From 35cd141b4bf51dc43e3b03245c4e5428f1707c40 Mon Sep 17 00:00:00 2001 From: Michael Tuexen Date: Sat, 16 Nov 2019 11:37:26 +0000 Subject: [PATCH] Implement a tCP CUBIC-specific after idle reaction. This patch addresses a very common case of frequent application stalls, where TCP runs idle and looses the state of the network. Submitted by: Richard Scheffenegger Reviewed by: Cheng Cui Differential Revision: https://reviews.freebsd.org/D18954 --- sys/netinet/cc/cc_cubic.c | 22 +++++++++++++++++++--- 1 file changed, 19 insertions(+), 3 deletions(-) diff --git a/sys/netinet/cc/cc_cubic.c b/sys/netinet/cc/cc_cubic.c index 033fac9b80dc..831c5b369278 100644 --- a/sys/netinet/cc/cc_cubic.c +++ b/sys/netinet/cc/cc_cubic.c @@ -78,6 +78,7 @@ static int cubic_mod_init(void); static void cubic_post_recovery(struct cc_var *ccv); static void cubic_record_rtt(struct cc_var *ccv); static void cubic_ssthresh_update(struct cc_var *ccv); +static void cubic_after_idle(struct cc_var *ccv); struct cubic { /* Cubic K in fixed point form with CUBIC_SHIFT worth of precision. */ @@ -112,6 +113,7 @@ struct cc_algo cubic_cc_algo = { .conn_init = cubic_conn_init, .mod_init = cubic_mod_init, .post_recovery = cubic_post_recovery, + .after_idle = cubic_after_idle, }; static void @@ -192,6 +194,23 @@ cubic_ack_received(struct cc_var *ccv, uint16_t type) } } +/* + * This is a Cubic specific implementation of after_idle. + * - Reset cwnd by calling New Reno implementation of after_idle. + * - Reset t_last_cong. + */ +static void +cubic_after_idle(struct cc_var *ccv) +{ + struct cubic *cubic_data; + + cubic_data = ccv->cc_data; + + newreno_cc_algo.after_idle(ccv); + cubic_data->t_last_cong = ticks; +} + + static void cubic_cb_destroy(struct cc_var *ccv) { @@ -287,9 +306,6 @@ cubic_conn_init(struct cc_var *ccv) static int cubic_mod_init(void) { - - cubic_cc_algo.after_idle = newreno_cc_algo.after_idle; - return (0); }