keepalive: add liveness callback

Adds and documents new callbacks that allow transitions to core
states other than dead to be reported to applications.

Signed-off-by: Remy Horton <remy.horton@intel.com>

doc/guides/rel_notes/release_16_07.rst

@@ -70,6 +70,12 @@ New Features
   * Enable RSS per network interface through the configuration file.
   * Streamline the CLI code.
 
+* **Added keepalive enhancements.**
+
+  Adds support for reporting of core states other than dead to
+  monitoring applications, enabling the support of broader liveness
+  reporting to external processes.
+
 
 Resolved Issues
 ---------------

examples/Makefile

@@ -1,6 +1,6 @@
 #   BSD LICENSE
 #
-#   Copyright(c) 2014 6WIND S.A.
+#   Copyright(c) 2016 6WIND S.A.
 #
 #   Redistribution and use in source and binary forms, with or without
 #   modification, are permitted provided that the following conditions

lib/librte_eal/bsdapp/eal/rte_eal_version.map

@@ -156,5 +156,6 @@ DPDK_16.07 {
 	global:
 
 	pci_get_sysfs_path;
+	rte_keepalive_register_alive_callback;
 
 } DPDK_16.04;

lib/librte_eal/common/include/rte_keepalive.h

@@ -63,11 +63,31 @@ enum rte_keepalive_state {
  *
  *  Receives a data pointer passed to rte_keepalive_create() and the id of the
  *  failed core.
+ *  @param data Data pointer passed to rte_keepalive_create()
+ *  @param id_core ID of the core that has failed
  */
 typedef void (*rte_keepalive_failure_callback_t)(
 	void *data,
 	const int id_core);
 
+/**
+ * Keepalive relay callback.
+ *
+ *  Receives a data pointer passed to rte_keepalive_register_relay_callback(),
+ *  the id of the core for which state is to be forwarded, and details of the
+ *  current core state.
+ *  @param data Data pointer passed to rte_keepalive_register_relay_callback()
+ *  @param id_core ID of the core for which state is being reported
+ *  @param core_state The current state of the core
+ *  @param Timestamp of when core was last seen alive
+ */
+typedef void (*rte_keepalive_relay_callback_t)(
+	void *data,
+	const int id_core,
+	enum rte_keepalive_state core_state,
+	uint64_t last_seen
+	);
+
 /**
  * Keepalive state structure.
  * @internal
@@ -115,4 +135,35 @@ void rte_keepalive_register_core(struct rte_keepalive *keepcfg,
 void
 rte_keepalive_mark_alive(struct rte_keepalive *keepcfg);
 
+/**
+ * Per-core sleep-time indication.
+ * @param *keepcfg
+ *   Keepalive structure pointer
+ *
+ * If CPU idling is enabled, this function needs to be called from within
+ * the main process loop of the LCore going to sleep, in order to avoid
+ * the LCore being mis-detected as dead.
+ */
+void
+rte_keepalive_mark_sleep(struct rte_keepalive *keepcfg);
+
+/**
+ * Registers a 'live core' callback.
+ *
+ * The complement of the 'dead core' callback. This is called when a
+ * core is known to be alive, and is intended for cases when an app
+ * needs to know 'liveness' beyond just knowing when a core has died.
+ *
+ * @param *keepcfg
+ *   Keepalive structure pointer
+ * @param callback
+ *   Function called upon detection of a dead core.
+ * @param data
+ *   Data pointer to be passed to function callback.
+ */
+void
+rte_keepalive_register_relay_callback(struct rte_keepalive *keepcfg,
+	rte_keepalive_relay_callback_t callback,
+	void *data);
+
 #endif /* _KEEPALIVE_H_ */

lib/librte_eal/common/rte_keepalive.c

@@ -64,6 +64,15 @@ struct rte_keepalive {
 	void *callback_data;
 	uint64_t tsc_initial;
 	uint64_t tsc_mhz;
+
+	/** Core state relay handler. */
+	rte_keepalive_relay_callback_t relay_callback;
+
+	/**
+	 * Core state relay handler app data.
+	 * Pointer is passed to live core handler.
+	 */
+	void *relay_callback_data;
 };
 
 static void
@@ -116,6 +125,13 @@ rte_keepalive_dispatch_pings(__rte_unused void *ptr_timer,
 		case RTE_KA_STATE_SLEEP: /* Idled core */
 			break;
 		}
+		if (keepcfg->relay_callback)
+			keepcfg->relay_callback(
+				keepcfg->relay_callback_data,
+				idx_core,
+				keepcfg->state_flags[idx_core],
+				keepcfg->last_alive[idx_core]
+				);
 	}
 }
 
@@ -137,6 +153,14 @@ rte_keepalive_create(rte_keepalive_failure_callback_t callback,
 	return keepcfg;
 }
 
+void rte_keepalive_register_relay_callback(struct rte_keepalive *keepcfg,
+	rte_keepalive_relay_callback_t callback,
+	void *data)
+{
+	keepcfg->relay_callback = callback;
+	keepcfg->relay_callback_data = data;
+}
+
 void
 rte_keepalive_register_core(struct rte_keepalive *keepcfg, const int id_core)
 {
@@ -151,3 +175,9 @@ rte_keepalive_mark_alive(struct rte_keepalive *keepcfg)
 {
 	keepcfg->state_flags[rte_lcore_id()] = RTE_KA_STATE_ALIVE;
 }
+
+void
+rte_keepalive_mark_sleep(struct rte_keepalive *keepcfg)
+{
+	keepcfg->state_flags[rte_lcore_id()] = RTE_KA_STATE_DOZING;
+}

lib/librte_eal/linuxapp/eal/rte_eal_version.map

@@ -159,5 +159,7 @@ DPDK_16.07 {
 	global:
 
 	pci_get_sysfs_path;
+	rte_keepalive_register_alive_callback;
+	rte_keepalive_register_relay_callback;
 
 } DPDK_16.04;