From bf4d5ce58435d3f424749ff69650ea67ce778f04 Mon Sep 17 00:00:00 2001 From: Florin Coras Date: Fri, 19 Oct 2018 16:26:24 -0700 Subject: tcp: fast retransmit improvements Patch is too large to be ported to 18.10 just days before release. - handle fast retransmits outside of established node and limit the retransmit burst size to avoid tx losses and worsening congestion. - in the absance of a tx pacer, use slow start after fast retransmit exists - add fast retransmit heuristic that re-retries sending the first segment if everything else fails - fine tuning Change-Id: I84a2ab8fbba8b97f1d2b26584dc11a1e2c33c8d2 Signed-off-by: Florin Coras --- src/vnet/tcp/tcp.c | 16 ++++------------ 1 file changed, 4 insertions(+), 12 deletions(-) (limited to 'src/vnet/tcp/tcp.c') diff --git a/src/vnet/tcp/tcp.c b/src/vnet/tcp/tcp.c index e32b5c417ae..cb05b8c0533 100644 --- a/src/vnet/tcp/tcp.c +++ b/src/vnet/tcp/tcp.c @@ -950,7 +950,8 @@ format_tcp_scoreboard (u8 * s, va_list * args) hole = scoreboard_first_hole (sb); if (hole) - s = format (s, "\n head %u tail %u holes:\n", sb->head, sb->tail); + s = format (s, "\n head %u tail %u %u holes:\n", sb->head, sb->tail, + pool_elts (sb->holes)); while (hole) { @@ -1027,7 +1028,7 @@ tcp_snd_space_inline (tcp_connection_t * tc) { int snd_space, snt_limited; - if (PREDICT_TRUE (tcp_in_cong_recovery (tc) == 0)) + if (PREDICT_TRUE (!tcp_in_fastrecovery (tc))) { snd_space = tcp_available_output_snd_space (tc); @@ -1047,16 +1048,6 @@ tcp_snd_space_inline (tcp_connection_t * tc) return tcp_round_snd_space (tc, snd_space); } - if (tcp_in_recovery (tc)) - { - tc->snd_nxt = tc->snd_una_max; - snd_space = tcp_available_snd_wnd (tc) - tc->snd_rxt_bytes - - (tc->snd_una_max - tc->snd_congestion); - if (snd_space <= 0 || (tc->snd_una_max - tc->snd_una) >= tc->snd_wnd) - return 0; - return tcp_round_snd_space (tc, snd_space); - } - /* RFC 5681: When previously unsent data is available and the new value of * cwnd and the receiver's advertised window allow, a TCP SHOULD send 1*SMSS * bytes of previously unsent data. */ @@ -1103,6 +1094,7 @@ tcp_update_time (f64 now, u8 thread_index) tw_timer_expire_timers_16t_2w_512sl (&tcp_main. wrk_ctx[thread_index].timer_wheel, now); + tcp_do_fastretransmits (thread_index); tcp_flush_frames_to_output (thread_index); } -- cgit 1.2.3-korg