From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752776Ab3BVGGa (ORCPT ); Fri, 22 Feb 2013 01:06:30 -0500 Received: from e28smtp02.in.ibm.com ([122.248.162.2]:45222 "EHLO e28smtp02.in.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750814Ab3BVGG2 (ORCPT ); Fri, 22 Feb 2013 01:06:28 -0500 Message-ID: <51270AD9.9020908@linux.vnet.ibm.com> Date: Fri, 22 Feb 2013 14:06:17 +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: Mike Galbraith CC: Peter Zijlstra , Ingo Molnar , LKML , Paul Turner , Andrew Morton , alex.shi@intel.com, Ram Pai , "Nikunj A. Dadhania" , Namhyung Kim Subject: Re: [RFC PATCH v3 0/3] sched: simplify the select_task_rq_fair() References: <51079178.3070002@linux.vnet.ibm.com> <20130220104958.GA9152@gmail.com> <5125A7C8.8020308@linux.vnet.ibm.com> <1361442055.26780.3.camel@laptop> <5126D9E0.7040108@linux.vnet.ibm.com> <1361509697.5817.65.camel@marge.simpson.net> In-Reply-To: <1361509697.5817.65.camel@marge.simpson.net> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit X-Content-Scanned: Fidelis XPS MAILER x-cbid: 13022206-5816-0000-0000-000006C8C818 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 02/22/2013 01:08 PM, Mike Galbraith wrote: > On Fri, 2013-02-22 at 10:37 +0800, Michael Wang wrote: > >> According to the testing result, I could not agree this purpose of >> wake_affine() benefit us, but I'm sure that wake_affine() is a terrible >> performance killer when system is busy. > > (hm, result is singular.. pgbench in 1:N mode only?) I'm not sure about how pgbench implemented, all I know is it will create several instance and access the database, I suppose no different from several threads access database (1 server and N clients?). There are improvement since when system busy, wake_affine() will be skipped. And in old world, when system is busy, wake_affine() will only be skipped if prev_cpu and curr_cpu belong to different nodes. 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/ >