session: pass tx buffers in bulk to transports

Type: improvement

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

3 files changed, 12 insertions, 8 deletions

diff --git a/src/vnet/session/session.h b/src/vnet/session/session.h
index e549da588e9..9d6c945bb4d 100644
--- a/src/vnet/session/session.h
+++ b/src/vnet/session/session.h
@@ -59,6 +59,7 @@ typedef struct session_tx_context_
 
   /** Vector of tx buffer free lists */
   u32 *tx_buffers;
+  vlib_buffer_t **transport_pending_bufs;
 } session_tx_context_t;
 
 typedef struct session_evt_elt
diff --git a/src/vnet/session/session_node.c b/src/vnet/session/session_node.c
index bebabd3d68e..403c28f28ce 100644
--- a/src/vnet/session/session_node.c
+++ b/src/vnet/session/session_node.c
@@ -1319,6 +1319,8 @@ session_tx_fifo_read_and_snd_i (session_worker_t * wrk,
   ctx->left_to_snd = ctx->max_len_to_snd;
   n_left = ctx->n_segs_per_evt;
 
+  vec_validate (ctx->transport_pending_bufs, n_left);
+
   while (n_left >= 4)
     {
       vlib_buffer_t *b0, *b1;
@@ -1340,9 +1342,8 @@ session_tx_fifo_read_and_snd_i (session_worker_t * wrk,
       session_tx_fill_buffer (vm, ctx, b0, &n_bufs, peek_data);
       session_tx_fill_buffer (vm, ctx, b1, &n_bufs, peek_data);
 
-      ctx->transport_vft->push_header (ctx->tc, b0);
-      ctx->transport_vft->push_header (ctx->tc, b1);
-
+      ctx->transport_pending_bufs[ctx->n_segs_per_evt - n_left] = b0;
+      ctx->transport_pending_bufs[ctx->n_segs_per_evt - n_left + 1] = b1;
       n_left -= 2;
 
       vec_add1 (wrk->pending_tx_buffers, bi0);
@@ -1366,16 +1367,17 @@ session_tx_fifo_read_and_snd_i (session_worker_t * wrk,
       b0 = vlib_get_buffer (vm, bi0);
       session_tx_fill_buffer (vm, ctx, b0, &n_bufs, peek_data);
 
-      /* Ask transport to push header after current_length and
-       * total_length_not_including_first_buffer are updated */
-      ctx->transport_vft->push_header (ctx->tc, b0);
-
+      ctx->transport_pending_bufs[ctx->n_segs_per_evt - n_left] = b0;
       n_left -= 1;
 
       vec_add1 (wrk->pending_tx_buffers, bi0);
       vec_add1 (wrk->pending_tx_nexts, next_index);
     }
 
+  /* Ask transport to push headers */
+  ctx->transport_vft->push_header (ctx->tc, ctx->transport_pending_bufs,
+				   ctx->n_segs_per_evt);
+
   if (PREDICT_FALSE ((n_trace = vlib_get_trace_count (vm, node)) > 0))
     session_tx_trace_frame (vm, node, next_index, wrk->pending_tx_buffers,
 			    ctx->n_segs_per_evt, ctx->s, n_trace);
diff --git a/src/vnet/session/transport.h b/src/vnet/session/transport.h
index 549f17957cc..4edc281ff9c 100644
--- a/src/vnet/session/transport.h
+++ b/src/vnet/session/transport.h
@@ -85,7 +85,8 @@ typedef struct _transport_proto_vft
    * Transmission
    */
 
-  u32 (*push_header) (transport_connection_t * tconn, vlib_buffer_t * b);
+  u32 (*push_header) (transport_connection_t *tconn, vlib_buffer_t **b,
+		      u32 n_bufs);
   int (*send_params) (transport_connection_t * tconn,
 		      transport_send_params_t *sp);
   void (*update_time) (f64 time_now, u8 thread_index);