malloc: add function to query socket ID of named heap

When we will be creating external heaps, they will have their own
"fake" socket ID, so add a function that will map the heap name
to its socket ID.

Signed-off-by: Anatoly Burakov <anatoly.burakov@intel.com>

lib/librte_eal/common/include/rte_malloc.h

@@ -263,6 +263,20 @@ int
 rte_malloc_get_socket_stats(int socket,
 		struct rte_malloc_socket_stats *socket_stats);
 
+/**
+ * Find socket ID corresponding to a named heap.
+ *
+ * @param name
+ *   Heap name to find socket ID for
+ * @return
+ *   Socket ID in case of success (a non-negative number)
+ *   -1 in case of error, with rte_errno set to one of the following:
+ *     EINVAL - ``name`` was NULL
+ *     ENOENT - heap identified by the name ``name`` was not found
+ */
+int __rte_experimental
+rte_malloc_heap_get_socket(const char *name);
+
 /**
  * Dump statistics.
  *

lib/librte_eal/common/rte_malloc.c

@@ -8,6 +8,7 @@
 #include <string.h>
 #include <sys/queue.h>
 
+#include <rte_errno.h>
 #include <rte_memcpy.h>
 #include <rte_memory.h>
 #include <rte_eal.h>
@@ -183,6 +184,42 @@ rte_malloc_dump_heaps(FILE *f)
 	rte_rwlock_read_unlock(&mcfg->memory_hotplug_lock);
 }
 
+int
+rte_malloc_heap_get_socket(const char *name)
+{
+	struct rte_mem_config *mcfg = rte_eal_get_configuration()->mem_config;
+	struct malloc_heap *heap = NULL;
+	unsigned int idx;
+	int ret;
+
+	if (name == NULL ||
+			strnlen(name, RTE_HEAP_NAME_MAX_LEN) == 0 ||
+			strnlen(name, RTE_HEAP_NAME_MAX_LEN) ==
+				RTE_HEAP_NAME_MAX_LEN) {
+		rte_errno = EINVAL;
+		return -1;
+	}
+	rte_rwlock_read_lock(&mcfg->memory_hotplug_lock);
+	for (idx = 0; idx < RTE_MAX_HEAPS; idx++) {
+		struct malloc_heap *tmp = &mcfg->malloc_heaps[idx];
+
+		if (!strncmp(name, tmp->name, RTE_HEAP_NAME_MAX_LEN)) {
+			heap = tmp;
+			break;
+		}
+	}
+
+	if (heap != NULL) {
+		ret = heap->socket_id;
+	} else {
+		rte_errno = ENOENT;
+		ret = -1;
+	}
+	rte_rwlock_read_unlock(&mcfg->memory_hotplug_lock);
+
+	return ret;
+}
+
 /*
  * Print stats on memory type. If type is NULL, info on all types is printed
  */

lib/librte_eal/rte_eal_version.map

@@ -318,6 +318,7 @@ EXPERIMENTAL {
 	rte_fbarray_set_used;
 	rte_log_register_type_and_pick_level;
 	rte_malloc_dump_heaps;
+	rte_malloc_heap_get_socket;
 	rte_mem_alloc_validator_register;
 	rte_mem_alloc_validator_unregister;
 	rte_mem_event_callback_register;