Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756210Ab1C3Vwo (ORCPT ); Wed, 30 Mar 2011 17:52:44 -0400 Received: from mga02.intel.com ([134.134.136.20]:51403 "EHLO mga02.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933402Ab1C3VHN (ORCPT ); Wed, 30 Mar 2011 17:07:13 -0400 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="4.63,270,1299484800"; d="scan'208";a="621236907" From: Andi Kleen References: <20110330203.501921634@firstfloor.org> In-Reply-To: <20110330203.501921634@firstfloor.org> To: ncrao@google.com, a.p.zijlstra@chello.nl, ak@linux.intel.com, mingo@elte.hu, efault@gmx.de, gregkh@suse.de, linux-kernel@vger.kernel.org, stable@kernel.org, tim.bird@am.sony.com Subject: [PATCH] [93/275] sched: Do not consider SCHED_IDLE tasks to be cache hot Message-Id: <20110330210531.8B7AE3E1A05@tassilo.jf.intel.com> Date: Wed, 30 Mar 2011 14:05:31 -0700 (PDT) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1582 Lines: 41 2.6.35-longterm review patch. If anyone has any objections, please let me 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 Signed-off-by: Andi Kleen 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(+) Index: linux-2.6.35.y/kernel/sched.c =================================================================== --- linux-2.6.35.y.orig/kernel/sched.c 2011-03-29 23:02:59.968300981 -0700 +++ linux-2.6.35.y/kernel/sched.c 2011-03-29 23:55:02.689398361 -0700 @@ -1972,6 +1972,9 @@ 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/