[IPV4]: Avoid common branch misprediction while checking csum in ip_rcv()

Signed-off-by: Thomas Graf <tgraf@suug.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/net/ipv4/ip_input.c b/net/ipv4/ip_input.c
index 322b082ede1ecaa58545ea34017d4873e9524c96..6a06e15694dc4e266a6b09d01965e24a6457c519 100644 (file)
--- a/net/ipv4/ip_input.c
+++ b/net/ipv4/ip_input.c
@@ -400,7 +400,7 @@ int ip_rcv(struct sk_buff *skb, struct net_device *dev, struct packet_type *pt,
 
        iph = skb->nh.iph;
 
-       if (ip_fast_csum((u8 *)iph, iph->ihl) != 0)
+       if (unlikely(ip_fast_csum((u8 *)iph, iph->ihl)))
                goto inhdr_error;
 
        len = ntohs(iph->tot_len);