From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S934606AbaE2OCP (ORCPT ); Thu, 29 May 2014 10:02:15 -0400 Received: from bombadil.infradead.org ([198.137.202.9]:36298 "EHLO bombadil.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932867AbaE2OCN (ORCPT ); Thu, 29 May 2014 10:02:13 -0400 Date: Thu, 29 May 2014 16:02:04 +0200 From: Peter Zijlstra To: Vincent Guittot Cc: mingo@kernel.org, linux-kernel@vger.kernel.org, linux@arm.linux.org.uk, linux-arm-kernel@lists.infradead.org, preeti@linux.vnet.ibm.com, Morten.Rasmussen@arm.com, efault@gmx.de, nicolas.pitre@linaro.org, linaro-kernel@lists.linaro.org, daniel.lezcano@linaro.org Subject: Re: [PATCH v2 11/11] sched: replace capacity by activity Message-ID: <20140529140204.GH11074@laptop.programming.kicks-ass.net> References: <1400860385-14555-1-git-send-email-vincent.guittot@linaro.org> <1400860385-14555-12-git-send-email-vincent.guittot@linaro.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1400860385-14555-12-git-send-email-vincent.guittot@linaro.org> User-Agent: Mutt/1.5.21 (2012-12-30) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, May 23, 2014 at 05:53:05PM +0200, Vincent Guittot wrote: > @@ -6052,8 +6006,8 @@ static inline void update_sd_lb_stats(struct lb_env *env, struct sd_lb_stats *sd > * with a large weight task outweighs the tasks on the system). > */ > if (prefer_sibling && sds->local && > - sds->local_stat.group_has_capacity) > - sgs->group_capacity = min(sgs->group_capacity, 1U); > + sds->local_stat.group_capacity > 0) > + sgs->group_capacity = min(sgs->group_capacity, 1L); > > if (update_sd_pick_busiest(env, sds, sg, sgs)) { > sds->busiest = sg; > @@ -6228,7 +6182,7 @@ static inline void calculate_imbalance(struct lb_env *env, struct sd_lb_stats *s > * have to drop below capacity to reach cpu-load equilibrium. > */ > load_above_capacity = > - (busiest->sum_nr_running - busiest->group_capacity); > + (busiest->sum_nr_running - busiest->group_weight); > > load_above_capacity *= (SCHED_LOAD_SCALE * SCHED_POWER_SCALE); > load_above_capacity /= busiest->group_power; I think you just broke PREFER_SIBLING here.. So we want PREFER_SIBLING to work on nr_running, not utilization because we want to spread single tasks around, regardless of their utilization.