Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758261Ab3FDDJY (ORCPT ); Mon, 3 Jun 2013 23:09:24 -0400 Received: from e28smtp09.in.ibm.com ([122.248.162.9]:43176 "EHLO e28smtp09.in.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753514Ab3FDDJU (ORCPT ); Mon, 3 Jun 2013 23:09:20 -0400 Message-ID: <51AD5A51.1000808@linux.vnet.ibm.com> Date: Tue, 04 Jun 2013 11:09:05 +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: Alex Shi CC: Peter Zijlstra , Paul Turner , Ingo Molnar , Thomas Gleixner , Andrew Morton , Borislav Petkov , Namhyung Kim , Mike Galbraith , Morten Rasmussen , Vincent Guittot , Preeti U Murthy , Viresh Kumar , LKML , Mel Gorman , Rik van Riel Subject: Re: [DISCUSSION] removing variety rq->cpu_load ? References: <1367804711-30308-1-git-send-email-alex.shi@intel.com> <1367804711-30308-6-git-send-email-alex.shi@intel.com> <20130506101936.GE13861@dyad.programming.kicks-ass.net> <20130506111041.GA15446@dyad.programming.kicks-ass.net> <51889C8A.5000806@intel.com> <51AD46CA.9020609@intel.com> <51AD4808.6020507@intel.com> <51AD51E3.6060307@linux.vnet.ibm.com> <51AD549A.9010903@intel.com> In-Reply-To: <51AD549A.9010903@intel.com> Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit X-TM-AS-MML: No X-Content-Scanned: Fidelis XPS MAILER x-cbid: 13060403-2674-0000-0000-0000093943B9 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2456 Lines: 75 On 06/04/2013 10:44 AM, Alex Shi wrote: > On 06/04/2013 10:33 AM, Michael Wang wrote: >> Hi, Alex >> >> On 06/04/2013 09:51 AM, Alex Shi wrote: >>> resend with a new subject. >> >> Forgive me but I'm a little lost on this thread... >> >> So we are planing to rely on instant 'cpu_load[0]' and decayed >> 'runnable_load_avg' only, do we? > > cpu_load is a kind of time decay for cpu load, but after runnable load introduced, > the decay functionality is a kind duplicate with it. > So, remove them will make code simple. The idea were mentioned by Paul, Peter and I. Nice, what about make a patch 9 and clean up all those stuff? I suppose we will get more benefit :) Regards, Michael Wang > > the following is Peter's word of this affair. > >> Agreed, esp. the plethora of weird idx things we currently have. If we need to >> re-introduce something it would likely only be the busy case and for that we >> can immediately link to the balance interval or so. > > >> >> >> Regards, >> Michael Wang >> >>> >>>> Peter, >>>> >>>> I just tried to remove the variety rq.cpu_load, by the following patch. >>>> Because forkexec_idx and busy_idx are all zero, after the patch system just keep cpu_load[0] >>>> and remove other values. >>>> I tried the patch base 3.10-rc3 and latest tip/sched/core with benchmark dbench,tbench, >>>> aim7,hackbench. and oltp of sysbench. Seems performance doesn't change clear. >>>> So, for my tested machines, core2, NHM, SNB, with 2 or 4 CPU sockets, and above tested >>>> benchmark. We are fine to remove the variety cpu_load. >>>> Don't know if there some other concerns on other scenarios. >>>> >>>> --- >>>> diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c >>>> index 590d535..f0ca983 100644 >>>> --- a/kernel/sched/fair.c >>>> +++ b/kernel/sched/fair.c >>>> @@ -4626,7 +4626,7 @@ static inline void update_sd_lb_stats(struct lb_env *env, >>>> if (child && child->flags & SD_PREFER_SIBLING) >>>> prefer_sibling = 1; >>>> >>>> - load_idx = get_sd_load_idx(env->sd, env->idle); >>>> + load_idx = 0; //get_sd_load_idx(env->sd, env->idle); >>>> >>>> do { >>>> int local_group; >>>> >>>> >>> >>> >> > > -- 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/