From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758284Ab3BOPFp (ORCPT ); Fri, 15 Feb 2013 10:05:45 -0500 Received: from hrndva-omtalb.mail.rr.com ([71.74.56.122]:11895 "EHLO hrndva-omtalb.mail.rr.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754726Ab3BOPFn (ORCPT ); Fri, 15 Feb 2013 10:05:43 -0500 X-Authority-Analysis: v=2.0 cv=It2cgcDg c=1 sm=0 a=rXTBtCOcEpjy1lPqhTCpEQ==:17 a=mNMOxpOpBa8A:10 a=MPEKn9ueenIA:10 a=5SG0PmZfjMsA:10 a=Q9fys5e9bTEA:10 a=meVymXHHAAAA:8 a=zGjexpQmzOwA:10 a=Jd30bWH-SSQKBtd5NLQA:9 a=PUjeQqilurYA:10 a=rXTBtCOcEpjy1lPqhTCpEQ==:117 X-Cloudmark-Score: 0 X-Authenticated-User: X-Originating-IP: 74.67.115.198 Message-ID: <1360940741.23152.110.camel@gandalf.local.home> Subject: Re: [RFC] sched: The removal of idle_balance() From: Steven Rostedt To: Joonsoo Kim Cc: LKML , Linus Torvalds , Ingo Molnar , Peter Zijlstra , Thomas Gleixner , Paul Turner , Frederic Weisbecker , Andrew Morton , Mike Galbraith , Arnaldo Carvalho de Melo , Clark Williams , Andrew Theurer Date: Fri, 15 Feb 2013 10:05:41 -0500 In-Reply-To: <20130215074538.GA25845@lge.com> References: <1360908819.23152.97.camel@gandalf.local.home> <20130215074538.GA25845@lge.com> Content-Type: text/plain; charset="ISO-8859-15" X-Mailer: Evolution 3.4.4-1 Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, 2013-02-15 at 16:45 +0900, Joonsoo Kim wrote: > Hello, Steven. > - Before Patch > Permance counter stats for 'perf bench sched messaging -g 300' (10 runs): > > 40847.488740 task-clock # 3.232 CPUs utilized ( +- 1.24% ) > 511,070 context-switches # 0.013 M/sec ( +- 7.28% ) > 117,882 cpu-migrations # 0.003 M/sec ( +- 5.14% ) > 1,360,501 page-faults # 0.033 M/sec ( +- 0.12% ) > 118,534,394,180 cycles # 2.902 GHz ( +- 1.23% ) [50.70%] > stalled-cycles-frontend > stalled-cycles-backend > 46,217,340,271 instructions # 0.39 insns per cycle ( +- 0.56% ) [76.93%] > 8,592,447,548 branches # 210.354 M/sec ( +- 0.75% ) [75.50%] > 273,367,481 branch-misses # 3.18% of all branches ( +- 0.26% ) [75.49%] > > 12.639049245 seconds time elapsed ( +- 2.29% ) > > - After Patch > Performance counter stats for 'perf bench sched messaging -g 300' (10 runs): > > 42053.008632 task-clock # 2.932 CPUs utilized ( +- 0.91% ) > 672,759 context-switches # 0.016 M/sec ( +- 2.76% ) > 83,374 cpu-migrations # 0.002 M/sec ( +- 4.46% ) > 1,362,900 page-faults # 0.032 M/sec ( +- 0.20% ) > 121,457,601,848 cycles # 2.888 GHz ( +- 0.93% ) [50.75%] > stalled-cycles-frontend > stalled-cycles-backend > 47,854,828,552 instructions # 0.39 insns per cycle ( +- 0.36% ) [77.09%] > 8,981,553,714 branches # 213.577 M/sec ( +- 0.42% ) [75.41%] > 274,229,438 branch-misses # 3.05% of all branches ( +- 0.20% ) [75.44%] > > 14.340330678 seconds time elapsed ( +- 1.79% ) > Interesting that perf bench gives me a little better performance with the idle_balance than without too. But hackbench still shows a huge performance without idle_balance. The funny part about that is perf bench sched messaging is based off of hackbench?? I would really like to know why hackbench gets a 50% performance without idle balancing. Perhaps it is some kind of fluke :-/ -- Steve