lacp: create lacp-process on demand

Create lacp-process when the very first slave interface is added to the bond.
Log an event message when lacp-process starts/stops.
Be mindful when lacp-process is signalled to stop.

Type: refactor
Change-Id: I79e10e0a2a385a21a52ae5b8735f24631fdba293
Signed-off-by: Steven Luong <sluong@cisco.com>

src/plugins/lacp/cli.c

@@ -143,11 +143,13 @@ show_lacp (vlib_main_t * vm, u32 * sw_if_indices)
 static void
 show_lacp_details (vlib_main_t * vm, u32 * sw_if_indices)
 {
+  lacp_main_t *lm = &lacp_main;
   slave_if_t *sif;
   lacp_state_struct *state_entry;
   int i;
   f64 now;
 
+  vlib_cli_output (vm, "Number of interfaces: %d", lm->lacp_int);
   if (!sw_if_indices)
     return;
 

src/plugins/lacp/lacp.c

@@ -180,6 +180,7 @@ lacp_interface_enable_disable (vlib_main_t * vm, bond_if_t * bif,
 
   if (enable)
     {
+      lacp_create_periodic_process ();
       port_number = clib_bitmap_first_clear (bif->port_number_bitmap);
       bif->port_number_bitmap = clib_bitmap_set (bif->port_number_bitmap,
 						 port_number, 1);
@@ -195,11 +196,23 @@ lacp_interface_enable_disable (vlib_main_t * vm, bond_if_t * bif,
     }
   else
     {
-      lm->lacp_int--;
+      ASSERT (lm->lacp_int >= 1);
       if (lm->lacp_int == 0)
 	{
-	  vlib_process_signal_event (vm, lm->lacp_process_node_index,
-				     LACP_PROCESS_EVENT_STOP, 0);
+	  /* *INDENT-OFF* */
+	  ELOG_TYPE_DECLARE (e) =
+	    {
+	      .format = "lacp-int-en-dis: BUG lacp_int == 0",
+	    };
+	  /* *INDENT-ON* */
+	  ELOG_DATA (&vlib_global_main.elog_main, e);
+	}
+      else
+	{
+	  lm->lacp_int--;
+	  if (lm->lacp_int == 0)
+	    vlib_process_signal_event (vm, lm->lacp_process_node_index,
+				       LACP_PROCESS_EVENT_STOP, 0);
 	}
     }
 }

src/plugins/lacp/node.c

@@ -25,8 +25,6 @@ lacp_state_struct lacp_state_array[] = {
   {.str = NULL}
 };
 
-static vlib_node_registration_t lacp_process_node;
-
 /** \file
 
     2 x LACP graph nodes: an "interior" node to process
@@ -136,6 +134,46 @@ VLIB_REGISTER_NODE (lacp_input_node, static) = {
 };
 /* *INDENT-ON* */
 
+static void
+lacp_elog_start_event (void)
+{
+  lacp_main_t *lm = &lacp_main;
+  /* *INDENT-OFF* */
+  ELOG_TYPE_DECLARE (e) =
+    {
+      .format = "Starting LACP process, interface count = %d",
+      .format_args = "i4",
+    };
+  /* *INDENT-ON* */
+  struct
+  {
+    u32 count;
+  } *ed;
+
+  ed = ELOG_DATA (&vlib_global_main.elog_main, e);
+  ed->count = lm->lacp_int;
+}
+
+static void
+lacp_elog_stop_event (void)
+{
+  lacp_main_t *lm = &lacp_main;
+  /* *INDENT-OFF* */
+  ELOG_TYPE_DECLARE (e) =
+    {
+      .format = "Stopping LACP process, interface count = %d",
+      .format_args = "i4",
+    };
+  /* *INDENT-ON* */
+  struct
+  {
+    u32 count;
+  } *ed;
+
+  ed = ELOG_DATA (&vlib_global_main.elog_main, e);
+  ed->count = lm->lacp_int;
+}
+
 /*
  * lacp periodic function
  */
@@ -145,10 +183,6 @@ lacp_process (vlib_main_t * vm, vlib_node_runtime_t * rt, vlib_frame_t * f)
   lacp_main_t *lm = &lacp_main;
   f64 poll_time_remaining;
   uword event_type, *event_data = 0;
-  u8 enabled = 0;
-
-  /* So we can send events to the lacp process */
-  lm->lacp_process_node_index = lacp_process_node.index;
 
