1 files changed, 20 insertions, 8 deletions

diff --git a/kernel/workqueue.c b/kernel/workqueue.c
index 042d221d33cc..fbc6576a83c3 100644
--- a/kernel/workqueue.c
+++ b/kernel/workqueue.c
@@ -739,8 +739,10 @@ void wq_worker_waking_up(struct task_struct *task, unsigned int cpu)
 {
 	struct worker *worker = kthread_data(task);
 
-	if (!(worker->flags & WORKER_NOT_RUNNING))
+	if (!(worker->flags & WORKER_NOT_RUNNING)) {
+		WARN_ON_ONCE(worker->pool->gcwq->cpu != cpu);
 		atomic_inc(get_pool_nr_running(worker->pool));
+	}
 }
 
 /**
@@ -1361,8 +1363,19 @@ static void __queue_delayed_work(int cpu, struct workqueue_struct *wq,
 
 	WARN_ON_ONCE(timer->function != delayed_work_timer_fn ||
 		     timer->data != (unsigned long)dwork);
-	BUG_ON(timer_pending(timer));
-	BUG_ON(!list_empty(&work->entry));
+	WARN_ON_ONCE(timer_pending(timer));
+	WARN_ON_ONCE(!list_empty(&work->entry));
+
+	/*
+	 * If @delay is 0, queue @dwork->work immediately.  This is for
+	 * both optimization and correctness.  The earliest @timer can
+	 * expire is on the closest next tick and delayed_work users depend
+	 * on that there's no such delay when @delay is 0.
+	 */
+	if (!delay) {
+		__queue_work(cpu, wq, &dwork->work);
+		return;
+	}
 
 	timer_stats_timer_set_start_info(&dwork->timer);
 
@@ -1417,9 +1430,6 @@ bool queue_delayed_work_on(int cpu, struct workqueue_struct *wq,
 	bool ret = false;
 	unsigned long flags;
 
-	if (!delay)
-		return queue_work_on(cpu, wq, &dwork->work);
-
 	/* read the comment in __queue_work() */
 	local_irq_save(flags);
 
@@ -2407,8 +2417,10 @@ static int rescuer_thread(void *__wq)
 repeat:
 	set_current_state(TASK_INTERRUPTIBLE);
 
-	if (kthread_should_stop())
+	if (kthread_should_stop()) {
+		__set_current_state(TASK_RUNNING);
 		return 0;
+	}
 
 	/*
 	 * See whether any cpu is asking for help.  Unbounded
@@ -3475,7 +3487,7 @@ unsigned int work_busy(struct work_struct *work)
 	unsigned int ret = 0;
 
 	if (!gcwq)
-		return false;
+		return 0;
 
 	spin_lock_irqsave(&gcwq->lock, flags);