gro: Do not merge paged packets into frag_list

gro: Do not merge paged packets into frag_list

Bigger is not always better :)

It was easy to continue to merged packets into frag_list after the
page array is full.  However, this turns out to be worse than LRO
because frag_list is a much less efficient form of storage than the
page array.  So we're better off stopping the merge and starting
a new entry with an empty page array.

In future we can optimise this further by doing frag_list merging
but making sure that we continue to fill in the page array.

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 2009-01-29 14:19:51 +00:00 committed by David S. Miller
parent 86911732d3
commit 81705ad1b2

View File

@ -2591,9 +2591,11 @@ int skb_gro_receive(struct sk_buff **head, struct sk_buff *skb)
if (skb_shinfo(p)->frag_list)
goto merge;
else if (skb_headlen(skb) <= skb_gro_offset(skb) &&
skb_shinfo(p)->nr_frags + skb_shinfo(skb)->nr_frags <=
MAX_SKB_FRAGS) {
else if (skb_headlen(skb) <= skb_gro_offset(skb)) {
if (skb_shinfo(p)->nr_frags + skb_shinfo(skb)->nr_frags >
MAX_SKB_FRAGS)
return -E2BIG;
skb_shinfo(skb)->frags[0].page_offset +=
skb_gro_offset(skb) - skb_headlen(skb);
skb_shinfo(skb)->frags[0].size -=