gro: Optimise Ethernet header comparison

This patch optimises the Ethernet header comparison to use 2-byte
and 4-byte xors instead of memcmp.  In order to facilitate this,
the actual comparison is now carried out by the callers of the
shared dev_gro_receive function.

This has a significant impact when receiving 1500B packets through
10GbE.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Herbert Xu 2009-02-08 18:00:37 +00:00 committed by David S. Miller
parent 4ae5544f9a
commit aa4b9f533e
4 changed files with 33 additions and 22 deletions

View file

@ -1117,6 +1117,13 @@ static inline void skb_gro_reset_offset(struct sk_buff *skb)
NAPI_GRO_CB(skb)->data_offset = 0;
}
static inline void *skb_gro_mac_header(struct sk_buff *skb)
{
return skb_mac_header(skb) < skb->data ? skb_mac_header(skb) :
page_address(skb_shinfo(skb)->frags[0].page) +
skb_shinfo(skb)->frags[0].page_offset;
}
static inline int dev_hard_header(struct sk_buff *skb, struct net_device *dev,
unsigned short type,
const void *daddr, const void *saddr,