diff options
| -rw-r--r-- | net/ipv4/tcp_input.c | 38 |
1 files changed, 19 insertions, 19 deletions
diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c index 075ab4d..71fb37c 100644 --- a/net/ipv4/tcp_input.c +++ b/net/ipv4/tcp_input.c @@ -3358,34 +3358,34 @@ static void tcp_replace_ts_recent(struct tcp_sock *tp, u32 seq) } /* This routine deals with acks during a TLP episode. + * We mark the end of a TLP episode on receiving TLP dupack or when + * ack is after tlp_high_seq. * Ref: loss detection algorithm in draft-dukkipati-tcpm-tcp-loss-probe. */ static void tcp_process_tlp_ack(struct sock *sk, u32 ack, int flag) { struct tcp_sock *tp = tcp_sk(sk); - bool is_tlp_dupack = (ack == tp->tlp_high_seq) && - !(flag & (FLAG_SND_UNA_ADVANCED | - FLAG_NOT_DUP | FLAG_DATA_SACKED)); - /* Mark the end of TLP episode on receiving TLP dupack or when - * ack is after tlp_high_seq. - */ - if (is_tlp_dupack) { - tp->tlp_high_seq = 0; + if (before(ack, tp->tlp_high_seq)) return; - } - if (after(ack, tp->tlp_high_seq)) { + if (flag & FLAG_DSACKING_ACK) { + /* This DSACK means original and TLP probe arrived; no loss */ + tp->tlp_high_seq = 0; + } else if (after(ack, tp->tlp_high_seq)) { + /* ACK advances: there was a loss, so reduce cwnd. Reset + * tlp_high_seq in tcp_init_cwnd_reduction() + */ + tcp_init_cwnd_reduction(sk); + tcp_set_ca_state(sk, TCP_CA_CWR); + tcp_end_cwnd_reduction(sk); + tcp_try_keep_open(sk); + NET_INC_STATS_BH(sock_net(sk), + LINUX_MIB_TCPLOSSPROBERECOVERY); + } else if (!(flag & (FLAG_SND_UNA_ADVANCED | + FLAG_NOT_DUP | FLAG_DATA_SACKED))) { + /* Pure dupack: original and TLP probe arrived; no loss */ tp->tlp_high_seq = 0; - /* Don't reduce cwnd if DSACK arrives for TLP retrans. */ - if (!(flag & FLAG_DSACKING_ACK)) { - tcp_init_cwnd_reduction(sk); - tcp_set_ca_state(sk, TCP_CA_CWR); - tcp_end_cwnd_reduction(sk); - tcp_try_keep_open(sk); - NET_INC_STATS_BH(sock_net(sk), - LINUX_MIB_TCPLOSSPROBERECOVERY); - } } } |
