From 5bd370a63daf62bb5520c258f04e91a4d9d274dd Mon Sep 17 00:00:00 2001 From: Gerrit Renker Date: Mon, 17 Dec 2007 10:25:06 -0200 Subject: [PATCH] [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 Signed-off-by: Ian McDonald Signed-off-by: Arnaldo Carvalho de Melo Signed-off-by: David S. Miller --- net/dccp/ccids/ccid3.c | 173 ++++++++++++++++++++--------------------- 1 file changed, 84 insertions(+), 89 deletions(-) diff --git a/net/dccp/ccids/ccid3.c b/net/dccp/ccids/ccid3.c index e31560daa0..a93a556ad0 100644 --- a/net/dccp/ccids/ccid3.c +++ b/net/dccp/ccids/ccid3.c @@ -402,112 +402,107 @@ static void ccid3_hc_tx_packet_recv(struct sock *sk, struct sk_buff *skb) if (!(DCCP_SKB_CB(skb)->dccpd_type == DCCP_PKT_ACK || DCCP_SKB_CB(skb)->dccpd_type == DCCP_PKT_DATAACK)) return; + /* ... and only in the established state */ + if (hctx->ccid3hctx_state != TFRC_SSTATE_FBACK && + hctx->ccid3hctx_state != TFRC_SSTATE_NO_FBACK) + return; opt_recv = &hctx->ccid3hctx_options_received; + now = ktime_get_real(); - switch (hctx->ccid3hctx_state) { - case TFRC_SSTATE_NO_FBACK: - case TFRC_SSTATE_FBACK: - now = ktime_get_real(); - - /* estimate RTT from history if ACK number is valid */ - r_sample = tfrc_tx_hist_rtt(hctx->ccid3hctx_hist, - DCCP_SKB_CB(skb)->dccpd_ack_seq, now); - if (r_sample == 0) { - DCCP_WARN("%s(%p): %s with bogus ACK-%llu\n", dccp_role(sk), sk, - dccp_packet_name(DCCP_SKB_CB(skb)->dccpd_type), - (unsigned long long)DCCP_SKB_CB(skb)->dccpd_ack_seq); - return; - } + /* Estimate RTT from history if ACK number is valid */ + r_sample = tfrc_tx_hist_rtt(hctx->ccid3hctx_hist, + DCCP_SKB_CB(skb)->dccpd_ack_seq, now); + if (r_sample == 0) { + DCCP_WARN("%s(%p): %s with bogus ACK-%llu\n", dccp_role(sk), sk, + dccp_packet_name(DCCP_SKB_CB(skb)->dccpd_type), + (unsigned long long)DCCP_SKB_CB(skb)->dccpd_ack_seq); + return; + } + + /* Update receive rate in units of 64 * bytes/second */ + hctx->ccid3hctx_x_recv = opt_recv->ccid3or_receive_rate; + hctx->ccid3hctx_x_recv <<= 6; - /* Update receive rate in units of 64 * bytes/second */ - hctx->ccid3hctx_x_recv = opt_recv->ccid3or_receive_rate; - hctx->ccid3hctx_x_recv <<= 6; + /* Update loss event rate (which is scaled by 1e6) */ + pinv = opt_recv->ccid3or_loss_event_rate; + if (pinv == ~0U || pinv == 0) /* see RFC 4342, 8.5 */ + hctx->ccid3hctx_p = 0; + else /* can not exceed 100% */ + hctx->ccid3hctx_p = 1000000 / pinv; + /* + * Validate new RTT sample and update moving average + */ + r_sample = dccp_sample_rtt(sk, r_sample); + hctx->ccid3hctx_rtt = tfrc_ewma(hctx->ccid3hctx_rtt, r_sample, 9); - /* Update loss event rate */ - pinv = opt_recv->ccid3or_loss_event_rate; - if (pinv == ~0U || pinv == 0) /* see RFC 4342, 8.5 */ - hctx->ccid3hctx_p = 0; - else /* can not exceed 100% */ - hctx->ccid3hctx_p = 1000000 / pinv; + if (hctx->ccid3hctx_state == TFRC_SSTATE_NO_FBACK) { /* - * Validate new RTT sample and update moving average + * Larger Initial Windows [RFC 4342, sec. 5] */ - r_sample = dccp_sample_rtt(sk, r_sample); - hctx->ccid3hctx_rtt = tfrc_ewma(hctx->ccid3hctx_rtt, r_sample, 9); + hctx->ccid3hctx_x = rfc3390_initial_rate(sk); + hctx->ccid3hctx_t_ld = now; - if (hctx->ccid3hctx_state == TFRC_SSTATE_NO_FBACK) { - /* - * Larger Initial Windows [RFC 4342, sec. 5] - */ - hctx->ccid3hctx_x = rfc3390_initial_rate(sk); - hctx->ccid3hctx_t_ld = now; + ccid3_update_send_interval(hctx); - ccid3_update_send_interval(hctx); + ccid3_pr_debug("%s(%p), s=%u, MSS=%u, " + "R_sample=%uus, X=%u\n", dccp_role(sk), + sk, hctx->ccid3hctx_s, + dccp_sk(sk)->dccps_mss_cache, r_sample, + (unsigned)(hctx->ccid3hctx_x >> 