gro: Open-code final pskb_may_pull

As we know the only packets which need the final pskb_may_pull
are completely non-linear, and have all the required bits in
frag0, we can perform a straight memcpy instead of going through
pskb_may_pull and doing skb_copy_bits.

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 18:50:31 +00:00 committed by David S. Miller
parent 1075f3f65d
commit cb18978cbf
1 changed files with 19 additions and 4 deletions

View File

@ -2452,10 +2452,25 @@ int dev_gro_receive(struct napi_struct *napi, struct sk_buff *skb)
ret = GRO_HELD; ret = GRO_HELD;
pull: pull:
if (unlikely(!pskb_may_pull(skb, skb_gro_offset(skb)))) { if (skb_headlen(skb) < skb_gro_offset(skb)) {
if (napi->gro_list == skb) int grow = skb_gro_offset(skb) - skb_headlen(skb);
napi->gro_list = skb->next;
ret = GRO_DROP; BUG_ON(skb->end - skb->tail < grow);
memcpy(skb_tail_pointer(skb), NAPI_GRO_CB(skb)->frag0, grow);
skb->tail += grow;
skb->data_len -= grow;
skb_shinfo(skb)->frags[0].page_offset += grow;
skb_shinfo(skb)->frags[0].size -= grow;
if (unlikely(!skb_shinfo(skb)->frags[0].size)) {
put_page(skb_shinfo(skb)->frags[0].page);
memmove(skb_shinfo(skb)->frags,
skb_shinfo(skb)->frags + 1,
--skb_shinfo(skb)->nr_frags);
}
} }
ok: ok: