[IPV4]: Avoid common branch mispredictions in ip_rcv_finish()
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 48e4ddc..7e78095 100644
--- a/net/ipv4/ip_input.c
+++ b/net/ipv4/ip_input.c
@@ -333,16 +333,16 @@
static inline int ip_rcv_finish(struct sk_buff *skb)
{
- struct net_device *dev = skb->dev;
struct iphdr *iph = skb->nh.iph;
- int err;
/*
* Initialise the virtual path cache for the packet. It describes
* how the packet travels inside Linux networking.
*/
- if (skb->dst == NULL) {
- if ((err = ip_route_input(skb, iph->daddr, iph->saddr, iph->tos, dev))) {
+ if (likely(skb->dst == NULL)) {
+ int err = ip_route_input(skb, iph->daddr, iph->saddr, iph->tos,
+ skb->dev);
+ if (unlikely(err)) {
if (err == -EHOSTUNREACH)
IP_INC_STATS_BH(IPSTATS_MIB_INADDRERRORS);
goto drop;
@@ -350,7 +350,7 @@
}
#ifdef CONFIG_NET_CLS_ROUTE
- if (skb->dst->tclassid) {
+ if (unlikely(skb->dst->tclassid)) {
struct ip_rt_acct *st = ip_rt_acct + 256*smp_processor_id();
u32 idx = skb->dst->tclassid;
st[idx&0xFF].o_packets++;