ipv4: Introduce IN_DEV_NET_ROUTE_LOCALNET

performance profiles show a high cost in the IN_DEV_ROUTE_LOCALNET()
call done in ip_route_input_slow(), because of multiple dereferences,
even if cache lines are clean and available in cpu caches.

Since we already have the 'net' pointer, introduce
IN_DEV_NET_ROUTE_LOCALNET() macro avoiding two dereferences
(dev_net(in_dev->dev))

Also change the tests to use IN_DEV_NET_ROUTE_LOCALNET() only if saddr
or/and daddr are loopback addresse.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Eric Dumazet
2012-08-03 21:27:25 +00:00
committed by David S. Miller
parent 40384999d1
commit 9eb43e7653
2 changed files with 16 additions and 6 deletions

View File

@@ -1587,11 +1587,14 @@ static int ip_route_input_slow(struct sk_buff *skb, __be32 daddr, __be32 saddr,
if (ipv4_is_zeronet(daddr))
goto martian_destination;
if (likely(!IN_DEV_ROUTE_LOCALNET(in_dev))) {
if (ipv4_is_loopback(daddr))
/* Following code try to avoid calling IN_DEV_NET_ROUTE_LOCALNET(),
* and call it once if daddr or/and saddr are loopback addresses
*/
if (ipv4_is_loopback(daddr)) {
if (!IN_DEV_NET_ROUTE_LOCALNET(in_dev, net))
goto martian_destination;
if (ipv4_is_loopback(saddr))
} else if (ipv4_is_loopback(saddr)) {
if (!IN_DEV_NET_ROUTE_LOCALNET(in_dev, net))
goto martian_source;
}