eal: set name when creating a control thread

To avoid code duplication, add a parameter to rte_ctrl_thread_create()
to specify the name of the thread.

This requires to add a wrapper for the thread start routine in
rte_thread_init(), which will first wait that the thread is configured.

Signed-off-by: Olivier Matz <olivier.matz@6wind.com>
Reviewed-by: Anatoly Burakov <anatoly.burakov@intel.com>

drivers/net/kni/rte_eth_kni.c

@@ -149,7 +149,8 @@ eth_kni_dev_start(struct rte_eth_dev *dev)
 	}
 
 	if (internals->no_request_thread == 0) {
-		ret = rte_ctrl_thread_create(&internals->thread, NULL,
+		ret = rte_ctrl_thread_create(&internals->thread,
+			"kni_handle_req", NULL,
 			kni_handle_request, internals);
 		if (ret) {
 			RTE_LOG(ERR, PMD,

lib/librte_eal/common/eal_common_proc.c

@@ -622,7 +622,6 @@ unlink_sockets(const char *filter)
 int
 rte_mp_channel_init(void)
 {
-	char thread_name[RTE_MAX_THREAD_NAME_LEN];
 	char path[PATH_MAX];
 	int dir_fd;
 	pthread_t mp_handle_tid, async_reply_handle_tid;
@@ -662,7 +661,8 @@ rte_mp_channel_init(void)
 		return -1;
 	}
 
-	if (rte_ctrl_thread_create(&mp_handle_tid, NULL, mp_handle, NULL) < 0) {
+	if (rte_ctrl_thread_create(&mp_handle_tid, "rte_mp_handle",
+			NULL, mp_handle, NULL) < 0) {
 		RTE_LOG(ERR, EAL, "failed to create mp thead: %s\n",
 			strerror(errno));
 		close(mp_fd);
@@ -671,7 +671,8 @@ rte_mp_channel_init(void)
 		return -1;
 	}
 
-	if (rte_ctrl_thread_create(&async_reply_handle_tid, NULL,
+	if (rte_ctrl_thread_create(&async_reply_handle_tid,
+			"rte_mp_async", NULL,
 			async_reply_handle, NULL) < 0) {
 		RTE_LOG(ERR, EAL, "failed to create mp thead: %s\n",
 			strerror(errno));
@@ -681,14 +682,6 @@ rte_mp_channel_init(void)
 		return -1;
 	}
 
-	/* try best to set thread name */
-	strlcpy(thread_name, "rte_mp_handle", sizeof(thread_name));
-	rte_thread_setname(mp_handle_tid, thread_name);
-
-	/* try best to set thread name */
-	strlcpy(thread_name, "rte_mp_async_handle", sizeof(thread_name));
-	rte_thread_setname(async_reply_handle_tid, thread_name);
-
 	/* unlock the directory */
 	flock(dir_fd, LOCK_UN);
 	close(dir_fd);

lib/librte_eal/common/eal_common_thread.c

@@ -7,6 +7,7 @@
 #include <stdint.h>
 #include <unistd.h>
 #include <pthread.h>
+#include <signal.h>
 #include <sched.h>
 #include <assert.h>
 #include <string.h>
@@ -141,10 +142,53 @@ eal_thread_dump_affinity(char *str, unsigned size)
 	return ret;
 }
 
-__rte_experimental int
-rte_ctrl_thread_create(pthread_t *thread,
-			const pthread_attr_t *attr,
-			void *(*start_routine)(void *), void *arg)
+
+struct rte_thread_ctrl_params {
+	void *(*start_routine)(void *);
+	void *arg;
+	pthread_barrier_t configured;
+};
+
+static void *rte_thread_init(void *arg)
 {
-	return pthread_create(thread, attr, start_routine, arg);
+	struct rte_thread_ctrl_params *params = arg;
+	void *(*start_routine)(void *) = params->start_routine;
+	void *routine_arg = params->arg;
+
+	pthread_barrier_wait(&params->configured);
+
+	return start_routine(routine_arg);
+}
+
+__rte_experimental int
+rte_ctrl_thread_create(pthread_t *thread, const char *name,
+		const pthread_attr_t *attr,
+		void *(*start_routine)(void *), void *arg)
+{
+	struct rte_thread_ctrl_params params = {
+		.start_routine = start_routine,
+		.arg = arg,
+	};
+	int ret;
+
+	pthread_barrier_init(&params.configured, NULL, 2);
+
+	ret = pthread_create(thread, attr, rte_thread_init, (void *)&params);
+	if (ret != 0)
+		return ret;
+
+	if (name != NULL) {
+		ret = rte_thread_setname(*thread, name);
+		if (ret < 0)
+			goto fail;
+	}
+
+	pthread_barrier_wait(&params.configured);
+
+	return 0;
+
+fail:
+	pthread_cancel(*thread);
+	pthread_join(*thread, NULL);
+	return ret;
 }

lib/librte_eal/common/include/rte_lcore.h

@@ -279,10 +279,12 @@ int rte_thread_setname(pthread_t id, const char *name);
 /**
  * Create a control thread.
  *
- * Wrapper to pthread_create().
+ * Wrapper to pthread_create() and pthread_setname_np().
  *
  * @param thread
  *   Filled with the thread id of the new created thread.
+ * @param name
+ *   The name of the control thread (max 16 characters including '\0').
  * @param attr
  *   Attributes for the new thread.
  * @param start_routine
@@ -294,7 +296,8 @@ int rte_thread_setname(pthread_t id, const char *name);
  *   corresponding to the error number.
  */
 __rte_experimental int
-rte_ctrl_thread_create(pthread_t *thread, const pthread_attr_t *attr,
+rte_ctrl_thread_create(pthread_t *thread, const char *name,
+		const pthread_attr_t *attr,
 		void *(*start_routine)(void *), void *arg);
 
