From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752993Ab1ASMwu (ORCPT ); Wed, 19 Jan 2011 07:52:50 -0500 Received: from smtp.nokia.com ([147.243.1.47]:54684 "EHLO mgw-sa01.nokia.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752458Ab1ASMwt (ORCPT ); Wed, 19 Jan 2011 07:52:49 -0500 Subject: Re: Bug in scheduler when using rt_mutex From: Onkalo Samu Reply-To: samu.p.onkalo@nokia.com To: ext Peter Zijlstra Cc: Yong Zhang , mingo@elte.hu, "linux-kernel@vger.kernel.org" , tglx , "Onkalo Samu.P" In-Reply-To: <1295436632.30950.1542.camel@laptop> References: <1295275365.12840.13.camel@kolo> <1295280032.30950.128.camel@laptop> <1295339012.11678.35.camel@kolo> <1295357746.30950.681.camel@laptop> <1295430276.30950.1414.camel@laptop> <1295433498.30950.1482.camel@laptop> <1295436632.30950.1542.camel@laptop> Content-Type: text/plain; charset="UTF-8" Organization: Nokia Oyj Date: Wed, 19 Jan 2011 14:58:01 +0200 Message-ID: <1295441881.11678.41.camel@kolo> Mime-Version: 1.0 X-Mailer: Evolution 2.28.3 Content-Transfer-Encoding: 7bit X-Nokia-AV: Clean Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, 2011-01-19 at 12:30 +0100, ext Peter Zijlstra wrote: > On Wed, 2011-01-19 at 11:38 +0100, Peter Zijlstra wrote: > > > Hrm, I think the to bit is not needed with the from thing in place, the > > enqueue from _setprio will already have added min_vruntime > > > Would lead to something like this: > Doesn't work in my case. > --- > Index: linux-2.6/kernel/sched.c > =================================================================== > --- linux-2.6.orig/kernel/sched.c > +++ linux-2.6/kernel/sched.c > @@ -8108,6 +8108,8 @@ EXPORT_SYMBOL(__might_sleep); > #ifdef CONFIG_MAGIC_SYSRQ > static void normalize_task(struct rq *rq, struct task_struct *p) > { > + struct sched_class *prev_class = p->sched_class; > + int old_prio = p->prio; > int on_rq; > > on_rq = p->se.on_rq; > @@ -8118,6 +8120,8 @@ static void normalize_task(struct rq *rq > activate_task(rq, p, 0); > resched_task(rq->curr); > } > + > + check_class_changed(rq, p, prev_class, old_prio, task_current(rq, p)); > } > > void normalize_rt_tasks(void) > Index: linux-2.6/kernel/sched_fair.c > =================================================================== > --- linux-2.6.orig/kernel/sched_fair.c > +++ linux-2.6/kernel/sched_fair.c > @@ -4066,11 +4066,30 @@ static void prio_changed_fair(struct rq > check_preempt_curr(rq, p, 0); > } > > +static void > +switched_from_fair(struct rq *rq, struct task_struct *p, int running) > +{ > + struct sched_entity *se = &p->se; > + struct cfs_rq *cfs_rq = cfs_rq_of(se); > + > + /* > + * Ensure the task's vruntime is normalized, so that when its > + * switched back to the fair class the enqueue_entity(.flags=0) will > + * do the right thing. > + * > + * If it was on_rq, then the dequeue_entity(.flags=0) will already > + * have normalized the vruntime, if it was !on_rq, then only when > + * the task is sleeping will it still have non-normalized vruntime. > + */ > + if (!se->on_rq && p->state != TASK_RUNNING) > + se->vruntime -= cfs_rq->min_vruntime; > +} > + > /* > * We switched to the sched_fair class. > */ > -static void switched_to_fair(struct rq *rq, struct task_struct *p, > - int running) > +static void > +switched_to_fair(struct rq *rq, struct task_struct *p, int running) > { > /* > * We were most likely switched from sched_rt, so > @@ -4163,6 +4182,7 @@ static const struct sched_class fair_sch > .task_fork = task_fork_fair, > > .prio_changed = prio_changed_fair, > + .switched_from = switched_from_fair, > .switched_to = switched_to_fair, > > .get_rr_interval = get_rr_interval_fair, >