From: Peter Zijlstra <a.p.zijlstra@chello.nl>
To: Rakib Mullick <rakib.mullick@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>, LKML <linux-kernel@vger.kernel.org>
Subject: Re: [Question] sched: Should nr_uninterruptible be decremented in ttwu_do_activate()?
Date: Thu, 12 Jan 2012 21:25:45 +0100 [thread overview]
Message-ID: <1326399945.2442.212.camel@twins> (raw)
In-Reply-To: <CADZ9YHiGjjGJjxKj4WKWydqAz0zxFwY5=LsYBKhEREuZm=bKpg@mail.gmail.com>
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().
next prev parent reply other threads:[~2012-01-12 20:26 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-01-11 17:22 [Question] sched: Should nr_uninterruptible be decremented in ttwu_do_activate()? Rakib Mullick
2012-01-11 17:29 ` Peter Zijlstra
2012-01-12 6:09 ` Rakib Mullick
2012-01-12 7:25 ` Peter Zijlstra
2012-01-12 17:08 ` Rakib Mullick
2012-01-12 20:25 ` Peter Zijlstra [this message]
2012-01-16 7:53 ` Michael Wang
2012-01-16 8:27 ` Rakib Mullick
2012-01-16 9:22 ` Michael Wang
2012-01-16 17:22 ` Rakib Mullick
2012-01-16 13:00 ` Hillf Danton
2012-01-16 17:26 ` Rakib Mullick
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