net : optimize skb_release_data()

Cache skb_shinfo(skb) in a variable to avoid computing it multiple
times.

Reorganize the tests to remove one indentation level.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/net/core/skbuff.c b/net/core/skbuff.c
index 512dc7dcbc32b9353ef62030c121f81f30a2a1d6..d4fdc649112c39c4e0f359174e17c2846b14d26e 100644 (file)
--- a/net/core/skbuff.c
+++ b/net/core/skbuff.c
@@ -491,32 +491,33 @@ static void skb_free_head(struct sk_buff *skb)
 
 static void skb_release_data(struct sk_buff *skb)
 {
-       if (!skb->cloned ||
-           !atomic_sub_return(skb->nohdr ? (1 << SKB_DATAREF_SHIFT) + 1 : 1,
-                              &skb_shinfo(skb)->dataref)) {
-               if (skb_shinfo(skb)->nr_frags) {
-                       int i;
-                       for (i = 0; i < skb_shinfo(skb)->nr_frags; i++)
-                               skb_frag_unref(skb, i);
-               }
+       struct skb_shared_info *shinfo = skb_shinfo(skb);
+       int i;
 
-               /*
-                * If skb buf is from userspace, we need to notify the caller
-                * the lower device DMA has done;
-                */
-               if (skb_shinfo(skb)->tx_flags & SKBTX_DEV_ZEROCOPY) {
-                       struct ubuf_info *uarg;
+       if (skb->cloned &&
+           atomic_sub_return(skb->nohdr ? (1 << SKB_DATAREF_SHIFT) + 1 : 1,
+                             &shinfo->dataref))
+               return;
 
-                       uarg = skb_shinfo(skb)->destructor_arg;
-                       if (uarg->callback)
-                               uarg->callback(uarg, true);
-               }
+       for (i = 0; i < shinfo->nr_frags; i++)
+               __skb_frag_unref(&shinfo->frags[i]);
 
-               if (skb_has_frag_list(skb))
-                       skb_drop_fraglist(skb);
+       /*
+        * If skb buf is from userspace, we need to notify the caller
+        * the lower device DMA has done;
+        */
+       if (shinfo->tx_flags & SKBTX_DEV_ZEROCOPY) {
+               struct ubuf_info *uarg;
 
-               skb_free_head(skb);
+               uarg = shinfo->destructor_arg;
+               if (uarg->callback)
+                       uarg->callback(uarg, true);
        }
+
+       if (shinfo->frag_list)
+               kfree_skb_list(shinfo->frag_list);
+
+       skb_free_head(skb);
 }
 
 /*