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 7/9 V3] workqueue: explicit way to wait for idles workers to finish
Date: Thu, 30 Aug 2012 00:51:58 +0800 [thread overview]
Message-ID: <1346259120-6216-8-git-send-email-laijs@cn.fujitsu.com> (raw)
In-Reply-To: <1346259120-6216-1-git-send-email-laijs@cn.fujitsu.com>
busy_worker_rebind_fn() can't return until all idle workers are rebound.
This order is ensured by rebind_workers() currently.
We use mutex_lock(&worker->pool->manager_mutex) to wait for all idle workers
to be rebound. this is an explicit way and it will ease the pain of
the rebind_workers().
The sleeping mutex_lock(&worker->pool->manager_mutex) must be put in the top of
busy_worker_rebind_fn(), because this busy worker thread can sleep
before the WORKER_REBIND is cleared, but can't sleep after
the WORKER_REBIND cleared.
It adds a small overhead to the unlikely path.
Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com>
---
kernel/workqueue.c | 8 +++++++-
1 files changed, 7 insertions(+), 1 deletions(-)
diff --git a/kernel/workqueue.c b/kernel/workqueue.c
index d88aa2e..719d6ec 100644
--- a/kernel/workqueue.c
+++ b/kernel/workqueue.c
@@ -1376,9 +1376,15 @@ static void busy_worker_rebind_fn(struct work_struct *work)
struct worker *worker = container_of(work, struct worker, rebind_work);
struct global_cwq *gcwq = worker->pool->gcwq;
+ /*
+ * Waiting all idle workers are rebound by competing on
+ * pool->manager_mutex.
+ */
+ mutex_lock(&worker->pool->manager_mutex);
+
if (worker_maybe_bind_and_lock(worker))
worker_clr_flags(worker, WORKER_REBIND);
-
+ non_manager_role_manager_mutex_unlock(worker->pool);
spin_unlock_irq(&gcwq->lock);
}
--
1.7.4.4
next prev parent reply other threads:[~2012-08-29 16:50 UTC|newest]
Thread overview: 18+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-08-29 16:51 [PATCH 0/9 V3] workqueue: fix and cleanup hotplug/rebind_workers() Lai Jiangshan
2012-08-29 16:51 ` [PATCH 1/9 V3] workqueue: ensure the wq_worker_sleeping() see the right flags Lai Jiangshan
2012-08-29 16:51 ` [PATCH 2/9 V3] workqueue: fix deadlock in rebind_workers() Lai Jiangshan
2012-08-29 16:51 ` [PATCH 3/9 V3] workqueue: add POOL_MANAGING_WORKERS Lai Jiangshan
2012-08-29 18:21 ` Tejun Heo
2012-08-30 2:38 ` Lai Jiangshan
2012-08-29 16:51 ` [PATCH 4/9 V3] workqueue: add non_manager_role_manager_mutex_unlock() Lai Jiangshan
2012-08-29 18:25 ` Tejun Heo
2012-08-30 9:16 ` Lai Jiangshan
2012-08-30 9:17 ` Tejun Heo
2012-08-31 1:08 ` Lai Jiangshan
2012-08-29 16:51 ` [PATCH 5/9 V3] workqueue: move rebind_hold to idle_rebind Lai Jiangshan
2012-08-29 16:51 ` [PATCH 6/9 V3] workqueue: simple clear WORKER_REBIND Lai Jiangshan
2012-08-29 16:51 ` Lai Jiangshan [this message]
2012-08-29 18:34 ` [PATCH 7/9 V3] workqueue: explicit way to wait for idles workers to finish Tejun Heo
2012-08-29 16:51 ` [PATCH 8/9 V3] workqueue: single pass rebind_workers Lai Jiangshan
2012-08-29 18:40 ` Tejun Heo
2012-08-29 16:52 ` [PATCH 9/9 V3] workqueue: merge the role of rebind_hold to idle_done Lai Jiangshan
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