From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757170AbYLPHst (ORCPT ); Tue, 16 Dec 2008 02:48:49 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1754689AbYLPHry (ORCPT ); Tue, 16 Dec 2008 02:47:54 -0500 Received: from casper.infradead.org ([85.118.1.10]:46935 "EHLO casper.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754377AbYLPHrx (ORCPT ); Tue, 16 Dec 2008 02:47:53 -0500 Message-Id: <20081216074636.002108651@chello.nl> References: <20081216074529.570706654@chello.nl> User-Agent: quilt/0.46-1 Date: Tue, 16 Dec 2008 08:45:30 +0100 From: Peter Zijlstra To: mingo@elte.hu, efault@gmx.de Cc: linux-kernel@vger.kernel.org, Peter Zijlstra Subject: [PATCH 1/3] From: Mike Galbraith Content-Disposition: inline; filename=sched-fix-wakeup-clock.patch X-Bad-Reply: References but no 'Re:' in Subject. Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Mike Galbraith It was possible to do the preemption check against an old time stamp. Signed-off-by: Mike Galbraith Signed-off-by: Peter Zijlstra --- kernel/sched.c | 2 +- kernel/sched_fair.c | 7 +++---- 2 files changed, 4 insertions(+), 5 deletions(-) diff --git a/kernel/sched.c b/kernel/sched.c index ce55b6a..efe5c6d 100644 --- a/kernel/sched.c +++ b/kernel/sched.c @@ -2259,6 +2259,7 @@ static int try_to_wake_up(struct task_struct *p, unsigned int state, int sync) smp_wmb(); rq = task_rq_lock(p, &flags); + update_rq_clock(rq); old_state = p->state; if (!(old_state & state)) goto out; @@ -2316,7 +2317,6 @@ out_activate: schedstat_inc(p, se.nr_wakeups_local); else schedstat_inc(p, se.nr_wakeups_remote); - update_rq_clock(rq); activate_task(rq, p, 1); success = 1; diff --git a/kernel/sched_fair.c b/kernel/sched_fair.c index 08ffffd..6ae5115 100644 --- a/kernel/sched_fair.c +++ b/kernel/sched_fair.c @@ -1343,12 +1343,11 @@ static void check_preempt_wakeup(struct rq *rq, struct task_struct *p, int sync) { struct task_struct *curr = rq->curr; struct sched_entity *se = &curr->se, *pse = &p->se; + struct cfs_rq *cfs_rq = task_cfs_rq(curr); - if (unlikely(rt_prio(p->prio))) { - struct cfs_rq *cfs_rq = task_cfs_rq(curr); + update_curr(cfs_rq); - update_rq_clock(rq); - update_curr(cfs_rq); + if (unlikely(rt_prio(p->prio))) { resched_task(curr); return; } --