@@ -1730,9 +1730,16 @@ static void tcp_enter_frto_loss(struct sock *sk, int allowed_segments, int flag)
TCP_SKB_CB(skb)->sacked &= ~TCPCB_SACKED_RETRANS;
}
- /* Don't lost mark skbs that were fwd transmitted after RTO */
- if (!(TCP_SKB_CB(skb)->sacked&TCPCB_SACKED_ACKED) &&
- !after(TCP_SKB_CB(skb)->end_seq, tp->frto_highmark)) {
+ /* Marking forward transmissions that were made after RTO lost
+ * can cause unnecessary retransmissions in some scenarios,
+ * SACK blocks will mitigate that in some but not in all cases.
+ * We used to not mark them but it was causing break-ups with
+ * receivers that do only in-order receival.
+ *
+ * TODO: we could detect presence of such receiver and select
+ * different behavior per flow.
+ */
+ if (!(TCP_SKB_CB(skb)->sacked & TCPCB_SACKED_ACKED)) {
TCP_SKB_CB(skb)->sacked |= TCPCB_LOST;
tp->lost_out += tcp_skb_pcount(skb);
}
@@ -1748,7 +1755,7 @@ static void tcp_enter_frto_loss(struct sock *sk, int allowed_segments, int flag)
tp->reordering = min_t(unsigned int, tp->reordering,
sysctl_tcp_reordering);
tcp_set_ca_state(sk, TCP_CA_Loss);
- tp->high_seq = tp->frto_highmark;
+ tp->high_seq = tp->snd_nxt;
TCP_ECN_queue_cwr(tp);
tcp_clear_retrans_hints_partial(tp);