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| author | Eric Dumazet <edumazet@google.com> | 2016-04-01 08:52:21 -0700 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2016-04-04 22:11:20 -0400 |
| commit | a9d6532b567489196dac4ce60c62343e43228759 (patch) | |
| tree | 950186e21f38670eb26eca351a96970a613494ad /net | |
| parent | 9caad864151e525929d323de96cad382da49c3b2 (diff) | |
| download | linux-stable-a9d6532b567489196dac4ce60c62343e43228759.tar.gz linux-stable-a9d6532b567489196dac4ce60c62343e43228759.tar.bz2 linux-stable-a9d6532b567489196dac4ce60c62343e43228759.zip | |
ipv4: tcp: set SOCK_USE_WRITE_QUEUE for ip_send_unicast_reply()
TCP uses per cpu 'sockets' to send some packets :
- RST packets ( tcp_v4_send_reset()) )
- ACK packets for SYN_RECV and TIMEWAIT sockets
By setting SOCK_USE_WRITE_QUEUE flag, we tell sock_wfree()
to not call sk_write_space() since these internal sockets
do not care.
This gives a small performance improvement, merely by allowing
cpu to properly predict the sock_wfree() conditional branch,
and avoiding one atomic operation.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net')
| -rw-r--r-- | net/ipv4/tcp_ipv4.c | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/net/ipv4/tcp_ipv4.c b/net/ipv4/tcp_ipv4.c index f3ce0afe70aa..456ff3d6a132 100644 --- a/net/ipv4/tcp_ipv4.c +++ b/net/ipv4/tcp_ipv4.c @@ -2384,6 +2384,7 @@ static int __net_init tcp_sk_init(struct net *net) IPPROTO_TCP, net); if (res) goto fail; + sock_set_flag(sk, SOCK_USE_WRITE_QUEUE); *per_cpu_ptr(net->ipv4.tcp_sk, cpu) = sk; } |