diff options
| author | Wei Wang <weiwan@google.com> | 2017-05-05 12:53:23 -0700 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2017-05-08 14:37:07 -0400 |
| commit | 1b1fc3fddabfb8739ef2c8f04e05a9858b42c1f7 (patch) | |
| tree | 96e7fc35b0e4ab664d4e68a0ed7a68398402090c | |
| parent | 82486aa6f1b9bc8145e6d0fa2bc0b44307f3b875 (diff) | |
| download | linux-1b1fc3fddabfb8739ef2c8f04e05a9858b42c1f7.tar.bz2 | |
tcp: make congestion control optionally skip slow start after idle
Congestion control modules that want full control over congestion
control behavior do not want the cwnd modifications controlled by
the sysctl_tcp_slow_start_after_idle code path.
So skip those code paths for CC modules that use the cong_control()
API.
As an example, those cwnd effects are not desired for the BBR congestion
control algorithm.
Fixes: c0402760f565 ("tcp: new CC hook to set sending rate with rate_sample in any CA state")
Signed-off-by: Wei Wang <weiwan@google.com>
Signed-off-by: Yuchung Cheng <ycheng@google.com>
Signed-off-by: Neal Cardwell <ncardwell@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
| -rw-r--r-- | include/net/tcp.h | 4 | ||||
| -rw-r--r-- | net/ipv4/tcp_output.c | 4 |
2 files changed, 6 insertions, 2 deletions
diff --git a/include/net/tcp.h b/include/net/tcp.h index 8c0e5a901d64..38a7427ae902 100644 --- a/include/net/tcp.h +++ b/include/net/tcp.h @@ -1234,10 +1234,12 @@ void tcp_cwnd_restart(struct sock *sk, s32 delta); static inline void tcp_slow_start_after_idle_check(struct sock *sk) { + const struct tcp_congestion_ops *ca_ops = inet_csk(sk)->icsk_ca_ops; struct tcp_sock *tp = tcp_sk(sk); s32 delta; - if (!sysctl_tcp_slow_start_after_idle || tp->packets_out) + if (!sysctl_tcp_slow_start_after_idle || tp->packets_out || + ca_ops->cong_control) return; delta = tcp_time_stamp - tp->lsndtime; if (delta > inet_csk(sk)->icsk_rto) diff --git a/net/ipv4/tcp_output.c b/net/ipv4/tcp_output.c index 60111a0fc201..4858e190f6ac 100644 --- a/net/ipv4/tcp_output.c +++ b/net/ipv4/tcp_output.c @@ -1514,6 +1514,7 @@ static void tcp_cwnd_application_limited(struct sock *sk) static void tcp_cwnd_validate(struct sock *sk, bool is_cwnd_limited) { + const struct tcp_congestion_ops *ca_ops = inet_csk(sk)->icsk_ca_ops; struct tcp_sock *tp = tcp_sk(sk); /* Track the maximum number of outstanding packets in each @@ -1536,7 +1537,8 @@ static void tcp_cwnd_validate(struct sock *sk, bool is_cwnd_limited) tp->snd_cwnd_used = tp->packets_out; if (sysctl_tcp_slow_start_after_idle && - (s32)(tcp_time_stamp - tp->snd_cwnd_stamp) >= inet_csk(sk)->icsk_rto) + (s32)(tcp_time_stamp - tp->snd_cwnd_stamp) >= inet_csk(sk)->icsk_rto && + !ca_ops->cong_control) tcp_cwnd_application_limited(sk); /* The following conditions together indicate the starvation |