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 <ysse...@google.com>
Signed-off-by: Neal Cardwell <ncardw...@google.com>
Signed-off-by: Priyaranjan Jha <priyar...@google.com>
Signed-off-by: Soheil Hassas Yeganeh <soh...@google.com>
Signed-off-by: Yuchung Cheng <ych...@google.com>
---
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,
--
2.16.2.804.g6dcf76e118-goog
