From c44a558164a466a74a4c10d4e7d7dd1b9a4b01dd Mon Sep 17 00:00:00 2001 From: Florin Coras Date: Thu, 1 Nov 2018 16:30:54 -0700 Subject: [PATCH] session: measure dispatch period only if under load Also reset pacer on tcp retransmit timeout Change-Id: I5a9edee4c00d1d169248d79587a9b10437c2bd87 Signed-off-by: Florin Coras --- src/vnet/session/session.c | 1 + src/vnet/session/session.h | 2 ++ src/vnet/session/session_node.c | 11 +++++++---- src/vnet/session/transport.c | 23 ++++++++++++++++------- src/vnet/session/transport_interface.h | 3 +++ src/vnet/tcp/tcp.c | 13 ++++++++++++- src/vnet/tcp/tcp.h | 6 ++++-- src/vnet/tcp/tcp_input.c | 12 +++++------- src/vnet/tcp/tcp_output.c | 2 +- 9 files changed, 51 insertions(+), 22 deletions(-) diff --git a/src/vnet/session/session.c b/src/vnet/session/session.c index 3dd80ad337a..f6894868a3a 100644 --- a/src/vnet/session/session.c +++ b/src/vnet/session/session.c @@ -1366,6 +1366,7 @@ session_manager_main_enable (vlib_main_t * vm) _vec_len (wrk->postponed_event_vector) = 0; wrk->last_vlib_time = vlib_time_now (vlib_mains[i]); + wrk->dispatch_period = 500e-6; if (num_threads > 1) clib_rwlock_init (&smm->wrk[i].peekers_rw_locks); diff --git a/src/vnet/session/session.h b/src/vnet/session/session.h index 131652a8c6e..3bdf6c9d93e 100644 --- a/src/vnet/session/session.h +++ b/src/vnet/session/session.h @@ -229,6 +229,8 @@ typedef struct session_manager_worker_ /** Peekers rw lock */ clib_rwlock_t peekers_rw_locks; + u32 last_tx_packets; + } session_manager_worker_t; struct _session_manager_main diff --git a/src/vnet/session/session_node.c b/src/vnet/session/session_node.c index 34131723665..5ed681d03c7 100644 --- a/src/vnet/session/session_node.c +++ b/src/vnet/session/session_node.c @@ -751,10 +751,12 @@ static void session_update_dispatch_period (session_manager_worker_t * wrk, f64 now, u32 thread_index) { - f64 sample, prev_period = wrk->dispatch_period, a = 0.8; - - sample = now - wrk->last_vlib_time; - wrk->dispatch_period = a * sample + (1 - a) * prev_period; + if (wrk->last_tx_packets > 8) + { + f64 sample = now - wrk->last_vlib_time; + sample = (sample * wrk->last_tx_packets) / VLIB_FRAME_SIZE; + wrk->dispatch_period = (wrk->dispatch_period + sample) * 0.5; + } wrk->last_vlib_time = now; } @@ -917,6 +919,7 @@ session_queue_node_fn (vlib_main_t * vm, vlib_node_runtime_t * node, _vec_len (fifo_events) = 0; wrk->free_event_vector = fifo_events; + wrk->last_tx_packets = n_tx_packets; vlib_node_increment_counter (vm, session_queue_node.index, SESSION_QUEUE_ERROR_TX, n_tx_packets); diff --git a/src/vnet/session/transport.c b/src/vnet/session/transport.c index 0dd9ccd3213..42149eb36a6 100644 --- a/src/vnet/session/transport.c +++ b/src/vnet/session/transport.c @@ -529,23 +529,32 @@ 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 initial_bucket) +transport_connection_tx_pacer_reset (transport_connection_t * tc, + u32 rate_bytes_per_sec, + u32 start_bucket, u64 time_now) { - 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; 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 = initial_bucket; + pacer->bucket = start_bucket; +} + +void +transport_connection_tx_pacer_init (transport_connection_t * tc, + u32 rate_bytes_per_sec, + u32 initial_bucket) +{ + vlib_main_t *vm = vlib_get_main (); + tc->flags |= TRANSPORT_CONNECTION_F_IS_TX_PACED; + transport_connection_tx_pacer_reset (tc, rate_bytes_per_sec, + initial_bucket, + vm->clib_time.last_cpu_time); } void diff --git a/src/vnet/session/transport_interface.h b/src/vnet/session/transport_interface.h index b7aa4b7fa3c..3bfed415874 100644 --- a/src/vnet/session/transport_interface.h +++ b/src/vnet/session/transport_interface.h @@ -102,6 +102,9 @@ transport_tx_fn_type_t transport_protocol_tx_fn_type (transport_proto_t tp); void transport_update_time (f64 time_now, u8 thread_index); void transport_enable_disable (vlib_main_t * vm, u8 is_en); +void transport_connection_tx_pacer_reset (transport_connection_t * tc, + u32 rate_bytes_per_sec, + u32 initial_bucket, u64 time_now); /** * Initialize tx pacer for connection * diff --git a/src/vnet/tcp/tcp.c b/src/vnet/tcp/tcp.c index 1726355f0e3..ba427b76b1a 100644 --- a/src/vnet/tcp/tcp.c +++ b/src/vnet/tcp/tcp.c @@ -1153,7 +1153,7 @@ const static transport_proto_vft_t tcp_proto = { /* *INDENT-ON* */ void -tcp_update_pacer (tcp_connection_t * tc) +tcp_connection_tx_pacer_update (tcp_connection_t * tc) { f64 srtt; @@ -1165,6 +1165,17 @@ tcp_update_pacer (tcp_connection_t * tc) ((f64) tc->cwnd) / srtt); } +void +tcp_connection_tx_pacer_reset (tcp_connection_t * tc, u32 window, + u32 start_bucket) +{ + tcp_worker_ctx_t *wrk = tcp_get_worker (tc->c_thread_index); + u32 byte_rate = window / ((f64) TCP_TICK * tc->srtt); + u64 last_time = wrk->vm->clib_time.last_cpu_time; + transport_connection_tx_pacer_reset (&tc->connection, byte_rate, + start_bucket, last_time); +} + static void tcp_timer_keep_handler (u32 conn_index) { diff --git a/src/vnet/tcp/tcp.h b/src/vnet/tcp/tcp.h index 71af461aca3..bd5e4f71bdb 100644 --- a/src/vnet/tcp/tcp.h +++ b/src/vnet/tcp/tcp.h @@ -735,14 +735,16 @@ void tcp_connection_timers_init (tcp_connection_t * tc); void tcp_connection_timers_reset (tcp_connection_t * tc); void tcp_init_snd_vars (tcp_connection_t * tc); void tcp_connection_init_vars (tcp_connection_t * tc); -void tcp_update_pacer (tcp_connection_t * tc); +void tcp_connection_tx_pacer_update (tcp_connection_t * tc); +void tcp_connection_tx_pacer_reset (tcp_connection_t * tc, u32 window, + u32 start_bucket); always_inline void tcp_cc_rcv_ack (tcp_connection_t * tc) { tc->cc_algo->rcv_ack (tc); tc->tsecr_last_ack = tc->rcv_opts.tsecr; - tcp_update_pacer (tc); + tcp_connection_tx_pacer_update (tc); } always_inline void diff --git a/src/vnet/tcp/tcp_input.c b/src/vnet/tcp/tcp_input.c index af13c5f8215..fb2f1ddc9ef 100644 --- a/src/vnet/tcp/tcp_input.c +++ b/src/vnet/tcp/tcp_input.c @@ -1085,10 +1085,6 @@ tcp_cc_fastrecovery_exit (tcp_connection_t * tc) tcp_fastrecovery_1_smss_off (tc); tcp_fastrecovery_first_off (tc); - /* Update pacer because our cwnd changed. Also makes sure - * that we recompute the max burst size */ - tcp_update_pacer (tc); - TCP_EVT_DBG (TCP_EVT_CC_EVT, tc, 3); } @@ -1290,7 +1286,8 @@ tcp_cc_handle_event (tcp_connection_t * tc, u32 is_dack) } else if (tcp_should_fastrecover (tc)) { - u32 byte_rate; + u32 pacer_wnd; + ASSERT (!tcp_in_fastrecovery (tc)); /* Heuristic to catch potential late dupacks @@ -1319,8 +1316,9 @@ tcp_cc_handle_event (tcp_connection_t * tc, u32 is_dack) tc->cwnd = tc->ssthresh + 3 * tc->snd_mss; } - byte_rate = (0.3 * tc->cwnd) / ((f64) TCP_TICK * tc->srtt); - transport_connection_tx_pacer_init (&tc->connection, byte_rate, 0); + pacer_wnd = clib_max (0.1 * tc->cwnd, 2 * tc->snd_mss); + tcp_connection_tx_pacer_reset (tc, pacer_wnd, + 0 /* start bucket */ ); tcp_program_fastretransmit (tcp_get_worker (tc->c_thread_index), tc); return; diff --git a/src/vnet/tcp/tcp_output.c b/src/vnet/tcp/tcp_output.c index c315c031c97..c135a311fb5 100644 --- a/src/vnet/tcp/tcp_output.c +++ b/src/vnet/tcp/tcp_output.c @@ -1406,7 +1406,7 @@ tcp_rxt_timeout_cc (tcp_connection_t * tc) tc->snd_congestion = tc->snd_una_max; tc->rtt_ts = 0; tc->cwnd_acc_bytes = 0; - + tcp_connection_tx_pacer_reset (tc, tc->cwnd, 2 * tc->snd_mss); tcp_recovery_on (tc); } -- 2.16.6