Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1759548Ab0KQAXT (ORCPT ); Tue, 16 Nov 2010 19:23:19 -0500 Received: from mga09.intel.com ([134.134.136.24]:4092 "EHLO mga09.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755498Ab0KQAXR (ORCPT ); Tue, 16 Nov 2010 19:23:17 -0500 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="4.59,208,1288594800"; d="scan'208";a="678212730" Subject: Re: [performance bug] volanomark regression on 37-rc1 From: "Alex,Shi" To: Rakib Mullick Cc: "ncrao@google.com" , "a.p.zijlstra@chello.nl" , "mingo@elte.hu" , "linux-kernel@vger.kernel.org" , "Chen, Tim C" , "Yan, Zheng Z" In-Reply-To: References: <1289900042.27424.253.camel@debian> Content-Type: text/plain; charset="UTF-8" Date: Wed, 17 Nov 2010 08:23:57 +0800 Message-ID: <1289953437.27424.271.camel@debian> Mime-Version: 1.0 X-Mailer: Evolution 2.28.1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2279 Lines: 58 On Tue, 2010-11-16 at 22:38 +0800, Rakib Mullick wrote: > On 11/16/10, Alex,Shi wrote: > > When do performance testing on 37-rc1 kernel on Core2 machines, we find > > the volanomark loopback performance drop about 30%, that due to > > commit:fab476228ba37907ad7 > > > Was that test was made before and after applying above commit? Would > love to know, how did you find that commit (I mean was it a git > bisection)? Yes, git bisect found this commit. > > > > It seems some of load_balance() is not necessary that caused by avg_idle > > setting. But do not know more details of the volano running. Anyone like > > to give a comments for this issue? > > > Does VolanoMark is used for scheduler benchmarking? If I'm not wrong, > I don't think it directly relates to scheduler benchmarking. Yes, but lots of benchmarks often find other part kernel issues. like hackbench/netperf often find VM performance issues. And an our cache testing tool often find scheduler problem. > > > Ncrao, I have no idea of your benchmarks, but just guess removing the > > avg_idle setting won't bring much wakeup delay for tasks. Could you like > > to show some data of this? > > > > The vmstat output for .36 and .37-rc1 kernel as below: > > You are showing the output of .36 and .37-rc1. If Ncrao's commit is > guilty for this performance regression, then what are the results of > before and after applied Ncrao's commit. Then, what are the result > after applying your patch. You are showing vmstat output of .36 and > .37-rc1, which really doesn't prove the point of your patch. It needs > to be more clearer. The vmstat for .36 represents original kernel, .37-rc1 represent with the Ncrao's patch. > > > thanks, > rakib > > > > Regards > > Alex > > > > -- > > To unsubscribe from this list: send the line "unsubscribe linux-kernel" in > > the body of a message to majordomo@vger.kernel.org > > More majordomo info at http://vger.kernel.org/majordomo-info.html > > Please read the FAQ at http://www.tux.org/lkml/ > > -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/