From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754342Ab1E1QgS (ORCPT ); Sat, 28 May 2011 12:36:18 -0400 Received: from hera.kernel.org ([140.211.167.34]:32836 "EHLO hera.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752312Ab1E1QgQ (ORCPT ); Sat, 28 May 2011 12:36:16 -0400 Date: Sat, 28 May 2011 16:35:56 GMT From: tip-bot for KOSAKI Motohiro Message-ID: Cc: linux-kernel@vger.kernel.org, hpa@zytor.com, mingo@redhat.com, a.p.zijlstra@chello.nl, oleg@redhat.com, tglx@linutronix.de, kosaki.motohiro@jp.fujitsu.com, mingo@elte.hu Reply-To: mingo@redhat.com, hpa@zytor.com, linux-kernel@vger.kernel.org, a.p.zijlstra@chello.nl, tglx@linutronix.de, oleg@redhat.com, kosaki.motohiro@jp.fujitsu.com, mingo@elte.hu In-Reply-To: <4DD4B3FA.5060901@jp.fujitsu.com> References: <4DD4B3FA.5060901@jp.fujitsu.com> To: linux-tip-commits@vger.kernel.org Subject: [tip:sched/urgent] cpuset: Fix cpuset_cpus_allowed_fallback(), don't update tsk->rt.nr_cpus_allowed Git-Commit-ID: 1e1b6c511d1b23cb7c3b619d82fc7bd9f620565d X-Mailer: tip-git-log-daemon Robot-ID: Robot-Unsubscribe: Contact to get blacklisted from these emails MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Disposition: inline X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.2.3 (hera.kernel.org [127.0.0.1]); Sat, 28 May 2011 16:35:57 +0000 (UTC) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Commit-ID: 1e1b6c511d1b23cb7c3b619d82fc7bd9f620565d Gitweb: http://git.kernel.org/tip/1e1b6c511d1b23cb7c3b619d82fc7bd9f620565d Author: KOSAKI Motohiro AuthorDate: Thu, 19 May 2011 15:08:58 +0900 Committer: Ingo Molnar CommitDate: Sat, 28 May 2011 17:02:57 +0200 cpuset: Fix cpuset_cpus_allowed_fallback(), don't update tsk->rt.nr_cpus_allowed The rule is, we have to update tsk->rt.nr_cpus_allowed if we change tsk->cpus_allowed. Otherwise RT scheduler may confuse. Signed-off-by: KOSAKI Motohiro Cc: Oleg Nesterov Signed-off-by: Peter Zijlstra Link: http://lkml.kernel.org/r/4DD4B3FA.5060901@jp.fujitsu.com Signed-off-by: Ingo Molnar --- include/linux/cpuset.h | 2 +- include/linux/sched.h | 7 +++++++ kernel/cpuset.c | 4 ++-- kernel/kthread.c | 4 ++-- kernel/sched.c | 19 ++++++++++++------- 5 files changed, 24 insertions(+), 12 deletions(-) diff --git a/include/linux/cpuset.h b/include/linux/cpuset.h index f20eb8f..e9eaec5 100644 --- a/include/linux/cpuset.h +++ b/include/linux/cpuset.h @@ -146,7 +146,7 @@ static inline void cpuset_cpus_allowed(struct task_struct *p, static inline int cpuset_cpus_allowed_fallback(struct task_struct *p) { - cpumask_copy(&p->cpus_allowed, cpu_possible_mask); + do_set_cpus_allowed(p, cpu_possible_mask); return cpumask_any(cpu_active_mask); } diff --git a/include/linux/sched.h b/include/linux/sched.h index dc88712..8da84b7 100644 --- a/include/linux/sched.h +++ b/include/linux/sched.h @@ -1841,9 +1841,16 @@ static inline void rcu_copy_process(struct task_struct *p) #endif #ifdef CONFIG_SMP +extern void do_set_cpus_allowed(struct task_struct *p, + const struct cpumask *new_mask); + extern int set_cpus_allowed_ptr(struct task_struct *p, const struct cpumask *new_mask); #else +static inline void do_set_cpus_allowed(struct task_struct *p, + const struct cpumask *new_mask) +{ +} static inline int set_cpus_allowed_ptr(struct task_struct *p, const struct cpumask *new_mask) { diff --git a/kernel/cpuset.c b/kernel/cpuset.c index 1ceeb04..9c9b754 100644 --- a/kernel/cpuset.c +++ b/kernel/cpuset.c @@ -2190,7 +2190,7 @@ int cpuset_cpus_allowed_fallback(struct task_struct *tsk) rcu_read_lock(); cs = task_cs(tsk); if (cs) - cpumask_copy(&tsk->cpus_allowed, cs->cpus_allowed); + do_set_cpus_allowed(tsk, cs->cpus_allowed); rcu_read_unlock(); /* @@ -2217,7 +2217,7 @@ int cpuset_cpus_allowed_fallback(struct task_struct *tsk) * Like above we can temporary set any mask and rely on * set_cpus_allowed_ptr() as synchronization point. */ - cpumask_copy(&tsk->cpus_allowed, cpu_possible_mask); + do_set_cpus_allowed(tsk, cpu_possible_mask); cpu = cpumask_any(cpu_active_mask); } diff --git a/kernel/kthread.c b/kernel/kthread.c index 3b34d27..4ba7ccc 100644 --- a/kernel/kthread.c +++ b/kernel/kthread.c @@ -202,8 +202,8 @@ void kthread_bind(struct task_struct *p, unsigned int cpu) return; } - p->cpus_allowed = cpumask_of_cpu(cpu); - p->rt.nr_cpus_allowed = 1; + /* It's safe because the task is inactive. */ + do_set_cpus_allowed(p, cpumask_of(cpu)); p->flags |= PF_THREAD_BOUND; } EXPORT_SYMBOL(kthread_bind); diff --git a/kernel/sched.c b/kernel/sched.c index a80ee91..cbb3a0e 100644 --- a/kernel/sched.c +++ b/kernel/sched.c @@ -5860,7 +5860,7 @@ void __cpuinit init_idle(struct task_struct *idle, int cpu) idle->state = TASK_RUNNING; idle->se.exec_start = sched_clock(); - cpumask_copy(&idle->cpus_allowed, cpumask_of(cpu)); + do_set_cpus_allowed(idle, cpumask_of(cpu)); /* * We're having a chicken and egg problem, even though we are * holding rq->lock, the cpu isn't yet set to this cpu so the @@ -5948,6 +5948,16 @@ static inline void sched_init_granularity(void) } #ifdef CONFIG_SMP +void do_set_cpus_allowed(struct task_struct *p, const struct cpumask *new_mask) +{ + if (p->sched_class && p->sched_class->set_cpus_allowed) + p->sched_class->set_cpus_allowed(p, new_mask); + else { + cpumask_copy(&p->cpus_allowed, new_mask); + p->rt.nr_cpus_allowed = cpumask_weight(new_mask); + } +} + /* * This is how migration works: * @@ -5993,12 +6003,7 @@ int set_cpus_allowed_ptr(struct task_struct *p, const struct cpumask *new_mask) goto out; } - if (p->sched_class->set_cpus_allowed) - p->sched_class->set_cpus_allowed(p, new_mask); - else { - cpumask_copy(&p->cpus_allowed, new_mask); - p->rt.nr_cpus_allowed = cpumask_weight(new_mask); - } + do_set_cpus_allowed(p, new_mask); /* Can the task run on the task's current CPU? If so, we're done */ if (cpumask_test_cpu(task_cpu(p), new_mask))