workqueue: Factor out pwq_is_empty()

[ Upstream commit afa87ce85379e2d93863fce595afdb5771a84004 ]

"!pwq->nr_active && list_empty(&pwq->inactive_works)" test is repeated
multiple times. Let's factor it out into pwq_is_empty().

Signed-off-by: Tejun Heo <tj@kernel.org>
Reviewed-by: Lai Jiangshan <jiangshanlai@gmail.com>
Stable-dep-of: 5797b1c18919 ("workqueue: Implement system-wide nr_active enforcement for unbound workqueues")
Signed-off-by: Sasha Levin <sashal@kernel.org>

kernel/workqueue.c

@@ -1450,6 +1450,11 @@ static void put_pwq_unlocked(struct pool_workqueue *pwq)
 	}
 }
 
+static bool pwq_is_empty(struct pool_workqueue *pwq)
+{
+	return !pwq->nr_active && list_empty(&pwq->inactive_works);
+}
+
 static void pwq_activate_inactive_work(struct work_struct *work)
 {
 	struct pool_workqueue *pwq = get_work_pwq(work);
@@ -3319,7 +3324,7 @@ void drain_workqueue(struct workqueue_struct *wq)
 		bool drained;
 
 		raw_spin_lock_irq(&pwq->pool->lock);
-		drained = !pwq->nr_active && list_empty(&pwq->inactive_works);
+		drained = pwq_is_empty(pwq);
 		raw_spin_unlock_irq(&pwq->pool->lock);
 
 		if (drained)
@@ -4779,7 +4784,7 @@ static bool pwq_busy(struct pool_workqueue *pwq)
 
 	if ((pwq != pwq->wq->dfl_pwq) && (pwq->refcnt > 1))
 		return true;
-	if (pwq->nr_active || !list_empty(&pwq->inactive_works))
+	if (!pwq_is_empty(pwq))
 		return true;
 
 	return false;
@@ -5217,7 +5222,7 @@ void show_one_workqueue(struct workqueue_struct *wq)
 	unsigned long flags;
 
 	for_each_pwq(pwq, wq) {
-		if (pwq->nr_active || !list_empty(&pwq->inactive_works)) {
+		if (!pwq_is_empty(pwq)) {
 			idle = false;
 			break;
 		}
@@ -5229,7 +5234,7 @@ void show_one_workqueue(struct workqueue_struct *wq)
 
 	for_each_pwq(pwq, wq) {
 		raw_spin_lock_irqsave(&pwq->pool->lock, flags);
-		if (pwq->nr_active || !list_empty(&pwq->inactive_works)) {
+		if (!pwq_is_empty(pwq)) {
 			/*
 			 * Defer printing to avoid deadlocks in console
 			 * drivers that queue work while holding locks