gro: Open-code memcpy in napi_fraginfo_skb

This patch optimises napi_fraginfo_skb to only copy the bits
necessary.  We also open-code the memcpy so that the alignment
information is always available to gcc.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 9 insertions, 1 deletions

diff --git a/net/core/dev.c b/net/core/dev.c
index df406dcf7482..ec5be1c7f2f1 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -2533,6 +2533,8 @@ struct sk_buff *napi_fraginfo_skb(struct napi_struct *napi,
         struct net_device *dev = napi->dev;
         struct sk_buff *skb = napi->skb;
         struct ethhdr *eth;
+        skb_frag_t *frag;
+        int i;
 
         napi->skb = NULL;
 
@@ -2545,8 +2547,14 @@ struct sk_buff *napi_fraginfo_skb(struct napi_struct *napi,
         }
 
         BUG_ON(info->nr_frags > MAX_SKB_FRAGS);
+        frag = &info->frags[info->nr_frags - 1];
+
+        for (i = skb_shinfo(skb)->nr_frags; i < info->nr_frags; i++) {
+                skb_fill_page_desc(skb, i, frag->page, frag->page_offset,
+                                   frag->size);
+                frag++;
+        }
         skb_shinfo(skb)->nr_frags = info->nr_frags;
-        memcpy(skb_shinfo(skb)->frags, info->frags, sizeof(info->frags));
 
         skb->data_len = info->len;
         skb->len += info->len;