diff options
| author | Eric Dumazet <edumazet@google.com> | 2014-09-23 03:29:32 +0400 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2014-09-26 23:40:06 +0400 |
| commit | f4a775d14489a801a5b8b0540e23ab82e2703091 (patch) | |
| tree | fea57ec3004b0586f0fc25f4cf3f0dc8631dcb5f /net/ipv4/tcp_output.c | |
| parent | aebac744932439b5f869869f07f406a9cced465d (diff) | |
| download | linux-f4a775d14489a801a5b8b0540e23ab82e2703091.tar.xz | |
net: introduce __skb_header_release()
While profiling TCP stack, I noticed one useless atomic operation
in tcp_sendmsg(), caused by skb_header_release().
It turns out all current skb_header_release() users have a fresh skb,
that no other user can see, so we can avoid one atomic operation.
Introduce __skb_header_release() to clearly document this.
This gave me a 1.5 % improvement on TCP_RR workload.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/ipv4/tcp_output.c')
| -rw-r--r-- | net/ipv4/tcp_output.c | 10 |
1 files changed, 5 insertions, 5 deletions
diff --git a/net/ipv4/tcp_output.c b/net/ipv4/tcp_output.c index 8c61a7c0c889..f173b1c4f815 100644 --- a/net/ipv4/tcp_output.c +++ b/net/ipv4/tcp_output.c @@ -995,7 +995,7 @@ static void tcp_queue_skb(struct sock *sk, struct sk_buff *skb) /* Advance write_seq and place onto the write_queue. */ tp->write_seq = TCP_SKB_CB(skb)->end_seq; - skb_header_release(skb); + __skb_header_release(skb); tcp_add_write_queue_tail(sk, skb); sk->sk_wmem_queued += skb->truesize; sk_mem_charge(sk, skb->truesize); @@ -1167,7 +1167,7 @@ int tcp_fragment(struct sock *sk, struct sk_buff *skb, u32 len, } /* Link BUFF into the send queue. */ - skb_header_release(buff); + __skb_header_release(buff); tcp_insert_write_queue_after(skb, buff, sk); return 0; @@ -1671,7 +1671,7 @@ static int tso_fragment(struct sock *sk, struct sk_buff *skb, unsigned int len, tcp_set_skb_tso_segs(sk, buff, mss_now); /* Link BUFF into the send queue. */ - skb_header_release(buff); + __skb_header_release(buff); tcp_insert_write_queue_after(skb, buff, sk); return 0; @@ -2772,7 +2772,7 @@ int tcp_send_synack(struct sock *sk) if (nskb == NULL) return -ENOMEM; tcp_unlink_write_queue(skb, sk); - skb_header_release(nskb); + __skb_header_release(nskb); __tcp_add_write_queue_head(sk, nskb); sk_wmem_free_skb(sk, skb); sk->sk_wmem_queued += nskb->truesize; @@ -2947,7 +2947,7 @@ static void tcp_connect_queue_skb(struct sock *sk, struct sk_buff *skb) struct tcp_skb_cb *tcb = TCP_SKB_CB(skb); tcb->end_seq += skb->len; - skb_header_release(skb); + __skb_header_release(skb); __tcp_add_write_queue_tail(sk, skb); sk->sk_wmem_queued += skb->truesize; sk_mem_charge(sk, skb->truesize); |