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From: Yong Zhang <yong.zhang0@gmail.com>
To: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>,
	Thomas Gleixner <tglx@linutronix.de>,
	LKML <linux-kernel@vger.kernel.org>,
	linux-rt-users <linux-rt-users@vger.kernel.org>,
	Ingo Molnar <mingo@elte.hu>, Carsten Emde <ce@ceag.ch>,
	Clark Williams <williams@redhat.com>,
	Kumar Gala <galak@gate.crashing.org>,
	Ralf Baechle <ralf@linux-mips.org>, rostedt <rostedt@goodmis.org>,
	Nicholas Mc Guire <der.herr@hofr.at>
Subject: Re: On migrate_disable() and latencies
Date: Thu, 28 Jul 2011 13:50:43 +0800	[thread overview]
Message-ID: <20110728055043.GA570@windriver.com> (raw)
In-Reply-To: <20110727183008.GA2407@linux.vnet.ibm.com>

On Wed, Jul 27, 2011 at 11:30:08AM -0700, Paul E. McKenney wrote:
> o	Tasks awakening outside of migrate-disable regions will pick
> 	the CPU running the lowest-priority task, whether or not this
> 	task is in migrate-disable state.  (At least I don't see
> 	anything in 3.0-rt3 that looks like a scheduling decision
> 	based on ->migrate_disable, perhaps due to blindness.)

I'm also confused here, seems we just disable migration for RT task.
migrate_disable()
{
	...
		if (p->sched_class->set_cpus_allowed)
			p->sched_class->set_cpus_allowed(p, mask);
		p->rt.nr_cpus_allowed =	cpumask_weight(mask);
	...
}

Shouldn't we also forbid migration on !RT task?

Thanks,
Yong

-- 
Only stand for myself

  reply	other threads:[~2011-07-28  5:59 UTC|newest]

Thread overview: 15+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2011-07-22 10:19 On migrate_disable() and latencies Peter Zijlstra
2011-07-22 10:49 ` Peter Zijlstra
2011-07-22 14:57   ` Peter Zijlstra
2011-07-22 17:45 ` Nicholas Mc Guire
2011-07-25  8:21   ` Peter Zijlstra
2011-07-23  0:39 ` Paul E. McKenney
2011-07-25  8:30   ` Peter Zijlstra
2011-07-25 21:17     ` Paul E. McKenney
2011-07-27 11:13       ` Peter Zijlstra
2011-07-27 18:30         ` Paul E. McKenney
2011-07-28  5:50           ` Yong Zhang [this message]
2011-07-28  7:01             ` Thomas Gleixner
2011-07-28  7:10               ` Yong Zhang
2011-07-28  7:54           ` Nicholas Mc Guire
2011-07-28 12:05             ` Paul E. McKenney

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