gro: Only use skb_gro_header for completely non-linear packets

Currently skb_gro_header is used for packets which put the hardware
header in skb->data with the rest in frags.  Since the drivers that
need this optimisation all provide completely non-linear packets,
we can gain extra optimisations by only performing the frag0
optimisation for completely non-linear packets.

In particular, we can simply test frag0 (instead of skb_headlen)
to see whether the optimisation is in force.

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
2009-05-26 18:50:23 +00:00
committed by David S. Miller
parent 67147ba99a
commit 78d3fd0b7d
2 changed files with 8 additions and 6 deletions

View File

@@ -2510,7 +2510,8 @@ void skb_gro_reset_offset(struct sk_buff *skb)
NAPI_GRO_CB(skb)->data_offset = 0;
NAPI_GRO_CB(skb)->frag0 = NULL;
if (!skb_headlen(skb) && !PageHighMem(skb_shinfo(skb)->frags[0].page))
if (skb->mac_header == skb->tail &&
!PageHighMem(skb_shinfo(skb)->frags[0].page))
NAPI_GRO_CB(skb)->frag0 =
page_address(skb_shinfo(skb)->frags[0].page) +
skb_shinfo(skb)->frags[0].page_offset;