From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S965301AbZLQS7b (ORCPT ); Thu, 17 Dec 2009 13:59:31 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1759604AbZLQS7I (ORCPT ); Thu, 17 Dec 2009 13:59:08 -0500 Received: from casper.infradead.org ([85.118.1.10]:60921 "EHLO casper.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757128AbZLQS7G (ORCPT ); Thu, 17 Dec 2009 13:59:06 -0500 Message-Id: <20091217185430.655230380@chello.nl> References: <20091217185021.684424629@chello.nl> User-Agent: quilt/0.46-1 Date: Thu, 17 Dec 2009 19:50:27 +0100 From: Peter Zijlstra To: Ingo Molnar Cc: Mike Galbraith , LKML , Peter Zijlstra Subject: [PATCH 6/6] sched: Add a lock break for PREEMPT=y Content-Disposition: inline; filename=sched-lb-6.patch Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Since load-balancing can hold rq->locks for quite a long while, allow breaking out early when there is lock contention. Signed-off-by: Peter Zijlstra --- kernel/sched_fair.c | 4 ++++ 1 file changed, 4 insertions(+) Index: linux-2.6/kernel/sched_fair.c =================================================================== --- linux-2.6.orig/kernel/sched_fair.c +++ linux-2.6/kernel/sched_fair.c @@ -2065,6 +2065,10 @@ static int move_tasks(struct rq *this_rq */ if (idle == CPU_NEWLY_IDLE && this_rq->nr_running) break; + + if (raw_spin_is_contended(&this_rq->lock) || + raw_spin_is_contended(&busiest->lock)) + break; #endif } while (load_moved && max_load_move > total_load_moved); --