[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/tcp_output.c b/net/ipv4/tcp_output.c
index ca406157724c..f63e99aac2d5 100644
--- a/net/ipv4/tcp_output.c
+++ b/net/ipv4/tcp_output.c
@@ -426,7 +426,6 @@ static int tcp_transmit_skb(struct sock *sk, struct sk_buff *skb, int clone_it,
 
         th = (struct tcphdr *) skb_push(skb, tcp_header_size);
         skb->h.th = th;
-        skb_set_owner_w(skb, sk);
 
         /* Build TCP header and checksum it. */
         th->source              = inet->sport;
@@ -479,7 +478,7 @@ static int tcp_transmit_skb(struct sock *sk, struct sk_buff *skb, int clone_it,
         if (after(tcb->end_seq, tp->snd_nxt) || tcb->seq == tcb->end_seq)
                 TCP_INC_STATS(TCP_MIB_OUTSEGS);
 
-        err = icsk->icsk_af_ops->queue_xmit(skb, 0);
+        err = icsk->icsk_af_ops->queue_xmit(skb, sk, 0);
         if (likely(err <= 0))
                 return err;