Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S935411Ab3DJGIk (ORCPT ); Wed, 10 Apr 2013 02:08:40 -0400 Received: from e23smtp07.au.ibm.com ([202.81.31.140]:34042 "EHLO e23smtp07.au.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S934966Ab3DJGIj (ORCPT ); Wed, 10 Apr 2013 02:08:39 -0400 Message-ID: <51650185.9060905@linux.vnet.ibm.com> Date: Wed, 10 Apr 2013 14:07:01 +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: Vincent Guittot CC: Alex Shi , "mingo@redhat.com" , Peter Zijlstra , Thomas Gleixner , Andrew Morton , Arjan van de Ven , Borislav Petkov , Paul Turner , Namhyung Kim , Mike Galbraith , Morten Rasmussen , gregkh@linuxfoundation.org, Preeti U Murthy , Viresh Kumar , linux-kernel , Len Brown , rafael.j.wysocki@intel.com, jkosina@suse.cz, clark.williams@gmail.com, "tony.luck@intel.com" , keescook@chromium.org, mgorman@suse.de, riel@redhat.com Subject: Re: [patch v3 6/8] sched: consider runnable load average in move_tasks References: <1364873008-3169-1-git-send-email-alex.shi@intel.com> <1364873008-3169-7-git-send-email-alex.shi@intel.com> In-Reply-To: Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit X-Content-Scanned: Fidelis XPS MAILER x-cbid: 13041005-0260-0000-0000-000002C89F32 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2492 Lines: 73 On 04/09/2013 03:08 PM, Vincent Guittot wrote: > On 2 April 2013 05:23, Alex Shi wrote: >> Except using runnable load average in background, move_tasks is also >> the key functions in load balance. We need consider the runnable load >> average in it in order to the apple to apple load comparison. >> >> Signed-off-by: Alex Shi >> --- >> kernel/sched/fair.c | 11 ++++++++++- >> 1 file changed, 10 insertions(+), 1 deletion(-) >> >> diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c >> index 1f9026e..bf4e0d4 100644 >> --- a/kernel/sched/fair.c >> +++ b/kernel/sched/fair.c >> @@ -3966,6 +3966,15 @@ static unsigned long task_h_load(struct task_struct *p); >> >> static const unsigned int sched_nr_migrate_break = 32; >> >> +static unsigned long task_h_load_avg(struct task_struct *p) >> +{ >> + u32 period = p->se.avg.runnable_avg_period; >> + if (!period) >> + return 0; >> + >> + return task_h_load(p) * p->se.avg.runnable_avg_sum / period; > > How do you ensure that runnable_avg_period and runnable_avg_sum are > coherent ? an update of the statistic can occur in the middle of your > sequence. Hi, Vincent Don't we have the 'rq->lock' to protect it? move_tasks() was invoked with double locked, for all the se on src and dst rq, no update should happen, isn't it? Regards, Michael Wang > > Vincent > >> +} >> + >> /* >> * move_tasks tries to move up to imbalance weighted load from busiest to >> * this_rq, as part of a balancing operation within domain "sd". >> @@ -4001,7 +4010,7 @@ static int move_tasks(struct lb_env *env) >> if (throttled_lb_pair(task_group(p), env->src_cpu, env->dst_cpu)) >> goto next; >> >> - load = task_h_load(p); >> + load = task_h_load_avg(p); >> >> if (sched_feat(LB_MIN) && load < 16 && !env->sd->nr_balance_failed) >> goto next; >> -- >> 1.7.12 >> > -- > 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/