Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932232Ab3DBOav (ORCPT ); Tue, 2 Apr 2013 10:30:51 -0400 Received: from mail-bk0-f43.google.com ([209.85.214.43]:58362 "EHLO mail-bk0-f43.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1761170Ab3DBOau (ORCPT ); Tue, 2 Apr 2013 10:30:50 -0400 MIME-Version: 1.0 In-Reply-To: <1364654108-16307-4-git-send-email-alex.shi@intel.com> References: <1364654108-16307-1-git-send-email-alex.shi@intel.com> <1364654108-16307-4-git-send-email-alex.shi@intel.com> Date: Tue, 2 Apr 2013 16:30:48 +0200 Message-ID: Subject: Re: [patch v6 03/21] sched: only count runnable avg on cfs_rq's nr_running From: Vincent Guittot To: Alex Shi 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 Content-Type: text/plain; charset=ISO-8859-1 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1352 Lines: 38 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. Vincent > inc_nr_running(rq); > } > hrtick_update(rq); > -- > 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/