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-rw-r--r--net/ipv4/tcp_bbr.c10
1 files changed, 9 insertions, 1 deletions
diff --git a/net/ipv4/tcp_bbr.c b/net/ipv4/tcp_bbr.c
index 42e0017f2ebc..69ee877574d0 100644
--- a/net/ipv4/tcp_bbr.c
+++ b/net/ipv4/tcp_bbr.c
@@ -112,7 +112,8 @@ struct bbr {
cwnd_gain:10, /* current gain for setting cwnd */
full_bw_cnt:3, /* number of rounds without large bw gains */
cycle_idx:3, /* current index in pacing_gain cycle array */
- unused_b:6;
+ has_seen_rtt:1, /* have we seen an RTT sample yet? */
+ unused_b:5;
u32 prior_cwnd; /* prior cwnd upon entering loss recovery */
u32 full_bw; /* recent bw, to estimate if pipe is full */
};
@@ -225,11 +226,13 @@ static u32 bbr_bw_to_pacing_rate(struct sock *sk, u32 bw, int gain)
static void bbr_init_pacing_rate_from_rtt(struct sock *sk)
{
struct tcp_sock *tp = tcp_sk(sk);
+ struct bbr *bbr = inet_csk_ca(sk);
u64 bw;
u32 rtt_us;
if (tp->srtt_us) { /* any RTT sample yet? */
rtt_us = max(tp->srtt_us >> 3, 1U);
+ bbr->has_seen_rtt = 1;
} else { /* no RTT sample yet */
rtt_us = USEC_PER_MSEC; /* use nominal default RTT */
}
@@ -247,8 +250,12 @@ static void bbr_init_pacing_rate_from_rtt(struct sock *sk)
*/
static void bbr_set_pacing_rate(struct sock *sk, u32 bw, int gain)
{
+ struct tcp_sock *tp = tcp_sk(sk);
+ struct bbr *bbr = inet_csk_ca(sk);
u32 rate = bbr_bw_to_pacing_rate(sk, bw, gain);
+ if (unlikely(!bbr->has_seen_rtt && tp->srtt_us))
+ bbr_init_pacing_rate_from_rtt(sk);
if (bbr_full_bw_reached(sk) || rate > sk->sk_pacing_rate)
sk->sk_pacing_rate = rate;
}
@@ -837,6 +844,7 @@ static void bbr_init(struct sock *sk)
minmax_reset(&bbr->bw, bbr->rtt_cnt, 0); /* init max bw to 0 */
+ bbr->has_seen_rtt = 0;
bbr_init_pacing_rate_from_rtt(sk);
bbr->restore_cwnd = 0;