From: Lai Jiangshan <laijs@cn.fujitsu.com>
To: Tejun Heo <tj@kernel.org>, linux-kernel@vger.kernel.org
Cc: Lai Jiangshan <laijs@cn.fujitsu.com>
Subject: [PATCH 10/21] workqueue: use rcu_read_lock_sched() instead for accessing pwq in RCU
Date: Wed, 20 Mar 2013 03:28:10 +0800 [thread overview]
Message-ID: <1363721306-2030-11-git-send-email-laijs@cn.fujitsu.com> (raw)
In-Reply-To: <1363721306-2030-1-git-send-email-laijs@cn.fujitsu.com>
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>
---
kernel/workqueue.c | 10 +++++-----
1 files changed, 5 insertions(+), 5 deletions(-)
diff --git a/kernel/workqueue.c b/kernel/workqueue.c
index ad190cd..469269e 100644
--- a/kernel/workqueue.c
+++ b/kernel/workqueue.c
@@ -3967,7 +3967,7 @@ 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);
@@ -3975,7 +3975,7 @@ 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;
}
@@ -4361,16 +4361,16 @@ 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(&wqs_mutex);
--
1.7.7.6
next prev parent reply other threads:[~2013-03-19 19:32 UTC|newest]
Thread overview: 39+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-03-19 19:28 [PATCH 00/21] workqueue: cleanups and better locking for recent changes Lai Jiangshan
2013-03-19 19:28 ` [PATCH 01/21] workqueue: add missing POOL_FREEZING Lai Jiangshan
2013-03-20 17:18 ` Tejun Heo
2013-03-20 17:24 ` Tejun Heo
2013-03-19 19:28 ` [PATCH 02/21] workqueue: don't free pool->worker_idr by RCU Lai Jiangshan
2013-03-20 17:29 ` Tejun Heo
2013-03-19 19:28 ` [PATCH 03/21] workqueue: simplify current_is_workqueue_rescuer() Lai Jiangshan
2013-03-20 17:33 ` Tejun Heo
2013-03-19 19:28 ` [PATCH 04/21] workqueue: swap the two branches in pwq_adjust_max_active() to get better readability Lai Jiangshan
2013-03-20 17:39 ` Tejun Heo
2013-03-19 19:28 ` [PATCH 05/21] workqueue: kick workers in pwq_adjust_max_active() Lai Jiangshan
2013-03-20 17:56 ` [PATCH] workqueue: kick a worker " Tejun Heo
2013-03-19 19:28 ` [PATCH 06/21] workqueue: separate out pools locking into pools_mutex Lai Jiangshan
2013-03-20 17:58 ` Tejun Heo
2013-03-19 19:28 ` [PATCH 07/21] workqueue: rename wq_mutex to wqs_mutex Lai Jiangshan
2013-03-19 19:28 ` [PATCH 08/21] workqueue: rename wq->flush_mutex to wq->mutex Lai Jiangshan
2013-03-19 19:28 ` [PATCH 09/21] workqueue: use wq->mutex to protects ->nr_drainers and __WQ_DRAINING Lai Jiangshan
2013-03-19 19:28 ` Lai Jiangshan [this message]
2013-03-20 18:01 ` [PATCH 10/21] workqueue: use rcu_read_lock_sched() instead for accessing pwq in RCU Tejun Heo
2013-03-19 19:28 ` [PATCH 11/21] workqueue: also allowed wq->mutex protect for_each_pwq() Lai Jiangshan
2013-03-19 19:28 ` [PATCH 12/21] workqueue: use wq->mutex to protect saved_max_active Lai Jiangshan
2013-03-19 19:28 ` [PATCH 13/21] workqueue: remove unused pwq_lock Lai Jiangshan
2013-03-19 19:28 ` [PATCH 14/21] workqueue: add wq->freezing and remove POOL_FREEZING Lai Jiangshan
2013-03-19 19:28 ` [PATCH 15/21] workqueue: remove worker_maybe_bind_and_lock() Lai Jiangshan
2013-03-20 18:10 ` Tejun Heo
2013-03-21 11:03 ` Lai Jiangshan
2013-03-21 17:41 ` Tejun Heo
2013-03-19 19:28 ` [PATCH 16/21] workqueue: rename rebind_workers() to associate_cpu_pool() Lai Jiangshan
2013-03-19 19:28 ` [PATCH 17/21] workqueue: simplify workqueue_cpu_up_callback(CPU_ONLINE) Lai Jiangshan
2013-03-20 18:16 ` Tejun Heo
2013-03-19 19:28 ` [PATCH 18/21] workqueue: read POOL_DISASSOCIATED bit under pool->lock Lai Jiangshan
2013-03-20 18:19 ` Tejun Heo
2013-03-19 19:28 ` [PATCH 19/21] workqueue: remove @p_last_pwq from init_and_link_pwq() Lai Jiangshan
2013-03-19 19:28 ` [PATCH 20/21] workqueue: modify wq->freezing only when freezable Lai Jiangshan
2013-03-19 19:28 ` [PATCH 21/21] workqueue: avoid false negative in assert_manager_or_pool_lock() Lai Jiangshan
2013-03-20 18:22 ` Tejun Heo
2013-03-20 16:38 ` [PATCH 00/21] workqueue: cleanups and better locking for recent changes Lai Jiangshan
2013-03-20 16:40 ` Tejun Heo
2013-03-20 18:30 ` Tejun Heo
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