workqueue: introduce cwq_set_max_active() helper for thaw_workqueues()

Using a helper instead of open code makes thaw_workqueues() clearer.
The helper will also be used by the next patch.

tj: Slight update to comment and description.

Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com>
Signed-off-by: Tejun Heo <tj@kernel.org>

kernel/workqueue.c

@@ -3366,6 +3366,26 @@ void destroy_workqueue(struct workqueue_struct *wq)
 }
 EXPORT_SYMBOL_GPL(destroy_workqueue);
 
+/**
+ * cwq_set_max_active - adjust max_active of a cwq
+ * @cwq: target cpu_workqueue_struct
+ * @max_active: new max_active value.
+ *
+ * Set @cwq->max_active to @max_active and activate delayed works if
+ * increased.
+ *
+ * CONTEXT:
+ * spin_lock_irq(gcwq->lock).
+ */
+static void cwq_set_max_active(struct cpu_workqueue_struct *cwq, int max_active)
+{
+	cwq->max_active = max_active;
+
+	while (!list_empty(&cwq->delayed_works) &&
+	       cwq->nr_active < cwq->max_active)
+		cwq_activate_first_delayed(cwq);
+}
+
 /**
  * workqueue_set_max_active - adjust max_active of a workqueue
  * @wq: target workqueue
@@ -3792,11 +3812,7 @@ void thaw_workqueues(void)
 				continue;
 
 			/* restore max_active and repopulate worklist */
-			cwq->max_active = wq->saved_max_active;
-
-			while (!list_empty(&cwq->delayed_works) &&
-			       cwq->nr_active < cwq->max_active)
-				cwq_activate_first_delayed(cwq);
+			cwq_set_max_active(cwq, wq->saved_max_active);
 		}
 
 		for_each_worker_pool(pool, gcwq)