4 files changed, 30 insertions, 63 deletions

diff --git a/src/vnet/tcp/tcp.c b/src/vnet/tcp/tcp.c
index c0b50ce6962..86729011f8f 100644
--- a/src/vnet/tcp/tcp.c
+++ b/src/vnet/tcp/tcp.c
@@ -1396,8 +1396,11 @@ tcp_connection_tx_pacer_update (tcp_connection_t * tc)
   if (!transport_connection_is_tx_paced (&tc->connection))
     return;
 
+  f64 srtt = clib_min ((f64) tc->srtt * TCP_TICK, tc->mrtt_us);
+
   transport_connection_tx_pacer_update (&tc->connection,
-					tcp_cc_get_pacing_rate (tc));
+					tcp_cc_get_pacing_rate (tc),
+					srtt * CLIB_US_TIME_FREQ);
 }
 
 void
@@ -1406,7 +1409,8 @@ tcp_connection_tx_pacer_reset (tcp_connection_t * tc, u32 window,
 {
   f64 srtt = clib_min ((f64) tc->srtt * TCP_TICK, tc->mrtt_us);
   u64 rate = (u64) window / srtt;
-  transport_connection_tx_pacer_reset (&tc->connection, rate, start_bucket);
+  transport_connection_tx_pacer_reset (&tc->connection, rate, start_bucket,
+				       srtt * CLIB_US_TIME_FREQ);
 }
 
 static void
diff --git a/src/vnet/tcp/tcp.h b/src/vnet/tcp/tcp.h
index 7dd88bf0a49..e9247eb86b2 100644
--- a/src/vnet/tcp/tcp.h
+++ b/src/vnet/tcp/tcp.h
@@ -394,7 +394,6 @@ typedef struct _tcp_connection
   u32 prr_start;	/**< snd_una when prr starts */
   u32 rxt_delivered;	/**< Rxt bytes delivered during current cc event */
   u32 rxt_head;		/**< snd_una last time we re rxted the head */
-  u32 prev_dsegs_out;	/**< Number of dsegs after last ack */
   u32 tsecr_last_ack;	/**< Timestamp echoed to us in last healthy ACK */
   u32 snd_congestion;	/**< snd_una_max when congestion is detected */
   u32 tx_fifo_size;	/**< Tx fifo size. Used to constrain cwnd */
diff --git a/src/vnet/tcp/tcp_input.c b/src/vnet/tcp/tcp_input.c
index 172dcd2ee6f..c94e5babc50 100755
--- a/src/vnet/tcp/tcp_input.c
+++ b/src/vnet/tcp/tcp_input.c
@@ -575,21 +575,6 @@ tcp_estimate_initial_rtt (tcp_connection_t * tc)
   tcp_update_rto (tc);
 }
 
-always_inline u8
-tcp_recovery_no_snd_space (tcp_connection_t * tc)
-{
-  u32 space;
-
-  ASSERT (tcp_in_cong_recovery (tc));
-
-  if (tcp_in_recovery (tc))
-    space = tcp_available_output_snd_space (tc);
-  else
-    space = tcp_fastrecovery_prr_snd_space (tc);
-
-  return (space < tc->snd_mss + tc->burst_acked);
-}
-
 /**
  * Dequeue bytes for connections that have received acks in last burst
  */
@@ -610,33 +595,26 @@ 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 (tc->burst_acked)
-	{
-	  /* Dequeue the newly ACKed bytes */
-	  session_tx_fifo_dequeue_drop (&tc->connection, tc->burst_acked);
-	  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->burst_acked))
+	continue;
 
-	  /* If everything has been acked, stop retransmit timer
-	   * otherwise update. */
-	  tcp_retransmit_timer_update (tc);
+      /* Dequeue the newly ACKed bytes */
+      session_tx_fifo_dequeue_drop (&tc->connection, tc->burst_acked);
+      tcp_validate_txf_size (tc, tc->snd_una_max - tc->snd_una);
 
