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From: Mike Galbraith <mgalbraith@suse.de>
To: Matt Fleming <matt@codeblueprint.co.uk>, Chris Mason <clm@fb.com>,
	Peter Zijlstra <peterz@infradead.org>,
	Ingo Molnar <mingo@kernel.org>,
	linux-kernel@vger.kernel.org
Subject: Re: [PATCH RFC] select_idle_sibling experiments
Date: Wed, 13 Apr 2016 05:40:20 +0200	[thread overview]
Message-ID: <1460518820.3780.37.camel@suse.de> (raw)
In-Reply-To: <20160412214502.GI2829@codeblueprint.co.uk>

On Tue, 2016-04-12 at 22:45 +0100, Matt Fleming wrote:
> On Sat, 09 Apr, at 01:30:34PM, Chris Mason wrote:
> > 
> > [ nohz throttling patch ]
> > 
> > I tested the nohz throttle two different ways, first with schbench's
> > pipe simulation, it's easily 8% faster with messages bouncing between
> > cpus.
> > 
> > In production it's hard to pick a single number because the benchmarks
> > produce latency curves as the workload scales up in RPS.  The benefits
> > range from 2-9% depending on the metric.  It's a nice win, and I'd love to
> > see it go in.
> 
> Do we have any idea what the tradeoff is against power consumption for
> throttling nohz?

That's measurable with the built in super duper watt meter gizmo
(turbostat).  It should be dinky but existent, could be given an off
button for particularly attentive laptop drivers to poke.  Servers
drivers are unlikely to care given the performance win.

	-Mike

  reply	other threads:[~2016-04-13  3:40 UTC|newest]

Thread overview: 80+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2016-04-05 18:08 [PATCH RFC] select_idle_sibling experiments Chris Mason
2016-04-05 18:43 ` Bastien Bastien Philbert
2016-04-05 19:28   ` Chris Mason
2016-04-05 20:03 ` Matt Fleming
2016-04-05 21:05   ` Bastien Philbert
2016-04-06  0:44   ` Chris Mason
2016-04-06  7:27 ` Mike Galbraith
2016-04-06 13:36   ` Chris Mason
2016-04-09 17:30   ` Chris Mason
2016-04-12 21:45     ` Matt Fleming
2016-04-13  3:40       ` Mike Galbraith [this message]
2016-04-13 15:54         ` Chris Mason
2016-04-28 12:00   ` Peter Zijlstra
2016-04-28 13:17     ` Mike Galbraith
2016-05-02  5:35     ` Mike Galbraith
2016-04-07 15:17 ` Chris Mason
2016-04-09 19:05 ` sched: tweak select_idle_sibling to look for idle threads Chris Mason
2016-04-10 10:04   ` Mike Galbraith
2016-04-10 12:35     ` Chris Mason
2016-04-10 12:46       ` Mike Galbraith
2016-04-10 19:55     ` Chris Mason
2016-04-11  4:54       ` Mike Galbraith
2016-04-12  0:30         ` Chris Mason
2016-04-12  4:44           ` Mike Galbraith
2016-04-12 13:27             ` Chris Mason
2016-04-12 18:16               ` Mike Galbraith
2016-04-12 20:07                 ` Chris Mason
2016-04-13  3:18                   ` Mike Galbraith
2016-04-13 13:44                     ` Chris Mason
2016-04-13 14:22                       ` Mike Galbraith
2016-04-13 14:36                         ` Chris Mason
2016-04-13 15:05                           ` Mike Galbraith
2016-04-13 15:34                             ` Mike Galbraith
2016-04-30 12:47   ` Peter Zijlstra
2016-05-01  7:12     ` Mike Galbraith
2016-05-01  8:53       ` Peter Zijlstra
2016-05-01  9:20         ` Mike Galbraith
2016-05-07  1:24           ` Yuyang Du
2016-05-08  8:08             ` Mike Galbraith
2016-05-08 18:57               ` Yuyang Du
2016-05-09  3:45                 ` Mike Galbraith
2016-05-08 20:22                   ` Yuyang Du
2016-05-09  7:44                     ` Mike Galbraith
2016-05-09  1:13                       ` Yuyang Du
2016-05-09  9:39                         ` Mike Galbraith
2016-05-09 23:26                           ` Yuyang Du
2016-05-10  7:49                             ` Mike Galbraith
2016-05-10 15:26                               ` Mike Galbraith
2016-05-10 19:16                                 ` Yuyang Du
2016-05-11  4:17                                   ` Mike Galbraith
2016-05-11  1:23                                     ` Yuyang Du
2016-05-11  9:56                                       ` Mike Galbraith
2016-05-18  6:41                                   ` Mike Galbraith
2016-05-09  3:52                 ` Mike Galbraith
2016-05-08 20:31                   ` Yuyang Du
2016-05-02  8:46       ` Peter Zijlstra
2016-05-02 14:50         ` Mike Galbraith
2016-05-02 14:58           ` Peter Zijlstra
2016-05-02 15:47             ` Chris Mason
2016-05-03 14:32               ` Peter Zijlstra
2016-05-03 15:11                 ` Chris Mason
2016-05-04 10:37                   ` Peter Zijlstra
2016-05-04 15:31                     ` Peter Zijlstra
2016-05-05 22:03                     ` Matt Fleming
2016-05-06 18:54                       ` Mike Galbraith
2016-05-09  8:33                         ` Peter Zijlstra
2016-05-09  8:56                           ` Mike Galbraith
2016-05-04 15:45                   ` Peter Zijlstra
2016-05-04 17:46                     ` Chris Mason
2016-05-05  9:33                       ` Peter Zijlstra
2016-05-05 13:58                         ` Chris Mason
2016-05-06  7:12                           ` Peter Zijlstra
2016-05-06 17:27                             ` Chris Mason
2016-05-06  7:25                   ` Peter Zijlstra
2016-05-02 17:30             ` Mike Galbraith
2016-05-02 15:01           ` Peter Zijlstra
2016-05-02 16:04             ` Ingo Molnar
2016-05-03 11:31               ` Peter Zijlstra
2016-05-03 18:22                 ` Peter Zijlstra
2016-05-02 15:10           ` Peter Zijlstra

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