Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752758Ab3DLDRj (ORCPT ); Thu, 11 Apr 2013 23:17:39 -0400 Received: from e28smtp05.in.ibm.com ([122.248.162.5]:60795 "EHLO e28smtp05.in.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751736Ab3DLDRi (ORCPT ); Thu, 11 Apr 2013 23:17:38 -0400 Message-ID: <51677CB0.606@linux.vnet.ibm.com> Date: Fri, 12 Apr 2013 11:17:04 +0800 From: Michael Wang User-Agent: Mozilla/5.0 (X11; Linux i686; rv:16.0) Gecko/20121011 Thunderbird/16.0.1 MIME-Version: 1.0 To: Peter Zijlstra , Peter Zijlstra CC: LKML , Ingo Molnar , Mike Galbraith , Alex Shi , Namhyung Kim , Paul Turner , Andrew Morton , "Nikunj A. Dadhania" , Ram Pai Subject: Re: [PATCH] sched: wake-affine throttle References: <5164DCE7.8080906@linux.vnet.ibm.com> <1365583873.30071.31.camel@laptop> In-Reply-To: <1365583873.30071.31.camel@laptop> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit X-TM-AS-MML: No X-Content-Scanned: Fidelis XPS MAILER x-cbid: 13041203-8256-0000-0000-0000070A6F73 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1294 Lines: 40 On 04/10/2013 04:51 PM, Peter Zijlstra wrote: > On Wed, 2013-04-10 at 11:30 +0800, Michael Wang wrote: >> | 15 GB | 32 | 35918 | | 37632 | +4.77% | 47923 | +33.42% | >> 52241 | +45.45% > > So I don't get this... is wake_affine() once every milisecond _that_ > expensive? > > Seeing we get a 45%!! improvement out of once every 100ms that would > mean we're like spending 1/3rd of our time in wake_affine()? that's > preposterous. So what's happening? Hi, Peter I think Mike has very well explained the reason why throttle bring us benefit and why the benefit looks so significant when interval get higher, could you please take a look at his mail and see whether it addressed this concern? And thanks Mike again for the excellent analysis :) Regards, Michael Wang > > > > -- > 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/