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| author | Eric Dumazet <edumazet@google.com> | 2014-09-22 16:29:32 -0700 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2014-09-26 15:40:06 -0400 |
| commit | f4a775d14489a801a5b8b0540e23ab82e2703091 (patch) | |
| tree | fea57ec3004b0586f0fc25f4cf3f0dc8631dcb5f /net/ipv4/tcp.c | |
| parent | aebac744932439b5f869869f07f406a9cced465d (diff) | |
| download | lwn-f4a775d14489a801a5b8b0540e23ab82e2703091.tar.gz lwn-f4a775d14489a801a5b8b0540e23ab82e2703091.zip | |
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.c')
| -rw-r--r-- | net/ipv4/tcp.c | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c index 070aeff1b131..553b01f52f71 100644 --- a/net/ipv4/tcp.c +++ b/net/ipv4/tcp.c @@ -609,7 +609,7 @@ static inline bool forced_push(const struct tcp_sock *tp) return after(tp->write_seq, tp->pushed_seq + (tp->max_window >> 1)); } -static inline void skb_entail(struct sock *sk, struct sk_buff *skb) +static void skb_entail(struct sock *sk, struct sk_buff *skb) { struct tcp_sock *tp = tcp_sk(sk); struct tcp_skb_cb *tcb = TCP_SKB_CB(skb); @@ -618,7 +618,7 @@ static inline void skb_entail(struct sock *sk, struct sk_buff *skb) tcb->seq = tcb->end_seq = tp->write_seq; tcb->tcp_flags = TCPHDR_ACK; tcb->sacked = 0; - 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); |