ipip: Optimize multiple unregistration

Speedup module unloading by factorizing synchronize_rcu() calls

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

diff --git a/net/ipv4/ipip.c b/net/ipv4/ipip.c
index 3bd6998..a2ca53d 100644 (file)
--- a/net/ipv4/ipip.c
+++ b/net/ipv4/ipip.c
@@ -754,16 +754,19 @@ static struct xfrm_tunnel ipip_handler = {
 static const char banner[] __initconst =
        KERN_INFO "IPv4 over IPv4 tunneling driver\n";
 
-static void ipip_destroy_tunnels(struct ipip_net *ipn)
+static void ipip_destroy_tunnels(struct ipip_net *ipn, struct list_head *head)
 {
        int prio;
 
        for (prio = 1; prio < 4; prio++) {
                int h;
                for (h = 0; h < HASH_SIZE; h++) {
-                       struct ip_tunnel *t;
-                       while ((t = ipn->tunnels[prio][h]) != NULL)
-                               unregister_netdevice(t->dev);
+                       struct ip_tunnel *t = ipn->tunnels[prio][h];
+
+                       while (t != NULL) {
+                               unregister_netdevice_queue(t->dev, head);
+                               t = t->next;
+                       }
                }
        }
 }
@@ -816,11 +819,13 @@ err_alloc:
 static void ipip_exit_net(struct net *net)
 {
        struct ipip_net *ipn;
+       LIST_HEAD(list);
 
        ipn = net_generic(net, ipip_net_id);
        rtnl_lock();
-       ipip_destroy_tunnels(ipn);
-       unregister_netdevice(ipn->fb_tunnel_dev);
+       ipip_destroy_tunnels(ipn, &list);
+       unregister_netdevice_queue(ipn->fb_tunnel_dev, &list);
+       unregister_netdevice_many(&list);
        rtnl_unlock();
        kfree(ipn);
 }