8 files changed, 93 insertions, 9 deletions

diff --git a/src/vnet/session/application.c b/src/vnet/session/application.c
index 0dcb3e6ad94..7777c7275b3 100644
--- a/src/vnet/session/application.c
+++ b/src/vnet/session/application.c
@@ -550,6 +550,8 @@ application_alloc_and_init (app_init_args_t * a)
     props->use_mq_eventfd = 1;
   if (options[APP_OPTIONS_TLS_ENGINE])
     app->tls_engine = options[APP_OPTIONS_TLS_ENGINE];
+  if (options[APP_OPTIONS_MAX_FIFO_SIZE])
+    props->max_fifo_size = options[APP_OPTIONS_MAX_FIFO_SIZE];
   if (options[APP_OPTIONS_HIGH_WATERMARK])
     props->high_watermark = options[APP_OPTIONS_HIGH_WATERMARK];
   if (options[APP_OPTIONS_LOW_WATERMARK])
diff --git a/src/vnet/session/application.h b/src/vnet/session/application.h
index 9943576377d..90b5a5a277e 100644
--- a/src/vnet/session/application.h
+++ b/src/vnet/session/application.h
@@ -261,6 +261,9 @@ int app_worker_migrate_notify (app_worker_t * app_wrk, session_t * s,
 			       session_handle_t new_sh);
 int app_worker_builtin_rx (app_worker_t * app_wrk, session_t * s);
 int app_worker_builtin_tx (app_worker_t * app_wrk, session_t * s);
+int app_worker_session_fifo_tuning (app_worker_t * app_wrk, session_t * s,
+				    svm_fifo_t * f,
+				    session_ft_action_t act, u32 len);
 segment_manager_t *app_worker_get_listen_segment_manager (app_worker_t *,
 							  session_t *);
 segment_manager_t *app_worker_get_connect_segment_manager (app_worker_t *);
diff --git a/src/vnet/session/application_interface.h b/src/vnet/session/application_interface.h
index d03994fc1f9..2ecabb03204 100644
--- a/src/vnet/session/application_interface.h
+++ b/src/vnet/session/application_interface.h
@@ -68,6 +68,10 @@ typedef struct session_cb_vft_
   /** Cert and key pair delete notification */
   int (*app_cert_key_pair_delete_callback) (app_cert_key_pair_t * ckpair);
 
+  /** Delegate fifo-tuning-logic to application */
+  int (*fifo_tuning_callback) (session_t * s, svm_fifo_t * f,
+			       session_ft_action_t act, u32 bytes);
+
 } session_cb_vft_t;
 
 #define foreach_app_init_args			\
@@ -201,6 +205,7 @@ typedef enum
   APP_OPTIONS_PROXY_TRANSPORT,
   APP_OPTIONS_ACCEPT_COOKIE,
   APP_OPTIONS_TLS_ENGINE,
+  APP_OPTIONS_MAX_FIFO_SIZE,
   APP_OPTIONS_HIGH_WATERMARK,
   APP_OPTIONS_LOW_WATERMARK,
   APP_OPTIONS_N_OPTIONS
diff --git a/src/vnet/session/application_worker.c b/src/vnet/session/application_worker.c
index 0b67d2922bf..1793998f1e0 100644
--- a/src/vnet/session/application_worker.c
+++ b/src/vnet/session/application_worker.c
@@ -275,11 +275,16 @@ app_worker_init_accepted (session_t * s)
   app_worker_t *app_wrk;
   segment_manager_t *sm;
   session_t *listener;
+  application_t *app;
 
   listener = listen_session_get_from_handle (s->listener_handle);
   app_wrk = application_listener_select_worker (listener);
   s->app_wrk_index = app_wrk->wrk_index;
 
+  app = application_get (app_wrk->app_index);
+  if (app->cb_fns.fifo_tuning_callback)
+    s->flags |= SESSION_F_CUSTOM_FIFO_TUNING;
+
   sm = app_worker_get_listen_segment_manager (app_wrk, listener);
   if (app_worker_alloc_session_fifos (sm, s))
     return -1;
@@ -307,6 +312,10 @@ app_worker_init_connected (app_worker_t * app_wrk, session_t * s)
       if (app_worker_alloc_session_fifos (sm, s))
 	return -1;
     }
+
+  if (app->cb_fns.fifo_tuning_callback)
+    s->flags |= SESSION_F_CUSTOM_FIFO_TUNING;
+
   return 0;
 }
 
