From 53794570049d314742f156c99022914840a3d5ab Mon Sep 17 00:00:00 2001 From: Yousuk Seung Date: Fri, 16 Mar 2018 10:51:49 -0700 Subject: [PATCH] net-tcp_bbr: set tp->snd_ssthresh to BDP upon STARTUP exit Set tp->snd_ssthresh to BDP upon STARTUP exit. This allows us to check if a BBR flow exited STARTUP and the BDP at the time of STARTUP exit with SCM_TIMESTAMPING_OPT_STATS. Since BBR does not use snd_ssthresh this fix has no impact on BBR's behavior. Signed-off-by: Yousuk Seung Signed-off-by: Neal Cardwell Signed-off-by: Priyaranjan Jha Signed-off-by: Soheil Hassas Yeganeh Signed-off-by: Yuchung Cheng Signed-off-by: David S. Miller --- net/ipv4/tcp_bbr.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/net/ipv4/tcp_bbr.c b/net/ipv4/tcp_bbr.c index c92014cb1e16..158d105e76da 100644 --- a/net/ipv4/tcp_bbr.c +++ b/net/ipv4/tcp_bbr.c @@ -731,6 +731,8 @@ static void bbr_check_drain(struct sock *sk, const struct rate_sample *rs) bbr->mode = BBR_DRAIN; /* drain queue we created */ bbr->pacing_gain = bbr_drain_gain; /* pace slow to drain */ bbr->cwnd_gain = bbr_high_gain; /* maintain cwnd */ + tcp_sk(sk)->snd_ssthresh = + bbr_target_cwnd(sk, bbr_max_bw(sk), BBR_UNIT); } /* fall through to check if in-flight is already small: */ if (bbr->mode == BBR_DRAIN && tcp_packets_in_flight(tcp_sk(sk)) <= @@ -834,6 +836,7 @@ static void bbr_init(struct sock *sk) struct bbr *bbr = inet_csk_ca(sk); bbr->prior_cwnd = 0; + tp->snd_ssthresh = TCP_INFINITE_SSTHRESH; bbr->rtt_cnt = 0; bbr->next_rtt_delivered = 0; bbr->prev_ca_state = TCP_CA_Open; @@ -886,7 +889,7 @@ static u32 bbr_undo_cwnd(struct sock *sk) static u32 bbr_ssthresh(struct sock *sk) { bbr_save_cwnd(sk); - return TCP_INFINITE_SSTHRESH; /* BBR does not use ssthresh */ + return tcp_sk(sk)->snd_ssthresh; } static size_t bbr_get_info(struct sock *sk, u32 ext, int *attr,