rtnetlink: speedup rtnl_dump_ifinfo()
When handling large number of netdevice, rtnl_dump_ifinfo()
is very slow because it has O(N^2) complexity.
Instead of scanning one single list, we can use the 256 sub lists
of the dev_index hash table.
This considerably speedups "ip link" operations
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/include/net/net_namespace.h b/include/net/net_namespace.h
index 6994101..0addd45 100644
--- a/include/net/net_namespace.h
+++ b/include/net/net_namespace.h
@@ -28,6 +28,10 @@
struct net_generic;
struct sock;
+
+#define NETDEV_HASHBITS 8
+#define NETDEV_HASHENTRIES (1 << NETDEV_HASHBITS)
+
struct net {
atomic_t count; /* To decided when the network
* namespace should be freed.