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From: Mike Galbraith <efault@gmx.de>
To: Ingo Molnar <mingo@kernel.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>,
	Michael Wang <wangyun@linux.vnet.ibm.com>,
	LKML <linux-kernel@vger.kernel.org>, Paul Turner <pjt@google.com>,
	Andrew Morton <akpm@linux-foundation.org>,
	alex.shi@intel.com, Ram Pai <linuxram@us.ibm.com>,
	"Nikunj A. Dadhania" <nikunj@linux.vnet.ibm.com>,
	Namhyung Kim <namhyung@kernel.org>
Subject: Re: [RFC PATCH v3 0/3] sched: simplify the select_task_rq_fair()
Date: Fri, 22 Feb 2013 15:42:22 +0100	[thread overview]
Message-ID: <1361544142.1340.47.camel@marge.simpson.net> (raw)
In-Reply-To: <1361543459.1340.43.camel@marge.simpson.net>

On Fri, 2013-02-22 at 15:30 +0100, Mike Galbraith wrote: 
> On Fri, 2013-02-22 at 14:06 +0100, Ingo Molnar wrote: 

> > I think it might be better to measure the scheduling rate all 
> > the time, and save the _shortest_ cross-cpu-wakeup and 
> > same-cpu-wakeup latencies (since bootup) as a reference number. 
> > 
> > We might be able to pull this off pretty cheaply as the 
> > scheduler clock is running all the time and we have all the 
> > timestamps needed.
> 
> Yeah, that might work.  We have some quick kthreads, so saving ctx
> distance may get close enough to scheduler cost to be good enough.

Or better, shortest idle to idle, that would include the current (bad)
nohz cost, and automatically shrink away when that cost shrinks.

-Mike


      reply	other threads:[~2013-02-22 14:42 UTC|newest]

Thread overview: 55+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2013-01-29  9:08 Michael Wang
2013-01-29  9:09 ` [RFC PATCH v3 1/3] sched: schedule balance map foundation Michael Wang
2013-02-20 13:21   ` Peter Zijlstra
2013-02-21  4:52     ` Michael Wang
2013-02-20 13:25   ` Peter Zijlstra
2013-02-21  4:58     ` Michael Wang
2013-02-21 11:37       ` Peter Zijlstra
2013-02-22  2:53         ` Michael Wang
2013-02-22  3:33           ` Alex Shi
2013-02-22  4:19             ` Michael Wang
2013-02-22  4:46               ` Alex Shi
2013-02-22  5:05                 ` Michael Wang
2013-01-29  9:09 ` [RFC PATCH v3 2/3] sched: build schedule balance map Michael Wang
2013-01-29  9:10 ` [RFC PATCH v3 3/3] sched: simplify select_task_rq_fair() with " Michael Wang
2013-02-18  5:52 ` [RFC PATCH v3 0/3] sched: simplify the select_task_rq_fair() Michael Wang
2013-02-20 10:49 ` Ingo Molnar
2013-02-20 13:32   ` Peter Zijlstra
2013-02-20 14:05     ` Mike Galbraith
2013-02-21  5:21       ` Michael Wang
2013-02-21  5:14     ` Michael Wang
2013-02-21  4:51   ` Michael Wang
2013-02-21  6:11     ` Mike Galbraith
2013-02-21  7:00       ` Michael Wang
2013-02-21  8:10         ` Mike Galbraith
2013-02-21  9:08           ` Michael Wang
2013-02-21  9:43             ` Mike Galbraith
2013-02-22  2:36               ` Michael Wang
2013-02-22  5:02                 ` Mike Galbraith
2013-02-22  5:26                   ` Michael Wang
2013-02-22  6:13                     ` Mike Galbraith
2013-02-22  6:42                   ` Michael Wang
2013-02-22  8:17                     ` Mike Galbraith
2013-02-22  8:35                       ` Michael Wang
2013-02-22  8:21                 ` Peter Zijlstra
2013-02-22  9:10                   ` Michael Wang
2013-02-22  9:39                     ` Peter Zijlstra
2013-02-22  9:58                       ` Michael Wang
2013-02-21  9:20           ` Michael Wang
2013-02-21 10:20     ` Peter Zijlstra
2013-02-22  2:37       ` Michael Wang
2013-02-22  5:08         ` Mike Galbraith
2013-02-22  6:06           ` Michael Wang
2013-02-22  6:19             ` Mike Galbraith
2013-02-22  8:36         ` Peter Zijlstra
2013-02-22  9:11           ` Michael Wang
2013-02-22  9:57             ` Peter Zijlstra
2013-02-22 10:08               ` Michael Wang
2013-02-22  9:40           ` Mike Galbraith
2013-02-22  9:54             ` Ingo Molnar
2013-02-22 10:01               ` Mike Galbraith
2013-02-22 12:11                 ` Ingo Molnar
2013-02-22 12:35                   ` Mike Galbraith
2013-02-22 13:06                     ` Ingo Molnar
2013-02-22 14:30                       ` Mike Galbraith
2013-02-22 14:42                         ` Mike Galbraith [this message]

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