Lines Matching full:rtt
37 * Kernel only stores RTT and RTTVAR in usec resolution
347 unsigned long rtt;
357 /* This session failed to estimate rtt. Why?
371 rtt = tcp_metric_get(tm, TCP_METRIC_RTT);
372 m = rtt - tp->srtt_us;
374 /* If newly calculated rtt larger than stored one, store new
375 * one. Otherwise, use EWMA. Remember, rtt overestimation is
380 rtt = tp->srtt_us;
382 rtt -= (m >> 3);
383 tcp_metric_set(tm, TCP_METRIC_RTT, rtt);
470 u32 val, crtt = 0; /* cached RTT scaled by 8 */
504 /* The initial RTT measurement from the SYN/SYN-ACK is not ideal
507 * the RTT estimator variables intact (e.g., srtt, mdev, rttvar).
509 * data RTT sample (tcp_rtt_estimator()). Hence the cached RTT only
510 * influences the first RTO but not later RTT estimation.
512 * But if RTT is not available from the SYN (due to retransmits or
515 * A bit of theory. RTT is time passed after "normal" sized packet
519 * NEVER underestimate RTT. BUT! If peer tries to make some clever
520 * tricks sort of "quick acks" for time long enough to decrease RTT
525 /* Set RTO like tcp_rtt_estimator(), but from cached RTT. */
529 /* RFC6298: 5.7 We've failed to get a valid RTT sample from