockup.c, while other time, it was blocked in > > > > cleanup_workqueue_threads() in workqueue.c. > > > > > > >From another message: > > > > > > > > However, it remains in R< state > > > > > > What about cwq->thread? Was it TASK_RUNNING too? > > > > No, it was in TASK_UNINTERRUPTIBLE state. The last thing it ever > > executed was the wait_for_completion in flush_cpu_workqueue() > > You misunderstood ;) The task doing _cpu_down() hang in flush_cpu_workqueue(), > because cwq->thread doesn't want to die. But what was cwq->thread->state? >
Yup, sorry for that stupid reply.
> Could you try the patch? Yi constantly sees the tasks in R< state. > I am starting to suspect some scheduling issue.
Me too. With your patch applied there were quite a few tasks in the running state which didn't get the cpu for more than 120 seconds.
I could be a scheduler problem which CPU-Hotplug is able to catch more easily. Will try a git bisect.
> > Oleg.
-- Thanks and Regards gautham
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