[NET]: Optimize pskb_trim_rcsum()

Since packets almost never contain extra garbage at the end, it is
worthwhile to optimize for that case.

Signed-off-by: Stephen Hemminger <shemminger@osdl.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h
index da7da9c..2741c0c 100644 (file)
--- a/include/linux/skbuff.h
+++ b/include/linux/skbuff.h
@@ -1167,7 +1167,7 @@ static inline void skb_postpull_rcsum(struct sk_buff *skb,
 
 static inline int pskb_trim_rcsum(struct sk_buff *skb, unsigned int len)
 {
-       if (len >= skb->len)
+       if (likely(len >= skb->len))
                return 0;
        if (skb->ip_summed == CHECKSUM_HW)
                skb->ip_summed = CHECKSUM_NONE;