4 /* Record the most recently (re)sent time among the (s)acked packets */
5 void tcp_rack_advance(struct tcp_sock *tp,
6 const struct skb_mstamp *xmit_time, u8 sacked)
8 if (tp->rack.mstamp.v64 &&
9 !skb_mstamp_after(xmit_time, &tp->rack.mstamp))
12 if (sacked & TCPCB_RETRANS) {
13 struct skb_mstamp now;
15 /* If the sacked packet was retransmitted, it's ambiguous
16 * whether the retransmission or the original (or the prior
17 * retransmission) was sacked.
19 * If the original is lost, there is no ambiguity. Otherwise
20 * we assume the original can be delayed up to aRTT + min_rtt.
21 * the aRTT term is bounded by the fast recovery or timeout,
22 * so it's at least one RTT (i.e., retransmission is at least
26 if (skb_mstamp_us_delta(&now, xmit_time) < tcp_min_rtt(tp))
30 tp->rack.mstamp = *xmit_time;
31 tp->rack.advanced = 1;