[PATCH 1/14] gro: Open-code frags copy in skb_gro_receive
From: Herbert Xu <herbert@gondor.apana.org.au>
Date: 2009-05-27 05:08:02
Subsystem:
networking [general], the rest · Maintainers:
"David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Linus Torvalds
gro: Open-code frags copy in skb_gro_receive gcc does a poor job at generating code for the memcpy of the frags array in skb_gro_receive, which is the primary purpose of that function when merging frags. In particular, it can't utilise the alignment information of the source and destination. This patch open-codes the copy so we process words instead of bytes. Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> --- net/core/skbuff.c | 9 ++++++--- 1 file changed, 6 insertions(+), 3 deletions(-)
diff --git a/net/core/skbuff.c b/net/core/skbuff.c
index d429c41..c88426b 100644
--- a/net/core/skbuff.c
+++ b/net/core/skbuff.c@@ -2673,6 +2673,9 @@ 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_frag_t *frag; + int i; + if (skb_shinfo(p)->nr_frags + skb_shinfo(skb)->nr_frags > MAX_SKB_FRAGS) return -E2BIG;
@@ -2682,9 +2685,9 @@ int skb_gro_receive(struct sk_buff **head, struct sk_buff *skb) skb_shinfo(skb)->frags[0].size -= skb_gro_offset(skb) - skb_headlen(skb); - memcpy(skb_shinfo(p)->frags + skb_shinfo(p)->nr_frags, - skb_shinfo(skb)->frags, - skb_shinfo(skb)->nr_frags * sizeof(skb_frag_t)); + 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]; skb_shinfo(p)->nr_frags += skb_shinfo(skb)->nr_frags; skb_shinfo(skb)->nr_frags = 0;