udp: avoid a cache miss on dequeue

[linux.git] / include / linux / skbuff.h

diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h
index 45a59c1e0cc7ae70f55499dea2ef93d6d82e757f..d66d4feaac867633af0162065e105caf8f4cb383 100644 (file)
--- a/include/linux/skbuff.h
+++ b/include/linux/skbuff.h
@@ -867,10 +867,25 @@ static inline unsigned int skb_napi_id(const struct sk_buff *skb)
 #endif
 }
 
+/* decrement the reference count and return true if we can free the skb */
+static inline bool skb_unref(struct sk_buff *skb)
+{
+       if (unlikely(!skb))
+               return false;
+       if (likely(atomic_read(&skb->users) == 1))
+               smp_rmb();
+       else if (likely(!atomic_dec_and_test(&skb->users)))
+               return false;
+
+       return true;
+}
+
+void skb_release_head_state(struct sk_buff *skb);
 void kfree_skb(struct sk_buff *skb);
 void kfree_skb_list(struct sk_buff *segs);
 void skb_tx_error(struct sk_buff *skb);
 void consume_skb(struct sk_buff *skb);
+void consume_stateless_skb(struct sk_buff *skb);
 void  __kfree_skb(struct sk_buff *skb);
 extern struct kmem_cache *skbuff_head_cache;
 
@@ -953,10 +968,10 @@ struct sk_buff *skb_realloc_headroom(struct sk_buff *skb,
                                     unsigned int headroom);
 struct sk_buff *skb_copy_expand(const struct sk_buff *skb, int newheadroom,
                                int newtailroom, gfp_t priority);
-int skb_to_sgvec_nomark(struct sk_buff *skb, struct scatterlist *sg,
-                       int offset, int len);
-int skb_to_sgvec(struct sk_buff *skb, struct scatterlist *sg, int offset,
-                int len);
+int __must_check skb_to_sgvec_nomark(struct sk_buff *skb, struct scatterlist *sg,
+                                    int offset, int len);
+int __must_check skb_to_sgvec(struct sk_buff *skb, struct scatterlist *sg,
+                             int offset, int len);
 int skb_cow_data(struct sk_buff *skb, int tailbits, struct sk_buff **trailer);
 int skb_pad(struct sk_buff *skb, int pad);
 #define dev_kfree_skb(a)       consume_skb(a)