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| author | Herbert Xu <herbert@gondor.apana.org.au> | 2009-05-26 18:50:32 +0000 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2009-05-27 03:26:04 -0700 |
| commit | 66e92fcf1ded5dd0da30d016ed47882eb183ec71 (patch) | |
| tree | be7f0fc2415ada8eb5030af53f3063375c381d47 | |
| parent | cb18978cbf454c236db5e4191a12ef71eef9b3a0 (diff) | |
| download | op-kernel-dev-66e92fcf1ded5dd0da30d016ed47882eb183ec71.zip op-kernel-dev-66e92fcf1ded5dd0da30d016ed47882eb183ec71.tar.gz | |
gro: Nasty optimisations for page frags in skb_gro_receive
This patch reverses the direction of the frags array copy in
skb_gro_receive in order simplify the loop conditional. It
also avoids touching the first element of the original frags
array.
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
| -rw-r--r-- | net/core/skbuff.c | 25 |
1 files changed, 15 insertions, 10 deletions
diff --git a/net/core/skbuff.c b/net/core/skbuff.c index 168e949..19afb18 100644 --- a/net/core/skbuff.c +++ b/net/core/skbuff.c @@ -2676,21 +2676,26 @@ int skb_gro_receive(struct sk_buff **head, struct sk_buff *skb) goto merge; else if (headlen <= offset) { skb_frag_t *frag; - int i; + skb_frag_t *frag2; + int i = skb_shinfo(skb)->nr_frags; + int nr_frags = skb_shinfo(p)->nr_frags + i; + + offset -= headlen; - if (skb_shinfo(p)->nr_frags + skb_shinfo(skb)->nr_frags > - MAX_SKB_FRAGS) + if (nr_frags > MAX_SKB_FRAGS) return -E2BIG; - skb_shinfo(skb)->frags[0].page_offset += offset - headlen; - skb_shinfo(skb)->frags[0].size -= offset - headlen; + skb_shinfo(p)->nr_frags = nr_frags; + skb_shinfo(skb)->nr_frags = 0; - frag = skb_shinfo(p)->frags + skb_shinfo(p)->nr_frags; - for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) - *frag++ = skb_shinfo(skb)->frags[i]; + frag = skb_shinfo(p)->frags + nr_frags; + frag2 = skb_shinfo(skb)->frags + i; + do { + *--frag = *--frag2; + } while (--i); - skb_shinfo(p)->nr_frags += skb_shinfo(skb)->nr_frags; - skb_shinfo(skb)->nr_frags = 0; + frag->page_offset += offset; + frag->size -= offset; skb->truesize -= skb->data_len; skb->len -= skb->data_len; |
