1 files changed, 18 insertions, 17 deletions

diff --git a/net/core/skbuff.c b/net/core/skbuff.c
index 92116df..7a338fb 100644
--- a/net/core/skbuff.c
+++ b/net/core/skbuff.c
@@ -265,7 +265,7 @@ struct sk_buff *__alloc_skb(unsigned int size, gfp_t gfp_mask,
 		skb->fclone = SKB_FCLONE_ORIG;
 		atomic_set(&fclones->fclone_ref, 1);
 
-		fclones->skb2.fclone = SKB_FCLONE_FREE;
+		fclones->skb2.fclone = SKB_FCLONE_CLONE;
 		fclones->skb2.pfmemalloc = pfmemalloc;
 	}
 out:
@@ -541,26 +541,27 @@ static void kfree_skbmem(struct sk_buff *skb)
 	switch (skb->fclone) {
 	case SKB_FCLONE_UNAVAILABLE:
 		kmem_cache_free(skbuff_head_cache, skb);
-		break;
+		return;
 
 	case SKB_FCLONE_ORIG:
 		fclones = container_of(skb, struct sk_buff_fclones, skb1);
-		if (atomic_dec_and_test(&fclones->fclone_ref))
-			kmem_cache_free(skbuff_fclone_cache, fclones);
-		break;
-
-	case SKB_FCLONE_CLONE:
-		fclones = container_of(skb, struct sk_buff_fclones, skb2);
 
-		/* The clone portion is available for
-		 * fast-cloning again.
+		/* We usually free the clone (TX completion) before original skb
+		 * This test would have no chance to be true for the clone,
+		 * while here, branch prediction will be good.
 		 */
-		skb->fclone = SKB_FCLONE_FREE;
+		if (atomic_read(&fclones->fclone_ref) == 1)
+			goto fastpath;
+		break;
 
-		if (atomic_dec_and_test(&fclones->fclone_ref))
-			kmem_cache_free(skbuff_fclone_cache, fclones);
+	default: /* SKB_FCLONE_CLONE */
+		fclones = container_of(skb, struct sk_buff_fclones, skb2);
 		break;
 	}
+	if (!atomic_dec_and_test(&fclones->fclone_ref))
+		return;
+fastpath:
+	kmem_cache_free(skbuff_fclone_cache, fclones);
 }
 
 static void skb_release_head_state(struct sk_buff *skb)
@@ -872,15 +873,15 @@ struct sk_buff *skb_clone(struct sk_buff *skb, gfp_t gfp_mask)
 	struct sk_buff_fclones *fclones = container_of(skb,
 						       struct sk_buff_fclones,
 						       skb1);
-	struct sk_buff *n = &fclones->skb2;
+	struct sk_buff *n;
 
 	if (skb_orphan_frags(skb, gfp_mask))
 		return NULL;
 
 	if (skb->fclone == SKB_FCLONE_ORIG &&
-	    n->fclone == SKB_FCLONE_FREE) {
-		n->fclone = SKB_FCLONE_CLONE;
-		atomic_inc(&fclones->fclone_ref);
+	    atomic_read(&fclones->fclone_ref) == 1) {
+		n = &fclones->skb2;
+		atomic_set(&fclones->fclone_ref, 2);
 	} else {
 		if (skb_pfmemalloc(skb))
 			gfp_mask |= __GFP_MEMALLOC;