From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1759149Ab3DCBDI (ORCPT ); Tue, 2 Apr 2013 21:03:08 -0400 Received: from mga11.intel.com ([192.55.52.93]:3215 "EHLO mga11.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1759053Ab3DCBDG (ORCPT ); Tue, 2 Apr 2013 21:03:06 -0400 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="4.87,396,1363158000"; d="scan'208";a="316003360" Message-ID: <515B7F99.3000407@intel.com> Date: Wed, 03 Apr 2013 09:02:17 +0800 From: Alex Shi User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:17.0) Gecko/20130221 Thunderbird/17.0.3 MIME-Version: 1.0 To: Vincent Guittot CC: "mingo@redhat.com" , Peter Zijlstra , Thomas Gleixner , Andrew Morton , Arjan van de Ven , Borislav Petkov , Paul Turner , Namhyung Kim , Mike Galbraith , gregkh@linuxfoundation.org, Preeti U Murthy , Viresh Kumar , linux-kernel Subject: Re: [patch v6 03/21] sched: only count runnable avg on cfs_rq's nr_running References: <1364654108-16307-1-git-send-email-alex.shi@intel.com> <1364654108-16307-4-git-send-email-alex.shi@intel.com> In-Reply-To: Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 04/02/2013 10:30 PM, Vincent Guittot wrote: > On 30 March 2013 15:34, Alex Shi wrote: >> Old function count the runnable avg on rq's nr_running even there is >> only rt task in rq. That is incorrect, so correct it to cfs_rq's >> nr_running. >> >> Signed-off-by: Alex Shi >> --- >> kernel/sched/fair.c | 2 +- >> 1 file changed, 1 insertion(+), 1 deletion(-) >> >> diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c >> index 2881d42..026e959 100644 >> --- a/kernel/sched/fair.c >> +++ b/kernel/sched/fair.c >> @@ -2829,7 +2829,7 @@ enqueue_task_fair(struct rq *rq, struct task_struct *p, int flags) >> } >> >> if (!se) { >> - update_rq_runnable_avg(rq, rq->nr_running); >> + update_rq_runnable_avg(rq, rq->cfs.nr_running); > > A RT task that preempts your CFS task will be accounted in the > runnable_avg fields. So whatever you do, RT task will impact your > runnable_avg statistics. Instead of trying to get only CFS tasks, you > should take into account all tasks activity in the rq. Thanks for comments, Vincent! Yes, I know some rt task time was counted into cfs, but now we have no good idea to remove them clearly. So I just want to a bit more precise cfs runnable load here. On the other side, periodic LB balance on combined the cfs/rt load, but removed the RT utilisation in cpu_power. So, PJT, Peter, what's your idea of this point? > > Vincent >> inc_nr_running(rq); >> } >> hrtick_update(rq); >> -- >> 1.7.12 >> -- Thanks Alex