[NET]: Implement SKB fast cloning.

Protocols that make extensive use of SKB cloning,
for example TCP, eat at least 2 allocations per
packet sent as a result.

To cut the kmalloc() count in half, we implement
a pre-allocation scheme wherein we allocate
2 sk_buff objects in advance, then use a simple
reference count to free up the memory at the
correct time.

Based upon an initial patch by Thomas Graf and
suggestions from Herbert Xu.

Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 1 insertions, 1 deletions

diff --git a/include/net/sock.h b/include/net/sock.h
index 14183883e8e6..d57aece9492c 100644
--- a/include/net/sock.h
+++ b/include/net/sock.h
@@ -1200,7 +1200,7 @@ static inline struct sk_buff *sk_stream_alloc_pskb(struct sock *sk,
         int hdr_len;
 
         hdr_len = SKB_DATA_ALIGN(sk->sk_prot->max_header);
-        skb = alloc_skb(size + hdr_len, gfp);
+        skb = alloc_skb_fclone(size + hdr_len, gfp);
         if (skb) {
                 skb->truesize += mem;
                 if (sk->sk_forward_alloc >= (int)skb->truesize ||