From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752879AbaINTvM (ORCPT ); Sun, 14 Sep 2014 15:51:12 -0400 Received: from casper.infradead.org ([85.118.1.10]:44003 "EHLO casper.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752841AbaINTvK (ORCPT ); Sun, 14 Sep 2014 15:51:10 -0400 Date: Sun, 14 Sep 2014 21:51:02 +0200 From: Peter Zijlstra To: Vincent Guittot Cc: Ingo Molnar , linux-kernel , Preeti U Murthy , Russell King - ARM Linux , LAK , Rik van Riel , Morten Rasmussen , Mike Galbraith , Nicolas Pitre , "linaro-kernel@lists.linaro.org" , Daniel Lezcano , Dietmar Eggemann Subject: Re: [PATCH v5 11/12] sched: replace capacity_factor by utilization Message-ID: <20140914195102.GA3037@worktop.localdomain> References: <1409051215-16788-1-git-send-email-vincent.guittot@linaro.org> <1409051215-16788-12-git-send-email-vincent.guittot@linaro.org> <20140911161517.GA3190@worktop.ger.corp.intel.com> <20140914194156.GC2832@worktop.localdomain> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20140914194156.GC2832@worktop.localdomain> User-Agent: Mutt/1.5.22.1 (2013-10-16) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Sun, Sep 14, 2014 at 09:41:56PM +0200, Peter Zijlstra wrote: > On Thu, Sep 11, 2014 at 07:26:48PM +0200, Vincent Guittot wrote: > > On 11 September 2014 18:15, Peter Zijlstra wrote: > > > On Tue, Aug 26, 2014 at 01:06:54PM +0200, Vincent Guittot wrote: > > >> +static inline int group_has_free_capacity(struct sg_lb_stats *sgs, > > >> + struct lb_env *env) > > >> { > > >> + if ((sgs->group_capacity_orig * 100) > > > >> + (sgs->group_utilization * env->sd->imbalance_pct)) > > >> + return 1; > > >> + > > >> + if (sgs->sum_nr_running < sgs->group_weight) > > >> + return 1; > > >> > > >> + return 0; > > >> +} > > >> > > >> +static inline int group_is_overloaded(struct sg_lb_stats *sgs, > > >> + struct lb_env *env) > > >> +{ > > >> + if (sgs->sum_nr_running <= sgs->group_weight) > > >> + return 0; > > >> > > >> + if ((sgs->group_capacity_orig * 100) < > > >> + (sgs->group_utilization * env->sd->imbalance_pct)) > > >> + return 1; > > >> > > >> + return 0; > > >> } > > > > > > I'm confused about the utilization vs capacity_orig. I see how we should > > > > 1st point is that I should compare utilization vs capacity and not > > capacity_orig. > > I should have replaced capacity_orig by capacity in the functions > > above when i move the utilization statistic from > > rq->avg.runnable_avg_sum to cfs.usage_load_avg. > > rq->avg.runnable_avg_sum was measuring all activity on the cpu whereas > > cfs.usage_load_avg integrates only cfs tasks > > > > With this change, we don't need sgs->group_capacity_orig anymore but > > only sgs->group_capacity. So sgs->group_capacity_orig can be removed > > as it's no more used in the code as sg_capacity_factor has been > > removed > > Yes, but.. so I suppose we need to add DVFS accounting and remove > cpufreq from the capacity thing. Otherwise I don't see it make sense. That is to say, please also explain these details in the changelog, and preferably also in a XXX/FIXME/TODO comment near wherever so we don't forget about it.