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>

1 files changed, 22 insertions, 21 deletions

diff --git a/net/core/skbuff.c b/net/core/skbuff.c
index 512dc7dcbc32..d4fdc649112c 100644
--- 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);
 }
 
 /*