Commit 53794570 authored by Yousuk Seung's avatar Yousuk Seung Committed by David S. Miller
Browse files

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: default avatarYousuk Seung <ysseung@google.com>
Signed-off-by: default avatarNeal Cardwell <ncardwell@google.com>
Signed-off-by: default avatarPriyaranjan Jha <priyarjha@google.com>
Signed-off-by: default avatarSoheil Hassas Yeganeh <soheil@google.com>
Signed-off-by: default avatarYuchung Cheng <ycheng@google.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 7156d194

net/ipv4/tcp_bbr.c

+4 −1
Original line number Original line Diff line number Diff line
@@ -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->mode = BBR_DRAIN;	/* drain queue we created */

		bbr->pacing_gain = bbr_drain_gain;	/* pace slow to drain */

		bbr->pacing_gain = bbr_drain_gain;	/* pace slow to drain */

		bbr->cwnd_gain = bbr_high_gain;	/* maintain cwnd */

		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: */

	}	/* fall through to check if in-flight is already small: */

	if (bbr->mode == BBR_DRAIN &&

	if (bbr->mode == BBR_DRAIN &&

	    tcp_packets_in_flight(tcp_sk(sk)) <=

	    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);

	struct bbr *bbr = inet_csk_ca(sk);





	bbr->prior_cwnd = 0;

	bbr->prior_cwnd = 0;

	tp->snd_ssthresh = TCP_INFINITE_SSTHRESH;

	bbr->rtt_cnt = 0;

	bbr->rtt_cnt = 0;

	bbr->next_rtt_delivered = 0;

	bbr->next_rtt_delivered = 0;

	bbr->prev_ca_state = TCP_CA_Open;

	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)

static u32 bbr_ssthresh(struct sock *sk)

{

{

	bbr_save_cwnd(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,

static size_t bbr_get_info(struct sock *sk, u32 ext, int *attr,

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