[TCP]: Don't set SKB owner in tcp_transmit_skb().

The data itself is already charged to the SKB, doing
the skb_set_owner_w() just generates a lot of noise and
extra atomics we don't really need.

Lmbench improvements on lat_tcp are minimal:

before:
TCP latency using localhost: 23.2701 microseconds
TCP latency using localhost: 23.1994 microseconds
TCP latency using localhost: 23.2257 microseconds

after:
TCP latency using localhost: 22.8380 microseconds
TCP latency using localhost: 22.9465 microseconds
TCP latency using localhost: 22.8462 microseconds

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

1 files changed, 1 insertions, 2 deletions

diff --git a/net/ipv4/ip_output.c b/net/ipv4/ip_output.c
index 23633bf042ba..def32d8d3b06 100644
--- a/net/ipv4/ip_output.c
+++ b/net/ipv4/ip_output.c
@@ -288,9 +288,8 @@ int ip_output(struct sk_buff *skb)
                             !(IPCB(skb)->flags & IPSKB_REROUTED));
 }
 
-int ip_queue_xmit(struct sk_buff *skb, int ipfragok)
+int ip_queue_xmit(struct sk_buff *skb, struct sock *sk, int ipfragok)
 {
-        struct sock *sk = skb->sk;
         struct inet_sock *inet = inet_sk(sk);
         struct ip_options *opt = inet->opt;
         struct rtable *rt;