Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S934027AbbELTjR (ORCPT ); Tue, 12 May 2015 15:39:17 -0400 Received: from foss.arm.com ([217.140.101.70]:34058 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S964815AbbELTjL (ORCPT ); Tue, 12 May 2015 15:39:11 -0400 From: Morten Rasmussen To: peterz@infradead.org, mingo@redhat.com Cc: vincent.guittot@linaro.org, Dietmar Eggemann , yuyang.du@intel.com, preeti@linux.vnet.ibm.com, mturquette@linaro.org, rjw@rjwysocki.net, Juri Lelli , sgurrappadi@nvidia.com, pang.xunlei@zte.com.cn, linux-kernel@vger.kernel.org, linux-pm@vger.kernel.org, morten.rasmussen@arm.com Subject: [RFCv4 PATCH 33/34] sched: Enable idle balance to pull single task towards cpu with higher capacity Date: Tue, 12 May 2015 20:39:08 +0100 Message-Id: <1431459549-18343-34-git-send-email-morten.rasmussen@arm.com> X-Mailer: git-send-email 1.9.1 In-Reply-To: <1431459549-18343-1-git-send-email-morten.rasmussen@arm.com> References: <1431459549-18343-1-git-send-email-morten.rasmussen@arm.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1860 Lines: 55 From: Dietmar Eggemann We do not want to miss out on the ability to pull a single remaining task from a potential source cpu towards an idle destination cpu if the energy aware system operates above the tipping point. Add an extra criteria to need_active_balance() to kick off active load balance if the source cpu is over-utilized and has lower capacity than the destination cpu. cc: Ingo Molnar cc: Peter Zijlstra Signed-off-by: Morten Rasmussen Signed-off-by: Dietmar Eggemann --- kernel/sched/fair.c | 10 +++++++++- 1 file changed, 9 insertions(+), 1 deletion(-) diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c index 83218e0..8efeb1d 100644 --- a/kernel/sched/fair.c +++ b/kernel/sched/fair.c @@ -7527,6 +7527,13 @@ static int need_active_balance(struct lb_env *env) return 1; } + if ((capacity_of(env->src_cpu) < capacity_of(env->dst_cpu)) && + env->src_rq->cfs.h_nr_running == 1 && + cpu_overutilized(env->src_cpu) && + !cpu_overutilized(env->dst_cpu)) { + return 1; + } + return unlikely(sd->nr_balance_failed > sd->cache_nice_tries+2); } @@ -7881,7 +7888,8 @@ static int idle_balance(struct rq *this_rq) this_rq->idle_stamp = rq_clock(this_rq); if (this_rq->avg_idle < sysctl_sched_migration_cost || - !this_rq->rd->overload) { + (!energy_aware() && !this_rq->rd->overload) || + (energy_aware() && !this_rq->rd->overutilized)) { rcu_read_lock(); sd = rcu_dereference_check_sched_domain(this_rq->sd); if (sd) -- 1.9.1 -- 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/