session: pass tx buffers in bulk to transports

Type: improvement

Signed-off-by: Florin Coras <fcoras@cisco.com>
Change-Id: I1025cccd784f80b557847f69c3ea1ada5c9de60d

2 files changed, 35 insertions, 6 deletions

diff --git a/src/vnet/tcp/tcp.h b/src/vnet/tcp/tcp.h
index 710561fb24a..c5dd3172302 100644
--- a/src/vnet/tcp/tcp.h
+++ b/src/vnet/tcp/tcp.h
@@ -313,8 +313,8 @@ u32 tcp_snd_space (tcp_connection_t * tc);
 int tcp_fastrecovery_prr_snd_space (tcp_connection_t * tc);
 void tcp_reschedule (tcp_connection_t * tc);
 fib_node_index_t tcp_lookup_rmt_in_fib (tcp_connection_t * tc);
-u32 tcp_session_push_header (transport_connection_t * tconn,
-			     vlib_buffer_t * b);
+u32 tcp_session_push_header (transport_connection_t *tconn, vlib_buffer_t **b,
+			     u32 n_bufs);
 int tcp_session_custom_tx (void *conn, transport_send_params_t * sp);
 
 void tcp_connection_timers_init (tcp_connection_t * tc);
diff --git a/src/vnet/tcp/tcp_output.c b/src/vnet/tcp/tcp_output.c
index 55fa6d1b5d8..88cd91330b0 100644
--- a/src/vnet/tcp/tcp_output.c
+++ b/src/vnet/tcp/tcp_output.c
@@ -963,11 +963,9 @@ tcp_buffer_len (vlib_buffer_t * b)
   return data_len;
 }
 
-u32
-tcp_session_push_header (transport_connection_t * tconn, vlib_buffer_t * b)
+always_inline u32
+tcp_push_one_header (tcp_connection_t *tc, vlib_buffer_t *b)
 {
-  tcp_connection_t *tc = (tcp_connection_t *) tconn;
-
   if (tc->cfg_flags & TCP_CFG_F_RATE_SAMPLE)
     tcp_bt_track_tx (tc, tcp_buffer_len (b));
 
@@ -975,6 +973,37 @@ tcp_session_push_header (transport_connection_t * tconn, vlib_buffer_t * b)
 		  /* update_snd_nxt */ 1);
 
   tcp_validate_txf_size (tc, tc->snd_nxt - tc->snd_una);
+  return 0;
+}
+
+u32
+tcp_session_push_header (transport_connection_t *tconn, vlib_buffer_t **bs,
+			 u32 n_bufs)
+{
+  tcp_connection_t *tc = (tcp_connection_t *) tconn;
+
+  while (n_bufs >= 4)
+    {
+      vlib_prefetch_buffer_header (bs[2], STORE);
+      vlib_prefetch_buffer_header (bs[3], STORE);
+
+      tcp_push_one_header (tc, bs[0]);
+      tcp_push_one_header (tc, bs[1]);
+
+      n_bufs -= 2;
+      bs += 2;
+    }
+  while (n_bufs)
+    {
+      if (n_bufs > 1)
+	vlib_prefetch_buffer_header (bs[1], STORE);
+
+      tcp_push_one_header (tc, bs[0]);
+
+      n_bufs -= 1;
+      bs += 1;
+    }
+
   /* If not tracking an ACK, start tracking */
   if (tc->rtt_ts == 0 && !tcp_in_cong_recovery (tc))
     {