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authorFlorin Coras <fcoras@cisco.com>2019-10-06 14:06:14 -0700
committerFlorin Coras <florin.coras@gmail.com>2019-10-10 21:23:14 +0000
commitc31dc31f84961033ecb6354811e0c360b6cf5f79 (patch)
tree46224d5f2b9d126cb6bd5fa289a18186cb172aa5 /src/vnet/tcp/tcp_input.c
parent71a5da0c8dfa12ff012c8c101cf4d2b29fa0b6e3 (diff)
tcp: improve pacing after idle send periods
Rest pacer on ack reception if we haven't recently sent anything. Type: feature Change-Id: I820bacd81b65130052dfafbfcbe6ca4553069fbc Signed-off-by: Florin Coras <fcoras@cisco.com>
Diffstat (limited to 'src/vnet/tcp/tcp_input.c')
-rwxr-xr-xsrc/vnet/tcp/tcp_input.c61
1 files changed, 39 insertions, 22 deletions
diff --git a/src/vnet/tcp/tcp_input.c b/src/vnet/tcp/tcp_input.c
index f177f5f4753..ea64e4ab754 100755
--- a/src/vnet/tcp/tcp_input.c
+++ b/src/vnet/tcp/tcp_input.c
@@ -574,6 +574,15 @@ tcp_estimate_initial_rtt (tcp_connection_t * tc)
tcp_update_rto (tc);
}
+always_inline u8
+tcp_recovery_no_snd_space (tcp_connection_t * tc)
+{
+ return (tcp_in_fastrecovery (tc)
+ && tcp_fastrecovery_prr_snd_space (tc) < tc->snd_mss)
+ || (tcp_in_recovery (tc)
+ && tcp_available_output_snd_space (tc) < tc->snd_mss);
+}
+
/**
* Dequeue bytes for connections that have received acks in last burst
*/
@@ -594,26 +603,35 @@ tcp_handle_postponed_dequeues (tcp_worker_ctx_t * wrk)
tc = tcp_connection_get (pending_deq_acked[i], thread_index);
tc->flags &= ~TCP_CONN_DEQ_PENDING;
- if (PREDICT_FALSE (!tc->burst_acked))
- continue;
+ if (tc->burst_acked)
+ {
+ /* Dequeue the newly ACKed bytes */
+ session_tx_fifo_dequeue_drop (&tc->connection, tc->burst_acked);
+ tc->burst_acked = 0;
+ tcp_validate_txf_size (tc, tc->snd_una_max - tc->snd_una);
- /* Dequeue the newly ACKed bytes */
- session_tx_fifo_dequeue_drop (&tc->connection, tc->burst_acked);
- tc->burst_acked = 0;
- tcp_validate_txf_size (tc, tc->snd_una_max - tc->snd_una);
+ if (PREDICT_FALSE (tc->flags & TCP_CONN_PSH_PENDING))
+ {
+ if (seq_leq (tc->psh_seq, tc->snd_una))
+ tc->flags &= ~TCP_CONN_PSH_PENDING;
+ }
- if (PREDICT_FALSE (tc->flags & TCP_CONN_PSH_PENDING))
- {
- if (seq_leq (tc->psh_seq, tc->snd_una))
- tc->flags &= ~TCP_CONN_PSH_PENDING;
- }
+ /* If everything has been acked, stop retransmit timer
+ * otherwise update. */
+ tcp_retransmit_timer_update (tc);
- /* If everything has been acked, stop retransmit timer
- * otherwise update. */
- tcp_retransmit_timer_update (tc);
+ /* Update pacer based on our new cwnd estimate */
+ tcp_connection_tx_pacer_update (tc);
+ }
- /* Update pacer based on our new cwnd estimate */
- tcp_connection_tx_pacer_update (tc);
+ /* Reset the pacer if we've been idle, i.e., no data sent or if
+ * we're in recovery and snd space constrained */
+ if (tc->data_segs_out == tc->prev_dsegs_out
+ || tcp_recovery_no_snd_space (tc))
+ transport_connection_tx_pacer_reset_bucket (&tc->connection,
+ wrk->vm->clib_time.
+ last_cpu_time);
+ tc->prev_dsegs_out = tc->data_segs_out;
}
_vec_len (wrk->pending_deq_acked) = 0;
}
@@ -1335,6 +1353,8 @@ tcp_cc_recover (tcp_connection_t * tc)
tc->rtt_ts = 0;
tc->flags &= ~TCP_CONN_RXT_PENDING;
+ tcp_connection_tx_pacer_reset (tc, tc->cwnd, 0 /* start bucket */ );
+
/* Previous recovery left us congested. Continue sending as part
* of the current recovery event with an updated snd_congestion */
if (tc->sack_sb.sacked_bytes)
@@ -1354,8 +1374,6 @@ tcp_cc_recover (tcp_connection_t * tc)
if (!tcp_in_recovery (tc) && !is_spurious)
tcp_cc_recovered (tc);
- tcp_connection_tx_pacer_reset (tc, tc->cwnd, 0 /* start bucket */ );
-
tcp_fastrecovery_off (tc);
tcp_fastrecovery_first_off (tc);
tcp_recovery_off (tc);
@@ -1589,11 +1607,10 @@ process_ack:
if (tc->flags & TCP_CONN_RATE_SAMPLE)
tcp_bt_sample_delivery_rate (tc, &rs);
+ tcp_program_dequeue (wrk, tc);
+
if (tc->bytes_acked)
- {
- tcp_program_dequeue (wrk, tc);
- tcp_update_rtt (tc, &rs, vnet_buffer (b)->tcp.ack_number);
- }
+ tcp_update_rtt (tc, &rs, vnet_buffer (b)->tcp.ack_number);
TCP_EVT (TCP_EVT_ACK_RCVD, tc);