malloc: allow creating malloc heaps

Add API to allow creating new malloc heaps. They will be created
with socket ID's going above RTE_MAX_NUMA_NODES, to avoid clashing
with internal heaps.

This breaks the ABI, so document the change.

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

doc/guides/rel_notes/release_18_11.rst

@@ -180,6 +180,8 @@ ABI Changes
          - structure ``rte_mem_config`` has had its ``malloc_heaps`` array
            resized from ``RTE_MAX_NUMA_NODES`` to ``RTE_MAX_HEAPS`` value
          - structure ``rte_malloc_heap`` now has a ``heap_name`` member
+         - structure ``rte_eal_memconfig`` has been extended to contain next
+           socket ID for externally allocated segments
 
 
 Removed Items

lib/librte_eal/common/include/rte_eal_memconfig.h

@@ -75,6 +75,9 @@ struct rte_mem_config {
 	/* Heaps of Malloc */
 	struct malloc_heap malloc_heaps[RTE_MAX_HEAPS];
 
+	/* next socket ID for external malloc heap */
+	int next_socket_id;
+
 	/* address of mem_config in primary process. used to map shared config into
 	 * exact same address the primary process maps it.
 	 */

lib/librte_eal/common/include/rte_malloc.h

@@ -263,6 +263,25 @@ int
 rte_malloc_get_socket_stats(int socket,
 		struct rte_malloc_socket_stats *socket_stats);
 
+/**
+ * Creates a new empty malloc heap with a specified name.
+ *
+ * @note Heaps created via this call will automatically get assigned a unique
+ *   socket ID, which can be found using ``rte_malloc_heap_get_socket()``
+ *
+ * @param heap_name
+ *   Name of the heap to create.
+ *
+ * @return
+ *   - 0 on successful creation
+ *   - -1 in case of error, with rte_errno set to one of the following:
+ *     EINVAL - ``heap_name`` was NULL, empty or too long
+ *     EEXIST - heap by name of ``heap_name`` already exists
+ *     ENOSPC - no more space in internal config to store a new heap
+ */
+int __rte_experimental
+rte_malloc_heap_create(const char *heap_name);
+
 /**
  * Find socket ID corresponding to a named heap.
  *

lib/librte_eal/common/malloc_heap.c

@@ -29,6 +29,10 @@
 #include "malloc_heap.h"
 #include "malloc_mp.h"
 
+/* start external socket ID's at a very high number */
+#define CONST_MAX(a, b) (a > b ? a : b) /* RTE_MAX is not a constant */
+#define EXTERNAL_HEAP_MIN_SOCKET_ID (CONST_MAX((1 << 8), RTE_MAX_NUMA_NODES))
+
 static unsigned
 check_hugepage_sz(unsigned flags, uint64_t hugepage_sz)
 {
@@ -1019,6 +1023,36 @@ malloc_heap_dump(struct malloc_heap *heap, FILE *f)
 	rte_spinlock_unlock(&heap->lock);
 }
 
+int
+malloc_heap_create(struct malloc_heap *heap, const char *heap_name)
+{
+	struct rte_mem_config *mcfg = rte_eal_get_configuration()->mem_config;
+	uint32_t next_socket_id = mcfg->next_socket_id;
+
+	/* prevent overflow. did you really create 2 billion heaps??? */
+	if (next_socket_id > INT32_MAX) {
+		RTE_LOG(ERR, EAL, "Cannot assign new socket ID's\n");
+		rte_errno = ENOSPC;
+		return -1;
+	}
+
+	/* initialize empty heap */
+	heap->alloc_count = 0;
+	heap->first = NULL;
+	heap->last = NULL;
+	LIST_INIT(heap->free_head);
+	rte_spinlock_init(&heap->lock);
+	heap->total_size = 0;
+	heap->socket_id = next_socket_id;
+
+	/* we hold a global mem hotplug writelock, so it's safe to increment */
+	mcfg->next_socket_id++;
+
+	/* set up name */
+	strlcpy(heap->name, heap_name, RTE_HEAP_NAME_MAX_LEN);
+	return 0;
+}
+
 int
 rte_eal_malloc_heap_init(void)
 {
@@ -1026,6 +1060,9 @@ rte_eal_malloc_heap_init(void)
 	unsigned int i;
 
 	if (rte_eal_process_type() == RTE_PROC_PRIMARY) {
+		/* assign min socket ID to external heaps */
+		mcfg->next_socket_id = EXTERNAL_HEAP_MIN_SOCKET_ID;
+
 		/* assign names to default DPDK heaps */
 		for (i = 0; i < rte_socket_count(); i++) {
 			struct malloc_heap *heap = &mcfg->malloc_heaps[i];

lib/librte_eal/common/malloc_heap.h

@@ -33,6 +33,9 @@ void *
 malloc_heap_alloc_biggest(const char *type, int socket, unsigned int flags,
 		size_t align, bool contig);
 
+int
+malloc_heap_create(struct malloc_heap *heap, const char *heap_name);
+
 int
 malloc_heap_free(struct malloc_elem *elem);
 

lib/librte_eal/common/rte_malloc.c

@@ -311,3 +311,54 @@ rte_malloc_virt2iova(const void *addr)
 
 	return ms->iova + RTE_PTR_DIFF(addr, ms->addr);
 }
+
+int
+rte_malloc_heap_create(const char *heap_name)
+{
+	struct rte_mem_config *mcfg = rte_eal_get_configuration()->mem_config;
+	struct malloc_heap *heap = NULL;
+	int i, ret;
+
+	if (heap_name == NULL ||
+			strnlen(heap_name, RTE_HEAP_NAME_MAX_LEN) == 0 ||
+			strnlen(heap_name, RTE_HEAP_NAME_MAX_LEN) ==
+				RTE_HEAP_NAME_MAX_LEN) {
+		rte_errno = EINVAL;
+		return -1;
+	}
+	/* check if there is space in the heap list, or if heap with this name
+	 * already exists.
+	 */
+	rte_rwlock_write_lock(&mcfg->memory_hotplug_lock);
+
+	for (i = 0; i < RTE_MAX_HEAPS; i++) {
+		struct malloc_heap *tmp = &mcfg->malloc_heaps[i];
+		/* existing heap */
+		if (strncmp(heap_name, tmp->name,
+				RTE_HEAP_NAME_MAX_LEN) == 0) {
+			RTE_LOG(ERR, EAL, "Heap %s already exists\n",
+				heap_name);
+			rte_errno = EEXIST;
+			ret = -1;
+			goto unlock;
+		}
+		/* empty heap */
+		if (strnlen(tmp->name, RTE_HEAP_NAME_MAX_LEN) == 0) {
+			heap = tmp;
+			break;
+		}
+	}
+	if (heap == NULL) {
+		RTE_LOG(ERR, EAL, "Cannot create new heap: no space\n");
+		rte_errno = ENOSPC;
+		ret = -1;
+		goto unlock;
+	}
+
+	/* we're sure that we can create a new heap, so do it */
+	ret = malloc_heap_create(heap, heap_name);
+unlock:
+	rte_rwlock_write_unlock(&mcfg->memory_hotplug_lock);
+
+	return ret;
+}

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_create;
 	rte_malloc_heap_get_socket;
 	rte_malloc_heap_socket_is_external;
 	rte_mem_alloc_validator_register;