From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756496Ab1BJMaA (ORCPT ); Thu, 10 Feb 2011 07:30:00 -0500 Received: from cantor.suse.de ([195.135.220.2]:33729 "EHLO mx1.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755427Ab1BJMYy (ORCPT ); Thu, 10 Feb 2011 07:24:54 -0500 From: stable-bot for Nikhil Rao Date: Thu, 10 Feb 2011 10:23:25 +0100 Subject: [PATCH 09/28] sched: Do not consider SCHED_IDLE tasks to be cache hot To: stable@kernel.org Cc: linux-kernel@vger.kernel.org, Peter Zijlstra , Ingo Molnar Message-ID: <1297340643.5512.9.camel@marge.simson.net> Mime-Version: 1.0 X-Mailer: Evolution 2.30.1.2 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Commit: ef8002f6848236de5adc613063ebeabddea8a6fb upstream Author: Nikhil Rao AuthorDate: Wed Oct 13 12:09:35 2010 -0700 This patch adds a check in task_hot to return if the task has SCHED_IDLE policy. SCHED_IDLE tasks have very low weight, and when run with regular workloads, are typically scheduled many milliseconds apart. There is no need to consider these tasks hot for load balancing. Signed-off-by: Nikhil Rao Signed-off-by: Peter Zijlstra LKML-Reference: <1287173550-30365-2-git-send-email-ncrao@google.com> Signed-off-by: Ingo Molnar Signed-off-by: Mike Galbraith Acked-by: Peter Zijlstra --- kernel/sched.c | 3 +++ 1 files changed, 3 insertions(+), 0 deletions(-) diff --git a/kernel/sched.c b/kernel/sched.c index 87e3b2b..0a1fb24 100644 --- a/kernel/sched.c +++ b/kernel/sched.c @@ -2014,6 +2014,9 @@ task_hot(struct task_struct *p, u64 now, struct sched_domain *sd) if (p->sched_class != &fair_sched_class) return 0; + if (unlikely(p->policy == SCHED_IDLE)) + return 0; + /* * Buddy candidates are cache hot: */ -- 1.7.4