From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753535Ab1GGFdM (ORCPT ); Thu, 7 Jul 2011 01:33:12 -0400 Received: from smtp-out.google.com ([216.239.44.51]:49075 "EHLO smtp-out.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752823Ab1GGFdL (ORCPT ); Thu, 7 Jul 2011 01:33:11 -0400 DomainKey-Signature: a=rsa-sha1; s=beta; d=google.com; c=nofws; q=dns; h=message-id:user-agent:date:from:to:cc:subject:references:content-disposition; b=CBqOF+LKIOJC40SogBIRILz3AU0U7VlJ4gLhs5B9k6I62nEBFvw71Gq1pCLgV9mkD Cq6fnq0gdpHqGOQpPhnXQ== Message-Id: <20110707053059.797714697@google.com> User-Agent: quilt/0.48-1 Date: Wed, 06 Jul 2011 22:30:37 -0700 From: Paul Turner To: linux-kernel@vger.kernel.org Cc: Peter Zijlstra , Bharata B Rao , Dhaval Giani , Balbir Singh , Vaidyanathan Srinivasan , Srivatsa Vaddagiri , Kamalesh Babulal , Hidetoshi Seto , Ingo Molnar , Pavel Emelyanov , Hu Tao Subject: [patch 01/17] sched: (fixlet) dont update shares twice on on_rq parent References: <20110707053036.173186930@google.com> Content-Disposition: inline; filename=sched-bwc-fix_dequeue_task_buglet.patch Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org In dequeue_task_fair() we bail on dequeue when we encounter a parenting entity with additional weight. However, we perform a double shares update on this entity as we continue the shares update traversal from this point, despite dequeue_entity() having already updated its queuing cfs_rq. Avoid this by starting from the parent when we resume. Signed-off-by: Paul Turner --- kernel/sched_fair.c | 3 +++ 1 file changed, 3 insertions(+) Index: tip/kernel/sched_fair.c =================================================================== --- tip.orig/kernel/sched_fair.c +++ tip/kernel/sched_fair.c @@ -1370,6 +1370,9 @@ static void dequeue_task_fair(struct rq */ if (task_sleep && parent_entity(se)) set_next_buddy(parent_entity(se)); + + /* avoid re-evaluating load for this entity */ + se = parent_entity(se); break; } flags |= DEQUEUE_SLEEP;