gro: Store shinfo in local variable in skb_gro_receive

This patch stores the two shinfo pointers in local variables
because they're used over and over again in skb_gro_receive.
Signed-off-by: NHerbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

net/core/skbuff.c

@@ -2664,6 +2664,8 @@ int skb_gro_receive(struct sk_buff **head, struct sk_buff *skb)
 {
 	struct sk_buff *p = *head;
 	struct sk_buff *nskb;
+	struct skb_shared_info *skbinfo = skb_shinfo(skb);
+	struct skb_shared_info *pinfo = skb_shinfo(p);
 	unsigned int headroom;
 	unsigned int len = skb_gro_len(skb);
 	unsigned int offset = skb_gro_offset(skb);
@@ -2672,24 +2674,24 @@ int skb_gro_receive(struct sk_buff **head, struct sk_buff *skb)
 	if (p->len + len >= 65536)
 		return -E2BIG;
 
-	if (skb_shinfo(p)->frag_list)
+	if (pinfo->frag_list)
 		goto merge;
 	else if (headlen <= offset) {
 		skb_frag_t *frag;
 		skb_frag_t *frag2;
-		int i = skb_shinfo(skb)->nr_frags;
-		int nr_frags = skb_shinfo(p)->nr_frags + i;
+		int i = skbinfo->nr_frags;
+		int nr_frags = pinfo->nr_frags + i;
 
 		offset -= headlen;
 
 		if (nr_frags > MAX_SKB_FRAGS)
 			return -E2BIG;
 
-		skb_shinfo(p)->nr_frags = nr_frags;
-		skb_shinfo(skb)->nr_frags = 0;
+		pinfo->nr_frags = nr_frags;
+		skbinfo->nr_frags = 0;
 
-		frag = skb_shinfo(p)->frags + nr_frags;
-		frag2 = skb_shinfo(skb)->frags + i;
+		frag = pinfo->frags + nr_frags;
+		frag2 = skbinfo->frags + i;
 		do {
 			*--frag = *--frag2;
 		} while (--i);
@@ -2726,7 +2728,7 @@ int skb_gro_receive(struct sk_buff **head, struct sk_buff *skb)
 
 	*NAPI_GRO_CB(nskb) = *NAPI_GRO_CB(p);
 	skb_shinfo(nskb)->frag_list = p;
-	skb_shinfo(nskb)->gso_size = skb_shinfo(p)->gso_size;
+	skb_shinfo(nskb)->gso_size = pinfo->gso_size;
 	skb_header_release(p);
 	nskb->prev = p;
 
@@ -2742,8 +2744,8 @@ int skb_gro_receive(struct sk_buff **head, struct sk_buff *skb)
 
 merge:
 	if (offset > headlen) {
-		skb_shinfo(skb)->frags[0].page_offset += offset - headlen;
-		skb_shinfo(skb)->frags[0].size -= offset - headlen;
+		skbinfo->frags[0].page_offset += offset - headlen;
+		skbinfo->frags[0].size -= offset - headlen;
 		offset = headlen;
 	}