-	  /* Update pacer based on our new cwnd estimate */
-	  tcp_connection_tx_pacer_update (tc);
+      if (PREDICT_FALSE (tc->flags & TCP_CONN_PSH_PENDING))
+	{
+	  if (seq_leq (tc->psh_seq, tc->snd_una))
+	    tc->flags &= ~TCP_CONN_PSH_PENDING;
 	}
 
-      /* 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_in_cong_recovery (tc) && tcp_recovery_no_snd_space (tc)))
-	transport_connection_tx_pacer_reset_bucket (&tc->connection);
+      /* 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);
 
-      tc->prev_dsegs_out = tc->data_segs_out;
       tc->burst_acked = 0;
     }
   _vec_len (wrk->pending_deq_acked) = 0;
@@ -1623,10 +1601,11 @@ process_ack:
   if (tc->cfg_flags & TCP_CFG_F_RATE_SAMPLE)
     tcp_bt_sample_delivery_rate (tc, &rs);
 
-  tcp_program_dequeue (wrk, tc);
-
   if (tc->bytes_acked)
-    tcp_update_rtt (tc, &rs, vnet_buffer (b)->tcp.ack_number);
+    {
+      tcp_program_dequeue (wrk, tc);
+      tcp_update_rtt (tc, &rs, vnet_buffer (b)->tcp.ack_number);
+    }
 
   TCP_EVT (TCP_EVT_ACK_RCVD, tc);
 
diff --git a/src/vnet/tcp/tcp_output.c b/src/vnet/tcp/tcp_output.c
index 64e3b1a584a..c06bbf19ef4 100644
--- a/src/vnet/tcp/tcp_output.c
+++ b/src/vnet/tcp/tcp_output.c
@@ -411,7 +411,7 @@ tcp_update_burst_snd_vars (tcp_connection_t * tc)
   if (tc->snd_una == tc->snd_nxt)
     {
       tcp_cc_event (tc, TCP_CC_EVT_START_TX);
-      tcp_connection_tx_pacer_reset (tc, tc->cwnd, TRANSPORT_PACER_MIN_MSS);
+      tcp_connection_tx_pacer_reset (tc, tc->cwnd, TRANSPORT_PACER_MIN_BURST);
     }
 }
 
@@ -1875,9 +1875,9 @@ static int
 tcp_retransmit_sack (tcp_worker_ctx_t * wrk, tcp_connection_t * tc,
 		     u32 burst_size)
 {
-  u8 snd_limited = 0, can_rescue = 0, reset_pacer = 0;
   u32 n_written = 0, offset, max_bytes, n_segs = 0;
-  u32 bi, max_deq, burst_bytes, sent_bytes;
+  u8 snd_limited = 0, can_rescue = 0;
+  u32 bi, max_deq, burst_bytes;
   sack_scoreboard_hole_t *hole;
   vlib_main_t *vm = wrk->vm;
   vlib_buffer_t *b = 0;
@@ -1900,12 +1900,7 @@ tcp_retransmit_sack (tcp_worker_ctx_t * wrk, tcp_connection_t * tc,
     snd_space = tcp_fastrecovery_prr_snd_space (tc);
 
   if (snd_space < tc->snd_mss)
-    {
-      reset_pacer = burst_bytes > tc->snd_mss;
-      goto done;
-    }
-
-  reset_pacer = snd_space < burst_bytes;
+    goto done;
 
   sb = &tc->sack_sb;
 
@@ -2021,17 +2016,7 @@ tcp_retransmit_sack (tcp_worker_ctx_t * wrk, tcp_connection_t * tc,
 
 done:
 
-  if (reset_pacer)
-    {
-      transport_connection_tx_pacer_reset_bucket (&tc->connection);
-    }
-  else
-    {
-      sent_bytes = clib_min (n_segs * tc->snd_mss, burst_bytes);
-      transport_connection_tx_pacer_update_bytes (&tc->connection,
-						  sent_bytes);
-    }
-
+  transport_connection_tx_pacer_reset_bucket (&tc->connection, 0);
   return n_segs;
 }