iv/linux
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

workqueue: use rcu_read_lock_sched() instead for accessing pwq in RCU

Browse Source 
rcu_read_lock_sched() is better than preempt_disable() if the code is
protected by RCU_SCHED.

Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
This commit is contained in:
Lai Jiangshan 2013-03-20 03:28:10 +08:00 committed by Tejun Heo
parent 951a078a52
commit 881094532e
1 changed files with 5 additions and 5 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

10
kernel/workqueue.c
View File

@ -3962,7 +3962,7 @@ bool workqueue_congested(int cpu, struct workqueue_struct *wq)
struct pool_workqueue *pwq;
bool ret;
preempt_disable();
rcu_read_lock_sched();
if (!(wq->flags & WQ_UNBOUND))
pwq = per_cpu_ptr(wq->cpu_pwqs, cpu);
@ -3970,7 +3970,7 @@ bool workqueue_congested(int cpu, struct workqueue_struct *wq)
pwq = first_pwq(wq);
ret = !list_empty(&pwq->delayed_works);
preempt_enable();
rcu_read_unlock_sched();
return ret;
}
@ -4354,16 +4354,16 @@ bool freeze_workqueues_busy(void)
* nr_active is monotonically decreasing. It's safe
* to peek without lock.
*/
preempt_disable();
rcu_read_lock_sched();
for_each_pwq(pwq, wq) {
WARN_ON_ONCE(pwq->nr_active < 0);
if (pwq->nr_active) {
busy = true;
preempt_enable();
rcu_read_unlock_sched();
goto out_unlock;
}
}
preempt_enable();
rcu_read_unlock_sched();
}
out_unlock:
mutex_unlock(&wq_mutex);