net: Use ip_route_input_noref() in input path

Use ip_route_input_noref() in ip fast path, to avoid two atomic ops per
incoming packet.

Note: loopback is excluded from this optimization in ip_rcv_finish()

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

1 files changed, 2 insertions, 2 deletions

diff --git a/net/ipv4/ip_input.c b/net/ipv4/ip_input.c
index af76de5f76de..d930dc5e4d85 100644
--- a/net/ipv4/ip_input.c
+++ b/net/ipv4/ip_input.c
@@ -331,8 +331,8 @@ static int ip_rcv_finish(struct sk_buff *skb)
          *      how the packet travels inside Linux networking.
          */
         if (skb_dst(skb) == NULL) {
-                int err = ip_route_input(skb, iph->daddr, iph->saddr, iph->tos,
-                                         skb->dev);
+                int err = ip_route_input_noref(skb, iph->daddr, iph->saddr,
+                                               iph->tos, skb->dev);
                 if (unlikely(err)) {
                         if (err == -EHOSTUNREACH)
                                 IP_INC_STATS_BH(dev_net(skb->dev),