From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753259Ab1AZMfY (ORCPT ); Wed, 26 Jan 2011 07:35:24 -0500 Received: from casper.infradead.org ([85.118.1.10]:43197 "EHLO casper.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753125Ab1AZMfX convert rfc822-to-8bit (ORCPT ); Wed, 26 Jan 2011 07:35:23 -0500 Subject: Re: [tip:sched/core] sched: Avoid expensive initial update_cfs_load() From: Peter Zijlstra To: mingo@redhat.com, hpa@zytor.com, linux-kernel@vger.kernel.org, pjt@google.com, tglx@linutronix.de, mingo@elte.hu Cc: linux-tip-commits@vger.kernel.org In-Reply-To: References: <20110122044852.102126037@google.com> Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 8BIT Date: Wed, 26 Jan 2011 13:36:03 +0100 Message-ID: <1296045363.28776.1153.camel@laptop> Mime-Version: 1.0 X-Mailer: Evolution 2.30.3 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, 2011-01-26 at 12:11 +0000, tip-bot for Paul Turner wrote: > index e0fa3ff..6820b5b 100644 > --- a/kernel/sched.c > +++ b/kernel/sched.c > @@ -7796,6 +7796,8 @@ static void init_cfs_rq(struct cfs_rq *cfs_rq, > struct rq *rq) > INIT_LIST_HEAD(&cfs_rq->tasks); > #ifdef CONFIG_FAIR_GROUP_SCHED > cfs_rq->rq = rq; > + /* allow initial update_cfs_load() to truncate */ > + cfs_rq->load_stamp = 1; > #endif > cfs_rq->min_vruntime = (u64)(-(1LL << 20)); > } That wants a fix to build on UP, --- Index: linux-2.6/kernel/sched.c =================================================================== --- linux-2.6.orig/kernel/sched.c +++ linux-2.6/kernel/sched.c @@ -7797,8 +7797,10 @@ static void init_cfs_rq(struct cfs_rq *c #ifdef CONFIG_FAIR_GROUP_SCHED cfs_rq->rq = rq; /* allow initial update_cfs_load() to truncate */ +#ifdef CONFIG_SMP cfs_rq->load_stamp = 1; #endif +#endif cfs_rq->min_vruntime = (u64)(-(1LL << 20)); }