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* [PATCH] add likely/unlikely to pskb_may_pull
@ 2003-07-30 23:18 Stephen Hemminger
  2003-07-30 23:53 ` David S. Miller
  0 siblings, 1 reply; 2+ messages in thread
From: Stephen Hemminger @ 2003-07-30 23:18 UTC (permalink / raw)
  To: David S. Miller; +Cc: netdev

Code that deals with received headers needs to be robust and use pskb_may_pull in many
places, but except in the case of DOS attacks, the packets are always correctly formed
so optimize for that case.

diff -Nru a/include/linux/skbuff.h b/include/linux/skbuff.h
--- a/include/linux/skbuff.h	Wed Jul 30 15:50:31 2003
+++ b/include/linux/skbuff.h	Wed Jul 30 15:50:31 2003
@@ -904,9 +904,9 @@
 
 static inline int pskb_may_pull(struct sk_buff *skb, unsigned int len)
 {
-	if (len <= skb_headlen(skb))
+	if (likely(len <= skb_headlen(skb)))
 		return 1;
-	if (len > skb->len)
+	if (unlikely(len > skb->len))
 		return 0;
 	return __pskb_pull_tail(skb, len-skb_headlen(skb)) != NULL;
 }

^ permalink raw reply	[flat|nested] 2+ messages in thread

* Re: [PATCH] add likely/unlikely to pskb_may_pull
  2003-07-30 23:18 [PATCH] add likely/unlikely to pskb_may_pull Stephen Hemminger
@ 2003-07-30 23:53 ` David S. Miller
  0 siblings, 0 replies; 2+ messages in thread
From: David S. Miller @ 2003-07-30 23:53 UTC (permalink / raw)
  To: Stephen Hemminger; +Cc: netdev

On Wed, 30 Jul 2003 16:18:54 -0700
Stephen Hemminger <shemminger@osdl.org> wrote:

> Code that deals with received headers needs to be robust and use pskb_may_pull in many
> places, but except in the case of DOS attacks, the packets are always correctly formed
> so optimize for that case.

Applied, thanks Stephen.

^ permalink raw reply	[flat|nested] 2+ messages in thread

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2003-07-30 23:18 [PATCH] add likely/unlikely to pskb_may_pull Stephen Hemminger
2003-07-30 23:53 ` David S. Miller

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