[PATCH 11/11 V5] workqueue: remove manager_mutex

[Lai Jiangshan <laijs@cn.fujitsu.com>]

no one except manage_workers() use it. remove it.
manage_workers() will use ->manager instead.

Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com>
---
 kernel/workqueue.c |    7 ++-----
 1 files changed, 2 insertions(+), 5 deletions(-)

diff --git a/kernel/workqueue.c b/kernel/workqueue.c
index 5fb712a..eee3fad 100644
--- a/kernel/workqueue.c
+++ b/kernel/workqueue.c
@@ -163,7 +163,6 @@ struct worker_pool {
 	struct timer_list	mayday_timer;	/* L: SOS timer for workers */
 
 	struct worker		*manager;	/* L: manager worker */
-	struct mutex		manager_mutex;	/* mutex manager should hold */
 	struct ida		worker_ida;	/* L: for worker IDs */
 };
 
@@ -678,7 +677,7 @@ static bool need_to_manage_workers(struct worker_pool *pool)
 /* Do we have too many workers and should some go away? */
 static bool too_many_workers(struct worker_pool *pool)
 {
-	bool managing = mutex_is_locked(&pool->manager_mutex);
+	bool managing = !!pool->manager;
 	int nr_idle = pool->nr_idle + managing; /* manager is considered idle */
 	int nr_busy = pool->nr_workers - nr_idle;
 
@@ -2104,7 +2103,7 @@ static bool manage_workers(struct worker *worker)
 	struct worker_pool *pool = worker->pool;
 	bool ret = false;
 
-	if (!mutex_trylock(&pool->manager_mutex))
+	if (pool->manager)
 		return ret;
 
 	pool->manager = worker;
@@ -2118,7 +2117,6 @@ static bool manage_workers(struct worker *worker)
 	ret |= maybe_create_worker(pool);
 	ret |= maybe_rebind_manager(worker);
 
-	mutex_unlock(&pool->manager_mutex);
 	pool->manager = NULL;
 
 	return ret;
@@ -3785,7 +3783,6 @@ static int __init init_workqueues(void)
 				    (unsigned long)pool);
 
 			pool->manager = NULL;
-			mutex_init(&pool->manager_mutex);
 			ida_init(&pool->worker_ida);
 		}
 	}
-- 
1.7.4.4