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sched: Avoid going ahead if ->cpus_allowed is not changed 

If cpumask_equal(&p->cpus_allowed, new_mask) is true, seems
there is no reason to prevent set_cpus_allowed_ptr() return
directly.

Signed-off-by: Yong Zhang <yong.zhang0@gmail.com>
Acked-by: Hillf Danton <dhillf@gmail.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/20110509140705.GA2219@zhy
Signed-off-by: Ingo Molnar <mingo@elte.hu>
hifive-unleashed-5.1
Yong Zhang 2011-05-09 22:07:05 +08:00 committed by Ingo Molnar
parent 61eadef6a9
commit db44fc017d
1 changed files with 4 additions and 2 deletions
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6
kernel/sched.c
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@ -5946,13 +5946,15 @@ int set_cpus_allowed_ptr(struct task_struct *p, const struct cpumask *new_mask)
rq = task_rq_lock(p, &flags);
if (cpumask_equal(&p->cpus_allowed, new_mask))
goto out;
if (!cpumask_intersects(new_mask, cpu_active_mask)) {
ret = -EINVAL;
goto out;
}
if (unlikely((p->flags & PF_THREAD_BOUND) && p != current &&
!cpumask_equal(&p->cpus_allowed, new_mask))) {
if (unlikely((p->flags & PF_THREAD_BOUND) && p != current)) {
ret = -EINVAL;
goto out;
}