 /**

lib/librte_eal/linuxapp/eal/eal_interrupts.c

@@ -853,8 +853,7 @@ eal_intr_thread_main(__rte_unused void *arg)
 int
 rte_eal_intr_init(void)
 {
-	int ret = 0, ret_1 = 0;
-	char thread_name[RTE_MAX_THREAD_NAME_LEN];
+	int ret = 0;
 
 	/* init the global interrupt source head */
 	TAILQ_INIT(&intr_sources);
@@ -869,20 +868,12 @@ rte_eal_intr_init(void)
 	}
 
 	/* create the host thread to wait/handle the interrupt */
-	ret = rte_ctrl_thread_create(&intr_thread, NULL,
+	ret = rte_ctrl_thread_create(&intr_thread, "eal-intr-thread", NULL,
 			eal_intr_thread_main, NULL);
 	if (ret != 0) {
 		rte_errno = -ret;
 		RTE_LOG(ERR, EAL,
 			"Failed to create thread for interrupt handling\n");
-	} else {
-		/* Set thread_name for aid in debugging. */
-		snprintf(thread_name, sizeof(thread_name),
-			"eal-intr-thread");
-		ret_1 = rte_thread_setname(intr_thread, thread_name);
-		if (ret_1 != 0)
-			RTE_LOG(DEBUG, EAL,
-			"Failed to set thread name for interrupt handling\n");
 	}
 
 	return ret;

lib/librte_eal/linuxapp/eal/eal_timer.c

@@ -137,7 +137,6 @@ int
 rte_eal_hpet_init(int make_default)
 {
 	int fd, ret;
-	char thread_name[RTE_MAX_THREAD_NAME_LEN];
 
 	if (internal_config.no_hpet) {
 		RTE_LOG(NOTICE, EAL, "HPET is disabled\n");
@@ -178,7 +177,7 @@ rte_eal_hpet_init(int make_default)
 
 	/* create a thread that will increment a global variable for
 	 * msb (hpet is 32 bits by default under linux) */
-	ret = rte_ctrl_thread_create(&msb_inc_thread_id, NULL,
+	ret = rte_ctrl_thread_create(&msb_inc_thread_id, "hpet-msb-inc", NULL,
 			(void *(*)(void *))hpet_msb_inc, NULL);
 	if (ret != 0) {
 		RTE_LOG(ERR, EAL, "ERROR: Cannot create HPET timer thread!\n");
@@ -186,15 +185,6 @@ rte_eal_hpet_init(int make_default)
 		return -1;
 	}
 
-	/*
-	 * Set thread_name for aid in debugging.
-	 */
-	snprintf(thread_name, sizeof(thread_name), "hpet-msb-inc");
-	ret = rte_thread_setname(msb_inc_thread_id, thread_name);
-	if (ret != 0)
-		RTE_LOG(DEBUG, EAL,
-			"Cannot set HPET timer thread name!\n");
-
 	if (make_default)
 		eal_timer_source = EAL_TIMER_HPET;
 	return 0;

lib/librte_vhost/socket.c

@@ -467,7 +467,6 @@ static int
 vhost_user_reconnect_init(void)
 {
 	int ret;
-	char thread_name[RTE_MAX_THREAD_NAME_LEN];
 
 	ret = pthread_mutex_init(&reconn_list.mutex, NULL);
 	if (ret < 0) {
@@ -476,7 +475,7 @@ vhost_user_reconnect_init(void)
 	}
 	TAILQ_INIT(&reconn_list.head);
 
-	ret = rte_ctrl_thread_create(&reconn_tid, NULL,
+	ret = rte_ctrl_thread_create(&reconn_tid, "vhost_reconn", NULL,
 			     vhost_user_client_reconnect, NULL);
 	if (ret != 0) {
 		RTE_LOG(ERR, VHOST_CONFIG, "failed to create reconnect thread");
@@ -484,14 +483,6 @@ vhost_user_reconnect_init(void)
 			RTE_LOG(ERR, VHOST_CONFIG,
 				"failed to destroy reconnect mutex");
 		}
-	} else {
-		snprintf(thread_name, sizeof(thread_name),
-			 "vhost-reconn");
-
-		if (rte_thread_setname(reconn_tid, thread_name)) {
-			RTE_LOG(DEBUG, VHOST_CONFIG,
-				"failed to set reconnect thread name");
-		}
 	}
 
 	return ret;
@@ -1000,7 +991,6 @@ rte_vhost_driver_start(const char *path)
 {
 	struct vhost_user_socket *vsocket;
 	static pthread_t fdset_tid;
-	char thread_name[RTE_MAX_THREAD_NAME_LEN];
 
 	pthread_mutex_lock(&vhost_user.mutex);
 	vsocket = find_vhost_user_socket(path);
@@ -1020,22 +1010,15 @@ rte_vhost_driver_start(const char *path)
 			return -1;
 		}
 
-		int ret = rte_ctrl_thread_create(&fdset_tid, NULL,
-			fdset_event_dispatch, &vhost_user.fdset);
+		int ret = rte_ctrl_thread_create(&fdset_tid,
+			"vhost-events", NULL, fdset_event_dispatch,
+			&vhost_user.fdset);
 		if (ret != 0) {
 			RTE_LOG(ERR, VHOST_CONFIG,
 				"failed to create fdset handling thread");
 
 			fdset_pipe_uninit(&vhost_user.fdset);
 			return -1;
-		} else {
-			snprintf(thread_name, sizeof(thread_name),
-				 "vhost-events");
-
-			if (rte_thread_setname(fdset_tid, thread_name)) {
-				RTE_LOG(DEBUG, VHOST_CONFIG,
-					"failed to set vhost-event thread name");
-			}
 		}
 	}