diff options
Diffstat (limited to 'net/ipv4/tcp_input.c')
| -rw-r--r-- | net/ipv4/tcp_input.c | 40 |
1 files changed, 22 insertions, 18 deletions
diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c index 9902cf1abdf4..f563d2a88809 100644 --- a/net/ipv4/tcp_input.c +++ b/net/ipv4/tcp_input.c @@ -1130,7 +1130,12 @@ static bool tcp_check_dsack(struct sock *sk, const struct sk_buff *ack_skb, struct tcp_sacktag_state { int reord; int fack_count; - long rtt_us; /* RTT measured by SACKing never-retransmitted data */ + /* Timestamps for earliest and latest never-retransmitted segment + * that was SACKed. RTO needs the earliest RTT to stay conservative, + * but congestion control should still get an accurate delay signal. + */ + struct skb_mstamp first_sackt; + struct skb_mstamp last_sackt; int flag; }; @@ -1233,14 +1238,9 @@ static u8 tcp_sacktag_one(struct sock *sk, state->reord); if (!after(end_seq, tp->high_seq)) state->flag |= FLAG_ORIG_SACK_ACKED; - /* Pick the earliest sequence sacked for RTT */ - if (state->rtt_us < 0) { - struct skb_mstamp now; - - skb_mstamp_get(&now); - state->rtt_us = skb_mstamp_us_delta(&now, - xmit_time); - } + if (state->first_sackt.v64 == 0) + state->first_sackt = *xmit_time; + state->last_sackt = *xmit_time; } if (sacked & TCPCB_LOST) { @@ -3049,7 +3049,8 @@ static void tcp_ack_tstamp(struct sock *sk, struct sk_buff *skb, * arrived at the other end. */ static int tcp_clean_rtx_queue(struct sock *sk, int prior_fackets, - u32 prior_snd_una, long sack_rtt_us) + u32 prior_snd_una, + struct tcp_sacktag_state *sack) { const struct inet_connection_sock *icsk = inet_csk(sk); struct skb_mstamp first_ackt, last_ackt, now; @@ -3057,8 +3058,9 @@ static int tcp_clean_rtx_queue(struct sock *sk, int prior_fackets, u32 prior_sacked = tp->sacked_out; u32 reord = tp->packets_out; bool fully_acked = true; - long ca_seq_rtt_us = -1L; + long sack_rtt_us = -1L; long seq_rtt_us = -1L; + long ca_rtt_us = -1L; struct sk_buff *skb; u32 pkts_acked = 0; bool rtt_update; @@ -3147,7 +3149,11 @@ static int tcp_clean_rtx_queue(struct sock *sk, int prior_fackets, skb_mstamp_get(&now); if (likely(first_ackt.v64)) { seq_rtt_us = skb_mstamp_us_delta(&now, &first_ackt); - ca_seq_rtt_us = skb_mstamp_us_delta(&now, &last_ackt); + ca_rtt_us = skb_mstamp_us_delta(&now, &last_ackt); + } + if (sack->first_sackt.v64) { + sack_rtt_us = skb_mstamp_us_delta(&now, &sack->first_sackt); + ca_rtt_us = skb_mstamp_us_delta(&now, &sack->last_sackt); } rtt_update = tcp_ack_update_rtt(sk, flag, seq_rtt_us, sack_rtt_us); @@ -3178,10 +3184,8 @@ static int tcp_clean_rtx_queue(struct sock *sk, int prior_fackets, tp->fackets_out -= min(pkts_acked, tp->fackets_out); - if (ca_ops->pkts_acked) { - long rtt_us = min_t(ulong, ca_seq_rtt_us, sack_rtt_us); - ca_ops->pkts_acked(sk, pkts_acked, rtt_us); - } + if (ca_ops->pkts_acked) + ca_ops->pkts_acked(sk, pkts_acked, ca_rtt_us); } else if (skb && rtt_update && sack_rtt_us >= 0 && sack_rtt_us > skb_mstamp_us_delta(&now, &skb->skb_mstamp)) { @@ -3466,7 +3470,7 @@ static int tcp_ack(struct sock *sk, const struct sk_buff *skb, int flag) const int prior_unsacked = tp->packets_out - tp->sacked_out; int acked = 0; /* Number of packets newly acked */ - sack_state.rtt_us = -1L; + sack_state.first_sackt.v64 = 0; /* We very likely will need to access write queue head. */ prefetchw(sk->sk_write_queue.next); @@ -3555,7 +3559,7 @@ static int tcp_ack(struct sock *sk, const struct sk_buff *skb, int flag) /* See if we can take anything off of the retransmit queue. */ acked = tp->packets_out; flag |= tcp_clean_rtx_queue(sk, prior_fackets, prior_snd_una, - sack_state.rtt_us); + &sack_state); acked -= tp->packets_out; /* Advance cwnd if state allows */ |