1 files changed, 30 insertions, 37 deletions

diff --git a/kernel/workqueue.c b/kernel/workqueue.c
index 42fa9ad0a810..94eadf426eb3 100644
--- a/kernel/workqueue.c
+++ b/kernel/workqueue.c
@@ -137,6 +137,7 @@ struct worker {
 	unsigned int		flags;		/* X: flags */
 	int			id;		/* I: worker id */
 	struct work_struct	rebind_work;	/* L: rebind worker to cpu */
+	int			sleeping;	/* None */
 };
 
 /*
@@ -658,66 +659,58 @@ static void wake_up_worker(struct global_cwq *gcwq)
 }
 
 /**
- * wq_worker_waking_up - a worker is waking up
- * @task: task waking up
- * @cpu: CPU @task is waking up to
+ * wq_worker_running - a worker is running again
+ * @task: task returning from sleep
  *
- * This function is called during try_to_wake_up() when a worker is
- * being awoken.
- *
- * CONTEXT:
- * spin_lock_irq(rq->lock)
+ * This function is called when a worker returns from schedule()
  */
-void wq_worker_waking_up(struct task_struct *task, unsigned int cpu)
+void wq_worker_running(struct task_struct *task)
 {
 	struct worker *worker = kthread_data(task);
 
+	if (!worker->sleeping)
+		return;
 	if (!(worker->flags & WORKER_NOT_RUNNING))
-		atomic_inc(get_gcwq_nr_running(cpu));
+		atomic_inc(get_gcwq_nr_running(smp_processor_id()));
+	worker->sleeping = 0;
 }
 
 /**
  * wq_worker_sleeping - a worker is going to sleep
  * @task: task going to sleep
- * @cpu: CPU in question, must be the current CPU number
- *
- * This function is called during schedule() when a busy worker is
- * going to sleep.  Worker on the same cpu can be woken up by
- * returning pointer to its task.
- *
- * CONTEXT:
- * spin_lock_irq(rq->lock)
  *
- * RETURNS:
- * Worker task on @cpu to wake up, %NULL if none.
+ * This function is called from schedule() when a busy worker is
+ * going to sleep.
  */
-struct task_struct *wq_worker_sleeping(struct task_struct *task,
-				       unsigned int cpu)
+void wq_worker_sleeping(struct task_struct *task)
 {
-	struct worker *worker = kthread_data(task), *to_wakeup = NULL;
-	struct global_cwq *gcwq = get_gcwq(cpu);
-	atomic_t *nr_running = get_gcwq_nr_running(cpu);
+	struct worker *worker = kthread_data(task);
+	struct global_cwq *gcwq;
+	int cpu;
 
 	if (worker->flags & WORKER_NOT_RUNNING)
-		return NULL;
+		return;
+
+	if (WARN_ON_ONCE(worker->sleeping))
+		return;
 
-	/* this can only happen on the local cpu */
-	BUG_ON(cpu != raw_smp_processor_id());
+	worker->sleeping = 1;
 
+	cpu = smp_processor_id();
+	gcwq = get_gcwq(cpu);
+	spin_lock_irq(&gcwq->lock);
 	/*
 	 * The counterpart of the following dec_and_test, implied mb,
 	 * worklist not empty test sequence is in insert_work().
 	 * Please read comment there.
-	 *
-	 * NOT_RUNNING is clear.  This means that trustee is not in
-	 * charge and we're running on the local cpu w/ rq lock held
-	 * and preemption disabled, which in turn means that none else
-	 * could be manipulating idle_list, so dereferencing idle_list
-	 * without gcwq lock is safe.
 	 */
-	if (atomic_dec_and_test(nr_running) && !list_empty(&gcwq->worklist))
-		to_wakeup = first_worker(gcwq);
-	return to_wakeup ? to_wakeup->task : NULL;
+	if (atomic_dec_and_test(get_gcwq_nr_running(cpu)) &&
+	    !list_empty(&gcwq->worklist)) {
+		worker = first_worker(gcwq);
+		if (worker)
+			wake_up_process(worker->task);
+	}
+	spin_unlock_irq(&gcwq->lock);
 }
 
 /**