[PATCH 2/4] net: add likely/unlikely to skb_header_pointer

[Stephen Hemminger <shemminger@vyatta.com>]

[-- Attachment #1: u32-header-likely.patch --]
[-- Type: text/plain, Size: 711 bytes --]

The expected case that should be optimized is that the offset is valid
and the data is available.

Signed-off-by: Stephen Hemminger <shemminger@vyatta.com>

--- a/include/linux/skbuff.h	2010-08-01 11:20:15.872942674 -0700
+++ b/include/linux/skbuff.h	2010-08-01 11:20:59.513693007 -0700
@@ -1853,13 +1853,13 @@ static inline void *skb_header_pointer(c
 {
 	int hlen = skb_headlen(skb);
 
-	if (hlen + offset < 0)
+	if (unlikely(hlen + offset < 0))
 		return NULL;
 
-	if (hlen - offset >= len)
+	if (likely(hlen - offset >= len))
 		return skb->data + offset;
 
-	if (skb_copy_bits(skb, offset, buffer, len) < 0)
+	if (unlikely(skb_copy_bits(skb, offset, buffer, len) < 0))
 		return NULL;
 
 	return buffer;