---

yaml
---
r: 247969
b: refs/heads/master
c: 3137663
h: refs/heads/master
i:
  247967: 64d4f17
v: v3

[refs]

@@ -1,2 +1,2 @@
 ---
-refs/heads/master: 6df427fe8c481d3be437cbe8bd366bdac82b73c4
+refs/heads/master: 3137663dfb43bb3e3174e9da81db0c05f395fc1b

trunk/net/sched/sch_generic.c

@@ -815,9 +815,17 @@ static bool some_qdisc_is_busy(struct net_device *dev)
 	return false;
 }
 
+/**
+ * 	dev_deactivate_many - deactivate transmissions on several devices
+ * 	@head: list of devices to deactivate
+ *
+ *	This function returns only when all outstanding transmissions
+ *	have completed, unless all devices are in dismantle phase.
+ */
 void dev_deactivate_many(struct list_head *head)
 {
 	struct net_device *dev;
+	bool sync_needed = false;
 
 	list_for_each_entry(dev, head, unreg_list) {
 		netdev_for_each_tx_queue(dev, dev_deactivate_queue,
@@ -827,10 +835,15 @@ void dev_deactivate_many(struct list_head *head)
 					     &noop_qdisc);
 
 		dev_watchdog_down(dev);
+		sync_needed |= !dev->dismantle;
 	}
 
-	/* Wait for outstanding qdisc-less dev_queue_xmit calls. */
-	synchronize_rcu();
+	/* Wait for outstanding qdisc-less dev_queue_xmit calls.
+	 * This is avoided if all devices are in dismantle phase :
+	 * Caller will call synchronize_net() for us
+	 */
+	if (sync_needed)
+		synchronize_net();
 
 	/* Wait for outstanding qdisc_run calls. */
 	list_for_each_entry(dev, head, unreg_list)