[CCID3]: Remove two irrelevant states in TX feedback handling
* the NO_SENT state is only triggered in bidirectional mode, costing unnecessary processing. * the TERM (terminating) state is irrelevant. Signed-off-by: Gerrit Renker <gerrit@erg.abdn.ac.uk> Signed-off-by: Ian McDonald <ian.mcdonald@jandi.co.nz> Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Gerrit Renker
David S. Miller
parent
8e138e7949
commit
5bd370a63d
@ -402,112 +402,107 @@ static void ccid3_hc_tx_packet_recv(struct sock *sk, struct sk_buff *skb)
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if (!(DCCP_SKB_CB(skb)->dccpd_type == DCCP_PKT_ACK ||
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DCCP_SKB_CB(skb)->dccpd_type == DCCP_PKT_DATAACK))
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return;
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/* ... and only in the established state */
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if (hctx->ccid3hctx_state != TFRC_SSTATE_FBACK &&
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hctx->ccid3hctx_state != TFRC_SSTATE_NO_FBACK)
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return;
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opt_recv = &hctx->ccid3hctx_options_received;
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now = ktime_get_real();
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switch (hctx->ccid3hctx_state) {
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case TFRC_SSTATE_NO_FBACK:
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case TFRC_SSTATE_FBACK:
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now = ktime_get_real();
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/* estimate RTT from history if ACK number is valid */
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r_sample = tfrc_tx_hist_rtt(hctx->ccid3hctx_hist,
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DCCP_SKB_CB(skb)->dccpd_ack_seq, now);
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if (r_sample == 0) {
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DCCP_WARN("%s(%p): %s with bogus ACK-%llu\n", dccp_role(sk), sk,
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dccp_packet_name(DCCP_SKB_CB(skb)->dccpd_type),
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(unsigned long long)DCCP_SKB_CB(skb)->dccpd_ack_seq);
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return;
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}
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/* Update receive rate in units of 64 * bytes/second */
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hctx->ccid3hctx_x_recv = opt_recv->ccid3or_receive_rate;
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hctx->ccid3hctx_x_recv <<= 6;
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/* Update loss event rate */
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pinv = opt_recv->ccid3or_loss_event_rate;
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if (pinv == ~0U || pinv == 0) /* see RFC 4342, 8.5 */
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hctx->ccid3hctx_p = 0;
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else /* can not exceed 100% */
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hctx->ccid3hctx_p = 1000000 / pinv;
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/*
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* Validate new RTT sample and update moving average
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*/
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r_sample = dccp_sample_rtt(sk, r_sample);
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hctx->ccid3hctx_rtt = tfrc_ewma(hctx->ccid3hctx_rtt, r_sample, 9);
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if (hctx->ccid3hctx_state == TFRC_SSTATE_NO_FBACK) {
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/*
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* Larger Initial Windows [RFC 4342, sec. 5]
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*/
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hctx->ccid3hctx_x = rfc3390_initial_rate(sk);
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hctx->ccid3hctx_t_ld = now;
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ccid3_update_send_interval(hctx);
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ccid3_pr_debug("%s(%p), s=%u, MSS=%u, "
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"R_sample=%uus, X=%u\n", dccp_role(sk),
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sk, hctx->ccid3hctx_s,
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dccp_sk(sk)->dccps_mss_cache, r_sample,
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(unsigned)(hctx->ccid3hctx_x >> 6));
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ccid3_hc_tx_set_state(sk, TFRC_SSTATE_FBACK);
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} else {
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/* Update sending rate (step 4 of [RFC 3448, 4.3]) */
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if (hctx->ccid3hctx_p > 0)
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hctx->ccid3hctx_x_calc =
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tfrc_calc_x(hctx->ccid3hctx_s,
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hctx->ccid3hctx_rtt,
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hctx->ccid3hctx_p);
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ccid3_hc_tx_update_x(sk, &now);
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ccid3_pr_debug("%s(%p), RTT=%uus (sample=%uus), s=%u, "
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"p=%u, X_calc=%u, X_recv=%u, X=%u\n",
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dccp_role(sk),
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sk, hctx->ccid3hctx_rtt, r_sample,
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hctx->ccid3hctx_s, hctx->ccid3hctx_p,
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hctx->ccid3hctx_x_calc,
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(unsigned)(hctx->ccid3hctx_x_recv >> 6),
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(unsigned)(hctx->ccid3hctx_x >> 6));
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}
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/* unschedule no feedback timer */
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sk_stop_timer(sk, &hctx->ccid3hctx_no_feedback_timer);
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/*
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* As we have calculated new ipi, delta, t_nom it is possible
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* that we now can send a packet, so wake up dccp_wait_for_ccid
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*/
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sk->sk_write_space(sk);
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/*
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* Update timeout interval for the nofeedback timer.
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* We use a configuration option to increase the lower bound.
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* This can help avoid triggering the nofeedback timer too
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* often ('spinning') on LANs with small RTTs.
