Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752367Ab2JGHpe (ORCPT ); Sun, 7 Oct 2012 03:45:34 -0400 Received: from mail-wi0-f172.google.com ([209.85.212.172]:61716 "EHLO mail-wi0-f172.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752178Ab2JGHon (ORCPT ); Sun, 7 Oct 2012 03:44:43 -0400 From: Vincent Guittot To: linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linaro-dev@lists.linaro.org, peterz@infradead.org, mingo@redhat.com, pjt@google.com, linux@arm.linux.org.uk Cc: Vincent Guittot Subject: [RFC 5/6] sched: pack the idle load balance Date: Sun, 7 Oct 2012 09:43:57 +0200 Message-Id: <1349595838-31274-6-git-send-email-vincent.guittot@linaro.org> X-Mailer: git-send-email 1.7.9.5 In-Reply-To: <1349595838-31274-1-git-send-email-vincent.guittot@linaro.org> References: <1349595838-31274-1-git-send-email-vincent.guittot@linaro.org> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1320 Lines: 47 Look for an idle CPU close the pack buddy CPU whenever possible. The goal is to prevent the wake up of a CPU which doesn't share the power line of the pack 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 6df53b5..f76acdc 100644 --- a/kernel/sched/fair.c +++ b/kernel/sched/fair.c @@ -5158,7 +5158,25 @@ 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 -- 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/