1 files changed, 67 insertions, 23 deletions

diff --git a/net/core/link_watch.c b/net/core/link_watch.c
index 71a35da..b5f4579 100644
--- a/net/core/link_watch.c
+++ b/net/core/link_watch.c
@@ -77,11 +77,52 @@ static void rfc2863_policy(struct net_device *dev)
 }
 
 
-/* Must be called with the rtnl semaphore held */
-void linkwatch_run_queue(void)
+static int linkwatch_urgent_event(struct net_device *dev)
+{
+	return netif_running(dev) && netif_carrier_ok(dev) &&
+	       dev->qdisc != dev->qdisc_sleeping;
+}
+
+
+static void linkwatch_add_event(struct net_device *dev)
+{
+	unsigned long flags;
+
+	spin_lock_irqsave(&lweventlist_lock, flags);
+	dev->link_watch_next = lweventlist;
+	lweventlist = dev;
+	spin_unlock_irqrestore(&lweventlist_lock, flags);
+}
+
+
+static void linkwatch_schedule_work(unsigned long delay)
+{
+	if (test_and_set_bit(LW_RUNNING, &linkwatch_flags))
+		return;
+
+	/* If we wrap around we'll delay it by at most HZ. */
+	if (delay > HZ)
+		delay = 0;
+
+	schedule_delayed_work(&linkwatch_work, delay);
+}
+
+
+static void __linkwatch_run_queue(int urgent_only)
 {
 	struct net_device *next;
 
+	/*
+	 * Limit the number of linkwatch events to one
+	 * per second so that a runaway driver does not
+	 * cause a storm of messages on the netlink
+	 * socket.  This limit does not apply to up events
+	 * while the device qdisc is down.
+	 */
+	if (!urgent_only)
+		linkwatch_nextevent = jiffies + HZ;
+	clear_bit(LW_RUNNING, &linkwatch_flags);
+
 	spin_lock_irq(&lweventlist_lock);
 	next = lweventlist;
 	lweventlist = NULL;
@@ -92,6 +133,11 @@ void linkwatch_run_queue(void)
 
 		next = dev->link_watch_next;
 
+		if (urgent_only && !linkwatch_urgent_event(dev)) {
+			linkwatch_add_event(dev);
+			continue;
+		}
+
 		/*
 		 * Make sure the above read is complete since it can be
 		 * rewritten as soon as we clear the bit below.
@@ -116,21 +162,23 @@ void linkwatch_run_queue(void)
 
 		dev_put(dev);
 	}
+
+	if (lweventlist)
+		linkwatch_schedule_work(linkwatch_nextevent - jiffies);
 }
 
 
-static void linkwatch_event(struct work_struct *dummy)
+/* Must be called with the rtnl semaphore held */
+void linkwatch_run_queue(void)
 {
-	/* Limit the number of linkwatch events to one
-	 * per second so that a runaway driver does not
-	 * cause a storm of messages on the netlink
-	 * socket
-	 */
-	linkwatch_nextevent = jiffies + HZ;
-	clear_bit(LW_RUNNING, &linkwatch_flags);
+	__linkwatch_run_queue(0);
+}
+
 
+static void linkwatch_event(struct work_struct *dummy)
+{
 	rtnl_lock();
-	linkwatch_run_queue();
+	__linkwatch_run_queue(time_after(linkwatch_nextevent, jiffies));
 	rtnl_unlock();
 }
 
@@ -138,23 +186,19 @@ static void linkwatch_event(struct work_struct *dummy)
 void linkwatch_fire_event(struct net_device *dev)
 {
 	if (!test_and_set_bit(__LINK_STATE_LINKWATCH_PENDING, &dev->state)) {
-		unsigned long flags;
+		unsigned long delay;
 
 		dev_hold(dev);
 
-		spin_lock_irqsave(&lweventlist_lock, flags);
-		dev->link_watch_next = lweventlist;
-		lweventlist = dev;
-		spin_unlock_irqrestore(&lweventlist_lock, flags);
+		linkwatch_add_event(dev);
 
-		if (!test_and_set_bit(LW_RUNNING, &linkwatch_flags)) {
-			unsigned long delay = linkwatch_nextevent - jiffies;
+		delay = linkwatch_nextevent - jiffies;
 
-			/* If we wrap around we'll delay it by at most HZ. */
-			if (delay > HZ)
-				delay = 0;
-			schedule_delayed_work(&linkwatch_work, delay);
-		}
+		/* Minimise down-time: drop delay for up event. */
+		if (linkwatch_urgent_event(dev))
+			delay = 0;
+
+		linkwatch_schedule_work(delay);
 	}
 }