From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754160Ab2LLNci (ORCPT ); Wed, 12 Dec 2012 08:32:38 -0500 Received: from mail-wg0-f46.google.com ([74.125.82.46]:60599 "EHLO mail-wg0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753966Ab2LLNcg (ORCPT ); Wed, 12 Dec 2012 08:32:36 -0500 From: Vincent Guittot To: linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linaro-dev@lists.linaro.org, peterz@infradead.org, mingo@kernel.org, linux@arm.linux.org.uk, pjt@google.com, santosh.shilimkar@ti.com, Morten.Rasmussen@arm.com, chander.kashyap@linaro.org, cmetcalf@tilera.com, tony.luck@intel.com Cc: alex.shi@intel.com, preeti@linux.vnet.ibm.com, paulmck@linux.vnet.ibm.com, tglx@linutronix.de, len.brown@intel.com, arjan@linux.intel.com, amit.kucheria@linaro.org, viresh.kumar@linaro.org, Vincent Guittot Subject: [RFC PATCH v2 5/6] sched: pack the idle load balance Date: Wed, 12 Dec 2012 14:31:31 +0100 Message-Id: <1355319092-30980-6-git-send-email-vincent.guittot@linaro.org> X-Mailer: git-send-email 1.7.9.5 In-Reply-To: <1355319092-30980-1-git-send-email-vincent.guittot@linaro.org> References: <1355319092-30980-1-git-send-email-vincent.guittot@linaro.org> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Look for an idle CPU close to the pack buddy CPU whenever possible. The goal is to prevent the wake up of a CPU which doesn't share the power domain of the pack buddy CPU. Signed-off-by: Vincent Guittot --- kernel/sched/fair.c | 18 ++++++++++++++++++ 1 file changed, 18 insertions(+) diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c index f1a4c24..6475f54 100644 --- a/kernel/sched/fair.c +++ b/kernel/sched/fair.c @@ -7274,7 +7274,25 @@ static struct { static inline int find_new_ilb(int call_cpu) { + struct sched_domain *sd; int ilb = cpumask_first(nohz.idle_cpus_mask); + int buddy = per_cpu(sd_pack_buddy, call_cpu); + + /* + * If we have a pack buddy CPU, we try to run load balance on a CPU + * that is close to the buddy. + */ + if (buddy != -1) + for_each_domain(buddy, sd) { + if (sd->flags & SD_SHARE_CPUPOWER) + continue; + + ilb = cpumask_first_and(sched_domain_span(sd), + nohz.idle_cpus_mask); + + if (ilb < nr_cpu_ids) + break; + } if (ilb < nr_cpu_ids && idle_cpu(ilb)) return ilb; -- 1.7.9.5