session: avoid scanning new io list under load

Type: fix

Signed-off-by: Florin Coras <fcoras@cisco.com>
Change-Id: Idaa7cc26ad941be86daec4ed5920727237712f4a

2 files changed, 51 insertions, 21 deletions

diff --git a/src/vnet/session/session_cli.c b/src/vnet/session/session_cli.c
index 4d4141da375..aba1c610e18 100644
--- a/src/vnet/session/session_cli.c
+++ b/src/vnet/session/session_cli.c
@@ -439,6 +439,39 @@ session_cli_show_session_filter (vlib_main_t * vm, u32 thread_index,
 		     count);
 }
 
+void
+session_cli_show_events_thread (vlib_main_t * vm, u32 thread_index)
+{
+  session_worker_t *wrk;
+
+  wrk = session_main_get_worker_if_valid (thread_index);
+  if (!wrk)
+    {
+      vlib_cli_output (vm, "invalid thread index %u", thread_index);
+      return;
+    }
+
+  vlib_cli_output (vm, "Thread %d:\n", thread_index);
+  vlib_cli_output (vm, " evt elements alloc: %u",
+		   pool_elts (wrk->event_elts));
+  vlib_cli_output (vm, " ctrl evt elt data alloc: %d",
+		   pool_elts (wrk->ctrl_evts_data));
+}
+
+static void
+session_cli_show_events (vlib_main_t * vm, u32 thread_index)
+{
+  session_main_t *smm = &session_main;
+  if (!thread_index)
+    {
+      session_cli_show_events_thread (vm, thread_index);
+      return;
+    }
+
+  for (thread_index = 0; thread_index < vec_len (smm->wrk); thread_index++)
+    session_cli_show_events_thread (vm, thread_index);
+}
+
 static void
 session_cli_print_transport_protos (vlib_main_t * vm)
 {
@@ -469,6 +502,7 @@ show_session_command_fn (vlib_main_t * vm, unformat_input_t * input,
   app_worker_t *app_wrk;
   u32 transport_index;
   const u8 *app_name;
+  u8 do_events = 0;
   int verbose = 0;
   session_t *s;
 
@@ -559,6 +593,8 @@ show_session_command_fn (vlib_main_t * vm, unformat_input_t * input,
 	  session_cli_print_session_states (vm);
 	  goto done;
 	}
+      else if (unformat (line_input, "events"))
+	do_events = 1;
       else
 	{
 	  error = clib_error_return (0, "unknown input `%U'",
@@ -607,6 +643,12 @@ show_session_command_fn (vlib_main_t * vm, unformat_input_t * input,
       goto done;
     }
 
+  if (do_events)
+    {
+      session_cli_show_events (vm, thread_index);
+      goto done;
+    }
+
   if (do_filter)
     {
       if (end < start)
diff --git a/src/vnet/session/session_node.c b/src/vnet/session/session_node.c
index bc22cc0a98c..c3570791898 100644
--- a/src/vnet/session/session_node.c
+++ b/src/vnet/session/session_node.c
@@ -1257,8 +1257,8 @@ session_queue_node_fn (vlib_main_t * vm, vlib_node_runtime_t * node,
   u32 thread_index = vm->thread_index, n_to_dequeue;
   session_worker_t *wrk = &smm->wrk[thread_index];
   session_evt_elt_t *elt, *ctrl_he, *new_he, *old_he;
+  clib_llist_index_t ei, next_ei, old_ti;
   svm_msg_q_msg_t _msg, *msg = &_msg;
-  clib_llist_index_t old_ti;
   int i, n_tx_packets = 0;
   session_event_t *evt;
   svm_msg_q_t *mq;
@@ -1314,24 +1314,14 @@ session_queue_node_fn (vlib_main_t * vm, vlib_node_runtime_t * node,
   old_he = pool_elt_at_index (wrk->event_elts, wrk->old_head);
   old_ti = clib_llist_prev_index (old_he, evt_list);
 
-  /* *INDENT-OFF* */
-  clib_llist_foreach_safe (wrk->event_elts, evt_list, new_he, elt, ({
-    session_evt_type_t et;
-
-    et = elt->evt.event_type;
-    clib_llist_remove (wrk->event_elts, evt_list, elt);
-
-    /* Postpone tx events if we can't handle them this dispatch cycle */
-    if (n_tx_packets >= VLIB_FRAME_SIZE
-	&& (et == SESSION_IO_EVT_TX || et == SESSION_IO_EVT_TX_FLUSH))
-      {
-	clib_llist_add (wrk->event_elts, evt_list, elt, new_he);
-	continue;
-      }
-
-    session_event_dispatch_io (wrk, node, elt, thread_index, &n_tx_packets);
-  }));
-  /* *INDENT-ON* */
+  ei = clib_llist_next_index (new_he, evt_list);
+  while (ei != wrk->new_head && n_tx_packets < VLIB_FRAME_SIZE)
+    {
+      elt = pool_elt_at_index (wrk->event_elts, ei);
+      ei = clib_llist_next_index (elt, evt_list);
+      clib_llist_remove (wrk->event_elts, evt_list, elt);
+      session_event_dispatch_io (wrk, node, elt, thread_index, &n_tx_packets);
+    }
 
   /*
    * Handle the old io events, if we had any prior to processing the new ones
@@ -1339,8 +1329,6 @@ session_queue_node_fn (vlib_main_t * vm, vlib_node_runtime_t * node,
 
   if (old_ti != wrk->old_head)
     {
-      clib_llist_index_t ei, next_ei;
-
       old_he = pool_elt_at_index (wrk->event_elts, wrk->old_head);
       ei = clib_llist_next_index (old_he, evt_list);