@@ -433,6 +442,15 @@ app_worker_connect_session (app_worker_t * app, session_endpoint_t * sep,
 }
 
 int
+app_worker_session_fifo_tuning (app_worker_t * app_wrk, session_t * s,
+				svm_fifo_t * f,
+				session_ft_action_t act, u32 len)
+{
+  application_t *app = application_get (app_wrk->app_index);
+  return app->cb_fns.fifo_tuning_callback (s, f, act, len);
+}
+
+int
 app_worker_alloc_connects_segment_manager (app_worker_t * app_wrk)
 {
   segment_manager_t *sm;
diff --git a/src/vnet/session/segment_manager.c b/src/vnet/session/segment_manager.c
index 25fbd6f2c04..eb3f63c9a6c 100644
--- a/src/vnet/session/segment_manager.c
+++ b/src/vnet/session/segment_manager.c
@@ -26,11 +26,12 @@ typedef struct segment_manager_main_
   /*
    * Configuration
    */
-  u32 default_fifo_size;		/**< default rx/tx fifo size */
-  u32 default_segment_size;		/**< default fifo segment size */
-  u32 default_app_mq_size;		/**< default app msg q size */
-  u8 default_high_watermark;		/**< default high watermark % */
-  u8 default_low_watermark;		/**< default low watermark % */
+  u32 default_fifo_size;	/**< default rx/tx fifo size */
+  u32 default_segment_size;	/**< default fifo segment size */
+  u32 default_app_mq_size;	/**< default app msg q size */
+  u32 default_max_fifo_size;	/**< default max fifo size */
+  u8 default_high_watermark;	/**< default high watermark % */
+  u8 default_low_watermark;	/**< default low watermark % */
 } segment_manager_main_t;
 
 static segment_manager_main_t sm_main;
@@ -56,6 +57,7 @@ segment_manager_props_init (segment_manager_props_t * props)
   props->rx_fifo_size = sm_main.default_fifo_size;
   props->tx_fifo_size = sm_main.default_fifo_size;
   props->evt_q_size = sm_main.default_app_mq_size;
+  props->max_fifo_size = sm_main.default_max_fifo_size;
   props->high_watermark = sm_main.default_high_watermark;
   props->low_watermark = sm_main.default_low_watermark;
   props->n_slices = vlib_num_workers () + 1;
@@ -335,6 +337,10 @@ segment_manager_init (segment_manager_t * sm)
 			     sm_main.default_segment_size);
   prealloc_fifo_pairs = props->prealloc_fifos;
 
+  sm->max_fifo_size = props->max_fifo_size ?
+    props->max_fifo_size : sm_main.default_max_fifo_size;
+  sm->max_fifo_size = clib_max (sm->max_fifo_size, 4096);
+
   segment_manager_set_watermarks (sm,
 				  props->high_watermark,
 				  props->low_watermark);
@@ -832,6 +838,7 @@ segment_manager_main_init (segment_manager_main_init_args_t * a)
   sm->default_fifo_size = 1 << 12;
   sm->default_segment_size = 1 << 20;
   sm->default_app_mq_size = 128;
+  sm->default_max_fifo_size = 4 << 20;
   sm->default_high_watermark = 80;
   sm->default_low_watermark = 50;
 }
@@ -844,6 +851,9 @@ segment_manager_show_fn (vlib_main_t * vm, unformat_input_t * input,
   u8 show_segments = 0, verbose = 0;
   segment_manager_t *sm;
   fifo_segment_t *seg;
+  app_worker_t *app_wrk;
+  application_t *app;
+  u8 custom_logic;
 
   while (unformat_check_input (input) != UNFORMAT_END_OF_INPUT)
     {
@@ -859,13 +869,22 @@ segment_manager_show_fn (vlib_main_t * vm, unformat_input_t * input,
 		   pool_elts (smm->segment_managers));
   if (verbose && pool_elts (smm->segment_managers))
     {
-      vlib_cli_output (vm, "%-10s%=15s%=12s", "Index", "App Index",
-		       "Segments");
+      vlib_cli_output (vm, "%-6s%=10s%=10s%=13s%=11s%=11s%=12s",
+		       "Index", "AppIndex", "Segments", "MaxFifoSize",
+		       "HighWater", "LowWater", "FifoTuning");
 
       /* *INDENT-OFF* */
       pool_foreach (sm, smm->segment_managers, ({
-	vlib_cli_output (vm, "%-10d%=15d%=12d", segment_manager_index (sm),
-			   sm->app_wrk_index, pool_elts (sm->segments));
+        app_wrk = app_worker_get_if_valid (sm->app_wrk_index);
+        app = app_wrk ? application_get (app_wrk->app_index) : 0;
+        custom_logic = (app && (app->cb_fns.fifo_tuning_callback)) ? 1 : 0;
+
+	vlib_cli_output (vm, "%-6d%=10d%=10d%=13U%=11d%=11d%=12s",
+                         segment_manager_index (sm),
+			 sm->app_wrk_index, pool_elts (sm->segments),
+                         format_memory_size, sm->max_fifo_size,
+                         sm->high_watermark, sm->low_watermark,
+                         custom_logic ? "custom" : "none");
       }));
       /* *INDENT-ON* */
 
diff --git a/src/vnet/session/segment_manager.h b/src/vnet/session/segment_manager.h
index cad95509b2e..688711a3312 100644
--- a/src/vnet/session/segment_manager.h
+++ b/src/vnet/session/segment_manager.h
@@ -19,6 +19,7 @@
 #include <vppinfra/lock.h>
 #include <vppinfra/valloc.h>
 #include <svm/fifo_segment.h>
+#include <vnet/session/session_types.h>
 