6)); - ccid3_pr_debug("%s(%p), s=%u, MSS=%u, " - "R_sample=%uus, X=%u\n", dccp_role(sk), - sk, hctx->ccid3hctx_s, - dccp_sk(sk)->dccps_mss_cache, r_sample, - (unsigned)(hctx->ccid3hctx_x >> 6)); + ccid3_hc_tx_set_state(sk, TFRC_SSTATE_FBACK); + } else { - ccid3_hc_tx_set_state(sk, TFRC_SSTATE_FBACK); - } else { + /* Update sending rate (step 4 of [RFC 3448, 4.3]) */ + if (hctx->ccid3hctx_p > 0) + hctx->ccid3hctx_x_calc = + tfrc_calc_x(hctx->ccid3hctx_s, + hctx->ccid3hctx_rtt, + hctx->ccid3hctx_p); + ccid3_hc_tx_update_x(sk, &now); - /* Update sending rate (step 4 of [RFC 3448, 4.3]) */ - if (hctx->ccid3hctx_p > 0) - hctx->ccid3hctx_x_calc = - tfrc_calc_x(hctx->ccid3hctx_s, - hctx->ccid3hctx_rtt, - hctx->ccid3hctx_p); - ccid3_hc_tx_update_x(sk, &now); - - ccid3_pr_debug("%s(%p), RTT=%uus (sample=%uus), s=%u, " - "p=%u, X_calc=%u, X_recv=%u, X=%u\n", - dccp_role(sk), - sk, hctx->ccid3hctx_rtt, r_sample, - hctx->ccid3hctx_s, hctx->ccid3hctx_p, - hctx->ccid3hctx_x_calc, - (unsigned)(hctx->ccid3hctx_x_recv >> 6), - (unsigned)(hctx->ccid3hctx_x >> 6)); - } + ccid3_pr_debug("%s(%p), RTT=%uus (sample=%uus), s=%u, " + "p=%u, X_calc=%u, X_recv=%u, X=%u\n", + dccp_role(sk), + sk, hctx->ccid3hctx_rtt, r_sample, + hctx->ccid3hctx_s, hctx->ccid3hctx_p, + hctx->ccid3hctx_x_calc, + (unsigned)(hctx->ccid3hctx_x_recv >> 6), + (unsigned)(hctx->ccid3hctx_x >> 6)); + } - /* unschedule no feedback timer */ - sk_stop_timer(sk, &hctx->ccid3hctx_no_feedback_timer); + /* unschedule no feedback timer */ + sk_stop_timer(sk, &hctx->ccid3hctx_no_feedback_timer); - /* - * As we have calculated new ipi, delta, t_nom it is possible - * that we now can send a packet, so wake up dccp_wait_for_ccid - */ - sk->sk_write_space(sk); + /* + * As we have calculated new ipi, delta, t_nom it is possible + * that we now can send a packet, so wake up dccp_wait_for_ccid + */ + sk->sk_write_space(sk); - /* - * Update timeout interval for the nofeedback timer. - * We use a configuration option to increase the lower bound. - * This can help avoid triggering the nofeedback timer too - * often ('spinning') on LANs with small RTTs. - */ - hctx->ccid3hctx_t_rto = max_t(u32, 4 * hctx->ccid3hctx_rtt, - CONFIG_IP_DCCP_CCID3_RTO * - (USEC_PER_SEC/1000)); - /* - * Schedule no feedback timer to expire in - * max(t_RTO, 2 * s/X) = max(t_RTO, 2 * t_ipi) - */ - t_nfb = max(hctx->ccid3hctx_t_rto, 2 * hctx->ccid3hctx_t_ipi); + /* + * Update timeout interval for the nofeedback timer. + * We use a configuration option to increase the lower bound. + * This can help avoid triggering the nofeedback timer too + * often ('spinning') on LANs with small RTTs. + */ + hctx->ccid3hctx_t_rto = max_t(u32, 4 * hctx->ccid3hctx_rtt, + (CONFIG_IP_DCCP_CCID3_RTO * + (USEC_PER_SEC / 1000))); + /* + * Schedule no feedback timer to expire in + * max(t_RTO, 2 * s/X) = max(t_RTO, 2 * t_ipi) + */ + t_nfb = max(hctx->ccid3hctx_t_rto, 2 * hctx->ccid3hctx_t_ipi); - ccid3_pr_debug("%s(%p), Scheduled no feedback timer to " - "expire in %lu jiffies (%luus)\n", - dccp_role(sk), - sk, usecs_to_jiffies(t_nfb), t_nfb); + ccid3_pr_debug("%s(%p), Scheduled no feedback timer to " + "expire in %lu jiffies (%luus)\n", + dccp_role(sk), + sk, usecs_to_jiffies(t_nfb), t_nfb); - sk_reset_timer(sk, &hctx->ccid3hctx_no_feedback_timer, - jiffies + usecs_to_jiffies(t_nfb)); - break; - case TFRC_SSTATE_NO_SENT: /* fall through */ - case TFRC_SSTATE_TERM: /* ignore feedback when closing */ - break; - } + sk_reset_timer(sk, &hctx->ccid3hctx_no_feedback_timer, + jiffies + usecs_to_jiffies(t_nfb)); } static int ccid3_hc_tx_parse_options(struct sock *sk, unsigned char option, -- 2.39.5