   ethernet_register_input_type (vm, ETHERNET_TYPE_SLOW_PROTOCOLS /* LACP */ ,
 				lacp_input_node.index);
@@ -156,7 +190,7 @@ lacp_process (vlib_main_t * vm, vlib_node_runtime_t * rt, vlib_frame_t * f)
   poll_time_remaining = 0.2;
   while (1)
     {
-      if (enabled)
+      if (lm->lacp_int > 0)
 	poll_time_remaining =
 	  vlib_process_wait_for_event_or_clock (vm, poll_time_remaining);
       else
@@ -168,17 +202,21 @@ lacp_process (vlib_main_t * vm, vlib_node_runtime_t * rt, vlib_frame_t * f)
 	case ~0:		/* no events => timeout */
 	  break;
 	case LACP_PROCESS_EVENT_START:
-	  enabled = 1;
+	  poll_time_remaining = 0.2;
+	  lacp_elog_start_event ();
 	  break;
 	case LACP_PROCESS_EVENT_STOP:
-	  enabled = 0;
-	  continue;
+	  if (lm->lacp_int == 0)
+	    {
+	      poll_time_remaining = SECS_IN_A_DAY;
+	      lacp_elog_stop_event ();
+	    }
+	  break;
 	default:
 	  clib_warning ("BUG: event type 0x%wx", event_type);
 	  break;
 	}
-      if (event_data)
-	_vec_len (event_data) = 0;
+      vec_reset_length (event_data);
 
       if (vlib_process_suspend_time_is_zero (poll_time_remaining))
 	{
@@ -190,16 +228,20 @@ lacp_process (vlib_main_t * vm, vlib_node_runtime_t * rt, vlib_frame_t * f)
   return 0;
 }
 
-/*
- * lacp periodic node declaration
- */
-/* *INDENT-OFF* */
-VLIB_REGISTER_NODE (lacp_process_node, static) = {
-  .function = lacp_process,
-  .type = VLIB_NODE_TYPE_PROCESS,
-  .name = "lacp-process",
-};
-/* *INDENT-ON* */
+void
+lacp_create_periodic_process (void)
+{
+  lacp_main_t *lm = &lacp_main;
+
+  /* Already created the process node? */
+  if (lm->lacp_process_node_index > 0)
+    return;
+
+  /* No, create it now and make a note of the node index */
+  lm->lacp_process_node_index =
+    vlib_process_create (lm->vlib_main, "lacp-process", lacp_process,
+			 16 /* log2_n_stack_bytes */ );
+}
 
 /*
  * fd.io coding-style-patch-verification: ON

src/plugins/lacp/node.h

@@ -74,6 +74,8 @@ typedef enum
     LACP_N_ERROR,
 } lacp_error_t;
 
+#define SECS_IN_A_DAY 86400.0
+
 /* lacp packet trace capture */
 typedef struct
 {
@@ -129,7 +131,7 @@ typedef struct
   vlib_packet_template_t marker_packet_templates[MARKER_N_PACKET_TEMPLATES];
 
   /* LACP interface count */
-  u32 lacp_int;
+  volatile u32 lacp_int;
 
   /* debug is on or off */
   u8 debug;
@@ -138,6 +140,7 @@ typedef struct
 extern lacp_state_struct lacp_state_array[];
 extern lacp_main_t lacp_main;
 
+void lacp_create_periodic_process (void);
 clib_error_t *lacp_plugin_api_hookup (vlib_main_t * vm);
 int lacp_dump_ifs (lacp_interface_details_t ** out_bondids);
 lacp_error_t lacp_input (vlib_main_t * vm, vlib_buffer_t * b0, u32 bi0);