Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932805Ab1BPB5F (ORCPT ); Tue, 15 Feb 2011 20:57:05 -0500 Received: from kroah.org ([198.145.64.141]:49282 "EHLO coco.kroah.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1758572Ab1BPBvh (ORCPT ); Tue, 15 Feb 2011 20:51:37 -0500 X-Mailbox-Line: From gregkh@clark.kroah.org Tue Feb 15 17:47:03 2011 Message-Id: <20110216014703.645328150@clark.kroah.org> User-Agent: quilt/0.48-11.2 Date: Tue, 15 Feb 2011 17:46:00 -0800 From: Greg KH To: linux-kernel@vger.kernel.org, stable@kernel.org Cc: stable-review@kernel.org, torvalds@linux-foundation.org, akpm@linux-foundation.org, alan@lxorguk.ukuu.org.uk, Nikhil Rao , Peter Zijlstra , Ingo Molnar , Mike Galbraith Subject: [094/115] sched: Do not consider SCHED_IDLE tasks to be cache hot In-Reply-To: <20110216014741.GA24678@kroah.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1371 Lines: 41 2.6.32-longterm review patch. If anyone has any objections, please let us know. ------------------ Commit: ef8002f6848236de5adc613063ebeabddea8a6fb upstream 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 Signed-off-by: Greg Kroah-Hartman --- kernel/sched.c | 3 +++ 1 file changed, 3 insertions(+) --- a/kernel/sched.c +++ b/kernel/sched.c @@ -2014,6 +2014,9 @@ task_hot(struct task_struct *p, u64 now, if (p->sched_class != &fair_sched_class) return 0; + if (unlikely(p->policy == SCHED_IDLE)) + return 0; + /* * Buddy candidates are cache hot: */ -- 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/