From: Eric Dumazet <eric.dumazet@gmail.com>
Date: Thu, 18 Mar 2010 13:37:40 +0000 (+0000)
Subject: net: speedup netdev_set_master()
X-Git-Tag: v2.6.35-rc1~473^2~724
X-Git-Url: https://git.kernel.dk/?a=commitdiff_plain;h=283f2fe87e980d8af5ad8aa63751e7e3258ee05a;p=linux-block.git

net: speedup netdev_set_master()

We currently force a synchronize_net() in netdev_set_master()

This seems necessary only when a slave had a master and we dismantle it.

In the other case ("ifenslave bond0 ethO"), we dont need this long
delay.

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
---

diff --git a/net/core/dev.c b/net/core/dev.c
index fe2a754238a9..2d01f18f303a 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -3757,11 +3757,10 @@ int netdev_set_master(struct net_device *slave, struct net_device *master)
 
 	slave->master = master;
 
-	synchronize_net();
-
-	if (old)
+	if (old) {
+		synchronize_net();
 		dev_put(old);
-
+	}
 	if (master)
 		slave->flags |= IFF_SLAVE;
 	else