diff options
author | KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> | 2011-05-19 10:08:58 +0400 |
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committer | Ingo Molnar <mingo@elte.hu> | 2011-05-28 19:02:57 +0400 |
commit | 1e1b6c511d1b23cb7c3b619d82fc7bd9f620565d (patch) | |
tree | c50e88412c8b42264177dc125f74a30f9c7a82d9 | |
parent | 1e876231785d82443a5ac8b6c660e9f51bc5dede (diff) | |
download | linux-1e1b6c511d1b23cb7c3b619d82fc7bd9f620565d.tar.xz |
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 <kosaki.motohiro@jp.fujitsu.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/4DD4B3FA.5060901@jp.fujitsu.com
Signed-off-by: Ingo Molnar <mingo@elte.hu>
-rw-r--r-- | include/linux/cpuset.h | 2 | ||||
-rw-r--r-- | include/linux/sched.h | 7 | ||||
-rw-r--r-- | kernel/cpuset.c | 4 | ||||
-rw-r--r-- | kernel/kthread.c | 4 | ||||
-rw-r--r-- | kernel/sched.c | 19 |
5 files changed, 24 insertions, 12 deletions
diff --git a/include/linux/cpuset.h b/include/linux/cpuset.h index f20eb8f16025..e9eaec522655 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 dc8871295a5a..8da84b7bc1b8 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 1ceeb049c827..9c9b7545c810 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 3b34d2732bce..4ba7cccb4994 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 a80ee911900e..cbb3a0eee58e 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)) |