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>
Signed-off-by: David S. Miller <davem@davemloft.net>
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 @@
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 @@
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;