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*/
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hctx->ccid3hctx_t_rto = max_t(u32, 4 * hctx->ccid3hctx_rtt,
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CONFIG_IP_DCCP_CCID3_RTO *
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(USEC_PER_SEC/1000));
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/*
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* Schedule no feedback timer to expire in
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* max(t_RTO, 2 * s/X) = max(t_RTO, 2 * t_ipi)
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*/
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t_nfb = max(hctx->ccid3hctx_t_rto, 2 * hctx->ccid3hctx_t_ipi);
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ccid3_pr_debug("%s(%p), Scheduled no feedback timer to "
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"expire in %lu jiffies (%luus)\n",
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dccp_role(sk),
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sk, usecs_to_jiffies(t_nfb), t_nfb);
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sk_reset_timer(sk, &hctx->ccid3hctx_no_feedback_timer,
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jiffies + usecs_to_jiffies(t_nfb));
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break;
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case TFRC_SSTATE_NO_SENT: /* fall through */
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case TFRC_SSTATE_TERM: /* ignore feedback when closing */
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break;
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/* Estimate RTT from history if ACK number is valid */
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r_sample = tfrc_tx_hist_rtt(hctx->ccid3hctx_hist,
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DCCP_SKB_CB(skb)->dccpd_ack_seq, now);
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if (r_sample == 0) {
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DCCP_WARN("%s(%p): %s with bogus ACK-%llu\n", dccp_role(sk), sk,
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dccp_packet_name(DCCP_SKB_CB(skb)->dccpd_type),
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(unsigned long long)DCCP_SKB_CB(skb)->dccpd_ack_seq);
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return;
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}
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/* Update receive rate in units of 64 * bytes/second */
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hctx->ccid3hctx_x_recv = opt_recv->ccid3or_receive_rate;
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hctx->ccid3hctx_x_recv <<= 6;
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/* Update loss event rate (which is scaled by 1e6) */
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pinv = opt_recv->ccid3or_loss_event_rate;
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if (pinv == ~0U || pinv == 0) /* see RFC 4342, 8.5 */
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hctx->ccid3hctx_p = 0;
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else /* can not exceed 100% */
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hctx->ccid3hctx_p = 1000000 / pinv;
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/*
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* Validate new RTT sample and update moving average
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*/
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r_sample = dccp_sample_rtt(sk, r_sample);
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hctx->ccid3hctx_rtt = tfrc_ewma(hctx->ccid3hctx_rtt, r_sample, 9);
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if (hctx->ccid3hctx_state == TFRC_SSTATE_NO_FBACK) {
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/*
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* Larger Initial Windows [RFC 4342, sec. 5]
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*/
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hctx->ccid3hctx_x = rfc3390_initial_rate(sk);
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hctx->ccid3hctx_t_ld = now;
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ccid3_update_send_interval(hctx);
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ccid3_pr_debug("%s(%p), s=%u, MSS=%u, "
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"R_sample=%uus, X=%u\n", dccp_role(sk),
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sk, hctx->ccid3hctx_s,
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dccp_sk(sk)->dccps_mss_cache, r_sample,
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(unsigned)(hctx->ccid3hctx_x >> 6));
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ccid3_hc_tx_set_state(sk, TFRC_SSTATE_FBACK);
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} else {
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/* Update sending rate (step 4 of [RFC 3448, 4.3]) */
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if (hctx->ccid3hctx_p > 0)
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hctx->ccid3hctx_x_calc =
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tfrc_calc_x(hctx->ccid3hctx_s,
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hctx->ccid3hctx_rtt,
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hctx->ccid3hctx_p);
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ccid3_hc_tx_update_x(sk, &now);
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ccid3_pr_debug("%s(%p), RTT=%uus (sample=%uus), s=%u, "
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"p=%u, X_calc=%u, X_recv=%u, X=%u\n",
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dccp_role(sk),
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sk, hctx->ccid3hctx_rtt, r_sample,
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hctx->ccid3hctx_s, hctx->ccid3hctx_p,
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hctx->ccid3hctx_x_calc,
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(unsigned)(hctx->ccid3hctx_x_recv >> 6),
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(unsigned)(hctx->ccid3hctx_x >> 6));
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}
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/* unschedule no feedback timer */
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sk_stop_timer(sk, &hctx->ccid3hctx_no_feedback_timer);
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/*
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* As we have calculated new ipi, delta, t_nom it is possible
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* that we now can send a packet, so wake up dccp_wait_for_ccid
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*/
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sk->sk_write_space(sk);
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/*
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* Update timeout interval for the nofeedback timer.
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* We use a configuration option to increase the lower bound.
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* This can help avoid triggering the nofeedback timer too
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* often ('spinning') on LANs with small RTTs.
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*/
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hctx->ccid3hctx_t_rto = max_t(u32, 4 * hctx->ccid3hctx_rtt,
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(CONFIG_IP_DCCP_CCID3_RTO *
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(USEC_PER_SEC / 1000)));
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/*
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* Schedule no feedback timer to expire in
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* max(t_RTO, 2 * s/X) = max(t_RTO, 2 * t_ipi)
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*/
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t_nfb = max(hctx->ccid3hctx_t_rto, 2 * hctx->ccid3hctx_t_ipi);
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ccid3_pr_debug("%s(%p), Scheduled no feedback timer to "
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"expire in %lu jiffies (%luus)\n",
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dccp_role(sk),
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sk, usecs_to_jiffies(t_nfb), t_nfb);
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sk_reset_timer(sk, &hctx->ccid3hctx_no_feedback_timer,
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jiffies + usecs_to_jiffies(t_nfb));
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}
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static int ccid3_hc_tx_parse_options(struct sock *sk, unsigned char option,
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