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>
diff --git a/net/ipv4/route.c b/net/ipv4/route.c
index e4ba974..21ad369 100644
--- a/net/ipv4/route.c
+++ b/net/ipv4/route.c
@@ -1587,11 +1587,14 @@
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;
}