 typedef struct _segment_manager_props
 {
@@ -34,6 +35,7 @@ typedef struct _segment_manager_props
   u8 n_slices;				/**< number of fs slices/threads */
   ssvm_segment_type_t segment_type;	/**< seg type: if set to SSVM_N_TYPES,
 					     private segments are used */
+  u32 max_fifo_size;			/**< max fifo size */
   u8 high_watermark;			/**< memory usage high watermark % */
   u8 low_watermark;			/**< memory usage low watermark % */
 } segment_manager_props_t;
@@ -61,6 +63,7 @@ typedef struct _segment_manager
    */
   svm_msg_q_t *event_queue;
 
+  u32 max_fifo_size;
   u8 high_watermark;
   u8 low_watermark;
 } segment_manager_t;
diff --git a/src/vnet/session/session.c b/src/vnet/session/session.c
index b006cfaf2bb..e9cda361f37 100644
--- a/src/vnet/session/session.c
+++ b/src/vnet/session/session.c
@@ -396,6 +396,24 @@ session_enqueue_chain_tail (session_t * s, vlib_buffer_t * b,
   return 0;
 }
 
+void
+session_fifo_tuning (session_t * s, svm_fifo_t * f,
+		     session_ft_action_t act, u32 len)
+{
+  if (s->flags & SESSION_F_CUSTOM_FIFO_TUNING)
+    {
+      app_worker_t *app_wrk = app_worker_get (s->app_wrk_index);
+      app_worker_session_fifo_tuning (app_wrk, s, f, act, len);
+      if (CLIB_ASSERT_ENABLE)
+	{
+	  segment_manager_t *sm;
+	  sm = segment_manager_get (f->segment_manager);
+	  ASSERT (f->size >= 4096);
+	  ASSERT (f->size <= sm->max_fifo_size);
+	}
+    }
+}
+
 /*
  * Enqueue data for delivery to session peer. Does not notify peer of enqueue
  * event but on request can queue notification events for later delivery by
@@ -458,6 +476,8 @@ session_enqueue_stream_connection (transport_connection_t * tc,
 	  s->flags |= SESSION_F_RX_EVT;
 	  vec_add1 (wrk->session_to_enqueue[tc->proto], s->session_index);
 	}
+
+      session_fifo_tuning (s, s->rx_fifo, SESSION_FT_ACTION_ENQUEUED, 0);
     }
 
   return enqueued;
@@ -495,6 +515,8 @@ session_enqueue_dgram_connection (session_t * s,
 	  s->flags |= SESSION_F_RX_EVT;
 	  vec_add1 (wrk->session_to_enqueue[proto], s->session_index);
 	}
+
+      session_fifo_tuning (s, s->rx_fifo, SESSION_FT_ACTION_ENQUEUED, 0);
     }
   return enqueued;
 }
@@ -514,6 +536,7 @@ session_tx_fifo_dequeue_drop (transport_connection_t * tc, u32 max_bytes)
   u32 rv;
 
   rv = svm_fifo_dequeue_drop (s->tx_fifo, max_bytes);
+  session_fifo_tuning (s, s->tx_fifo, SESSION_FT_ACTION_DEQUEUED, rv);
 
   if (svm_fifo_needs_deq_ntf (s->tx_fifo, max_bytes))
     session_dequeue_notify (s);
@@ -674,6 +697,9 @@ session_main_flush_enqueue_events (u8 transport_proto, u32 thread_index)
 	  continue;
 	}
 
+      session_fifo_tuning (s, s->rx_fifo, SESSION_FT_ACTION_ENQUEUED,
+			   0 /* TODO/not needed */ );
+
       if (PREDICT_FALSE (session_enqueue_notify_inline (s)))
 	errors++;
     }
diff --git a/src/vnet/session/session_types.h b/src/vnet/session/session_types.h
index be8ad9cdb83..aa0e8650747 100644
--- a/src/vnet/session/session_types.h
+++ b/src/vnet/session/session_types.h
@@ -123,6 +123,13 @@ typedef enum
   SESSION_CLEANUP_SESSION,
 } session_cleanup_ntf_t;
 
+typedef enum session_ft_action_
+{
+  SESSION_FT_ACTION_ENQUEUED,
+  SESSION_FT_ACTION_DEQUEUED,
+  SESSION_FT_ACTION_N_ACTIONS
+} session_ft_action_t;
+
 /*
  * Session states
  */
@@ -154,6 +161,7 @@ typedef enum
   _(CUSTOM_TX, "custom-tx")				\
   _(IS_MIGRATING, "migrating")				\
   _(UNIDIRECTIONAL, "unidirectional")			\
+  _(CUSTOM_FIFO_TUNING, "custom-fifo-tuning")		\
 
 typedef enum session_flags_bits_
 {