aboutsummaryrefslogtreecommitdiffstats
path: root/net
diff options
context:
space:
mode:
authorPavel Emelyanov <xemul@parallels.com>2012-08-08 17:53:19 -0400
committerDavid S. Miller <davem@davemloft.net>2012-08-09 19:18:07 -0400
commitaa79e66eee5d525e2fcbd2a5fcb87ae3dd4aa9e9 (patch)
treefd275880600683733adcb1d84477ea35a04dd901 /net
parente6f8f1a739b652c56e6f959d6714d92e05621e21 (diff)
net: Make ifindex generation per-net namespace
Strictly speaking this is only _really_ required for checkpoint-restore to make loopback device always have the same index. This change appears to be safe wrt "ifindex should be unique per-system" concept, as all the ifindex usage is either already made per net namespace of is explicitly limited with init_net only. There are two cool side effects of this. The first one -- ifindices of devices in container are always small, regardless of how many containers we've started (and re-started) so far. The second one is -- we can speed up the loopback ifidex access as shown in the next patch. v2: Place ifindex right after dev_base_seq : avoid two holes and use the same cache line, dirtied in list_netdevice()/unlist_netdevice() Signed-off-by: Pavel Emelyanov <xemul@parallels.com> Acked-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net')
-rw-r--r--net/core/dev.c4
1 files changed, 2 insertions, 2 deletions
diff --git a/net/core/dev.c b/net/core/dev.c
index 3ca300d85271..1f06df8d10a3 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -5221,12 +5221,12 @@ int dev_ioctl(struct net *net, unsigned int cmd, void __user *arg)
5221 */ 5221 */
5222static int dev_new_index(struct net *net) 5222static int dev_new_index(struct net *net)
5223{ 5223{
5224 static int ifindex; 5224 int ifindex = net->ifindex;
5225 for (;;) { 5225 for (;;) {
5226 if (++ifindex <= 0) 5226 if (++ifindex <= 0)
5227 ifindex = 1; 5227 ifindex = 1;
5228 if (!__dev_get_by_index(net, ifindex)) 5228 if (!__dev_get_by_index(net, ifindex))
5229 return ifindex; 5229 return net->ifindex = ifindex;
5230 } 5230 }
5231} 5231}
5232 5232