Commit 81705ad1 authored Jan 29, 2009 by Herbert Xu Committed by David S. Miller Jan 29, 2009

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>

parent 86911732

net/core/skbuff.c

+5 −3

Original line number	Diff line number	Diff line
		@@ -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 -=

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