From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752012AbcF0Ih2 (ORCPT ); Mon, 27 Jun 2016 04:37:28 -0400 Received: from merlin.infradead.org ([205.233.59.134]:53011 "EHLO merlin.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751655AbcF0IhY (ORCPT ); Mon, 27 Jun 2016 04:37:24 -0400 Date: Mon, 27 Jun 2016 10:37:21 +0200 From: Peter Zijlstra To: Jisheng Zhang Cc: mingo@redhat.com, rafael.j.wysocki@intel.com, linux-kernel@vger.kernel.org Subject: Re: [PATCH] sched/fair: avoid !CONFIG_SMP cpufreq update callbacks when go idle Message-ID: <20160627083721.GY30154@twins.programming.kicks-ass.net> References: <1467014163-1517-1-git-send-email-jszhang@marvell.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1467014163-1517-1-git-send-email-jszhang@marvell.com> User-Agent: Mutt/1.5.23.1 (2014-03-12) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Jun 27, 2016 at 03:56:03PM +0800, Jisheng Zhang wrote: > This is to avoid cpufreq update callbacks when we go idle on UP > platforms. How so? the patch only avoids calling the update for (!root) cgroups -- which makes sense, but I'm not seeing how that's related to going idle, or UP at all. > > Signed-off-by: Jisheng Zhang > --- > kernel/sched/fair.c | 3 ++- > 1 file changed, 2 insertions(+), 1 deletion(-) > > diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c > index bdcbeea..236ec5b 100644 > --- a/kernel/sched/fair.c > +++ b/kernel/sched/fair.c > @@ -3121,7 +3121,8 @@ static inline void update_load_avg(struct sched_entity *se, int not_used) > struct cfs_rq *cfs_rq = cfs_rq_of(se); > struct rq *rq = rq_of(cfs_rq); > > - cpufreq_trigger_update(rq_clock(rq)); > + if (&rq->cfs == cfs_rq) > + cpufreq_trigger_update(rq_clock(rq)); > } > > static inline void > -- > 2.8.1 >