From e55a6d7a97044c2f4fd0231242e062924d75c7b6 Mon Sep 17 00:00:00 2001 From: Florin Coras Date: Wed, 31 Oct 2018 23:09:22 -0700 Subject: tcp: fast retransmit pacing Force pacing for fast retransmit to avoid bursts of retransmitted packets. Change-Id: I2ff42c328899b36322c4de557b1f7d853dba8fe2 Signed-off-by: Florin Coras --- src/vnet/session/session_node.c | 3 ++- src/vnet/session/transport.c | 40 +++++++++++++++++++++++++++------- src/vnet/session/transport_interface.h | 14 +++++++++--- 3 files changed, 45 insertions(+), 12 deletions(-) (limited to 'src/vnet/session') diff --git a/src/vnet/session/session_node.c b/src/vnet/session/session_node.c index 6ef461a5f34..34131723665 100644 --- a/src/vnet/session/session_node.c +++ b/src/vnet/session/session_node.c @@ -570,7 +570,8 @@ session_tx_fifo_read_and_snd_i (vlib_main_t * vm, vlib_node_runtime_t * node, ctx->tc = session_tx_get_transport (ctx, peek_data); ctx->snd_mss = ctx->transport_vft->send_mss (ctx->tc); ctx->snd_space = - transport_connection_max_tx_burst (ctx->tc, vm->clib_time.last_cpu_time); + transport_connection_snd_space (ctx->tc, vm->clib_time.last_cpu_time, + ctx->snd_mss); if (ctx->snd_space == 0 || ctx->snd_mss == 0) { vec_add1 (wrk->pending_event_vector, *e); diff --git a/src/vnet/session/transport.c b/src/vnet/session/transport.c index fefedcae8f2..0dd9ccd3213 100644 --- a/src/vnet/session/transport.c +++ b/src/vnet/session/transport.c @@ -497,9 +497,14 @@ static inline u32 spacer_max_burst (spacer_t * pacer, u64 norm_time_now) { u64 n_periods = norm_time_now - pacer->last_update; + u64 inc; + + if (n_periods > 0 && (inc = n_periods * pacer->tokens_per_period) > 10) + { + pacer->last_update = norm_time_now; + pacer->bucket += inc; + } - pacer->last_update = norm_time_now; - pacer->bucket += n_periods * pacer->tokens_per_period; return clib_min (pacer->bucket, pacer->max_burst_size); } @@ -525,17 +530,22 @@ spacer_set_pace_rate (spacer_t * pacer, u64 rate_bytes_per_sec) void transport_connection_tx_pacer_init (transport_connection_t * tc, - u32 rate_bytes_per_sec, u32 burst_bytes) + u32 rate_bytes_per_sec, + u32 initial_bucket) { vlib_main_t *vm = vlib_get_main (); u64 time_now = vm->clib_time.last_cpu_time; spacer_t *pacer = &tc->pacer; + f64 dispatch_period; + u32 burst_size; tc->flags |= TRANSPORT_CONNECTION_F_IS_TX_PACED; - spacer_update_max_burst_size (&tc->pacer, burst_bytes); + dispatch_period = transport_dispatch_period (tc->thread_index); + burst_size = rate_bytes_per_sec * dispatch_period; + spacer_update_max_burst_size (&tc->pacer, burst_size); spacer_set_pace_rate (&tc->pacer, rate_bytes_per_sec); pacer->last_update = time_now >> SPACER_CPU_TICKS_PER_PERIOD_SHIFT; - pacer->bucket = burst_bytes; + pacer->bucket = initial_bucket; } void @@ -550,17 +560,24 @@ transport_connection_tx_pacer_update (transport_connection_t * tc, } u32 -transport_connection_max_tx_burst (transport_connection_t * tc, u64 time_now) +transport_connection_tx_pacer_burst (transport_connection_t * tc, + u64 time_now) +{ + time_now >>= SPACER_CPU_TICKS_PER_PERIOD_SHIFT; + return spacer_max_burst (&tc->pacer, time_now); +} + +u32 +transport_connection_snd_space (transport_connection_t * tc, u64 time_now, + u16 mss) { u32 snd_space, max_paced_burst; - u32 mss; snd_space = tp_vfts[tc->proto].send_space (tc); if (transport_connection_is_tx_paced (tc)) { time_now >>= SPACER_CPU_TICKS_PER_PERIOD_SHIFT; max_paced_burst = spacer_max_burst (&tc->pacer, time_now); - mss = tp_vfts[tc->proto].send_mss (tc); max_paced_burst = (max_paced_burst < mss) ? 0 : max_paced_burst; snd_space = clib_min (snd_space, max_paced_burst); snd_space = snd_space - snd_space % mss; @@ -576,6 +593,13 @@ transport_connection_update_tx_stats (transport_connection_t * tc, u32 bytes) spacer_update_bucket (&tc->pacer, bytes); } +void +transport_connection_tx_pacer_update_bytes (transport_connection_t * tc, + u32 bytes) +{ + spacer_update_bucket (&tc->pacer, bytes); +} + void transport_init_tx_pacers_period (void) { diff --git a/src/vnet/session/transport_interface.h b/src/vnet/session/transport_interface.h index ce3bb7fab7c..b7aa4b7fa3c 100644 --- a/src/vnet/session/transport_interface.h +++ b/src/vnet/session/transport_interface.h @@ -111,7 +111,7 @@ void transport_enable_disable (vlib_main_t * vm, u8 is_en); */ void transport_connection_tx_pacer_init (transport_connection_t * tc, u32 rate_bytes_per_sec, - u32 burst_bytes); + u32 initial_bucket); /** * Update tx pacer pacing rate @@ -127,9 +127,13 @@ void transport_connection_tx_pacer_update (transport_connection_t * tc, * * @param tc transport connection * @param time_now current cpu time as returned by @ref clib_cpu_time_now + * @param mss transport's mss */ -u32 transport_connection_max_tx_burst (transport_connection_t * tc, - u64 time_now); +u32 transport_connection_snd_space (transport_connection_t * tc, + u64 time_now, u16 mss); + +u32 transport_connection_tx_pacer_burst (transport_connection_t * tc, + u64 time_now); /** * Initialize period for tx pacers @@ -163,6 +167,10 @@ u8 *format_transport_pacer (u8 * s, va_list * args); void transport_connection_update_tx_stats (transport_connection_t * tc, u32 bytes); +void +transport_connection_tx_pacer_update_bytes (transport_connection_t * tc, + u32 bytes); + #endif /* SRC_VNET_SESSION_TRANSPORT_INTERFACE_H_ */ /* -- cgit 1.2.3-korg