[dpdk-dev] [PATCH] Add rte_mempool_free

[Ben Walker]

There is no inverse of rte_mempool_create, so this patch adds one.
The typical usage of rte_mempool_create is to create a pool at
initialization time and only to free it upon program exit, so an
rte_mempool_free function at first seems to be of little value.
However, it is very useful as a sanity check for a clean shutdown
when used in conjunction with tools like AddressSanitizer. Further,
the call itself verifies that all elements have been returned to
the pool or it fails.

Signed-off-by: Ben Walker <benjamin.walker at intel.com>
---
 lib/librte_mempool/rte_dom0_mempool.c | 22 +++++++++++
 lib/librte_mempool/rte_mempool.c      | 70 +++++++++++++++++++++++++++++++++++
 lib/librte_mempool/rte_mempool.h      | 41 ++++++++++++++++++++
 3 files changed, 133 insertions(+)

diff --git a/lib/librte_mempool/rte_dom0_mempool.c b/lib/librte_mempool/rte_dom0_mempool.c
index 0d6d750..edf2d58 100644
--- a/lib/librte_mempool/rte_dom0_mempool.c
+++ b/lib/librte_mempool/rte_dom0_mempool.c
@@ -131,3 +131,25 @@ rte_dom0_mempool_create(const char *name, unsigned elt_num, unsigned elt_size,
 
 	return mp;
 }
+
+/* free the mempool supporting Dom0 */
+int
+rte_dom0_mempool_free(struct rte_mempool *mp)
+{
+	const struct rte_memzone *mz;
+	char mz_name[RTE_MEMZONE_NAMESIZE];
+	int rc;
+
+	rc = rte_mempool_xmem_free(mp);
+	if (rc) {
+		return rc;
+	}
+
+	snprintf(mz_name, sizeof(mz_name), RTE_MEMPOOL_OBJ_NAME, mp->name);
+	mz = rte_memzone_lookup(mz_name);
+	if (mz) {
+		rte_memzone_free(mz);
+	}
+
+	return 0;
+}
diff --git a/lib/librte_mempool/rte_mempool.c b/lib/librte_mempool/rte_mempool.c
index 70812d9..82f645e 100644
--- a/lib/librte_mempool/rte_mempool.c
+++ b/lib/librte_mempool/rte_mempool.c
@@ -638,6 +638,76 @@ exit_unlock:
 	return NULL;
 }
 
+#ifndef RTE_LIBRTE_XEN_DOM0
+/* stub if DOM0 support not configured */
+int
+rte_dom0_mempool_free(struct rte_mempool *mp __rte_unused)
+{
+	rte_errno = EINVAL;
+	return -1;
+}
+#endif
+
+int
+rte_mempool_free(struct rte_mempool *mp)
+{
+	if (rte_xen_dom0_supported())
+		return rte_dom0_mempool_free(mp);
+	else
+		return rte_mempool_xmem_free(mp);
+}
+
+
+/* Free the memory pool */
+int
+rte_mempool_xmem_free(struct rte_mempool *mp)
+{
+	char mz_name[RTE_MEMZONE_NAMESIZE];
+	struct rte_mempool_list *mempool_list;
+	struct rte_tailq_entry *te = NULL;
+	const struct rte_memzone *mz;
+	unsigned count;
+
+	if (!mp) {
+		return 0;
+	}
+
+	count = rte_mempool_free_count(mp);
+	if (count != 0) {
+		/* All elements must be returned to the pool before free */
+		return count;
+	}
+
+	rte_rwlock_write_lock(RTE_EAL_MEMPOOL_RWLOCK);
+
+	/* Free the ring associated with this mempool */
+	if (mp->ring) {
+		rte_ring_free(mp->ring);
+	}
+
+	/* Remove the entry from the mempool list and free it. */
+	rte_rwlock_write_lock(RTE_EAL_TAILQ_RWLOCK);
+	mempool_list = RTE_TAILQ_CAST(rte_mempool_tailq.head, rte_mempool_list);
+	TAILQ_FOREACH(te, mempool_list, next) {
+		if ((struct rte_mempool *)te->data == mp) {
+			TAILQ_REMOVE(mempool_list, te, next);
+			rte_free(te);
+			break;
+		}
+	}
+	rte_rwlock_write_unlock(RTE_EAL_TAILQ_RWLOCK);
+
+	snprintf(mz_name, sizeof(mz_name), RTE_MEMPOOL_MZ_FORMAT, mp->name);
+	mz = rte_memzone_lookup(mz_name);
+	if (mz) {
+		rte_memzone_free(mz);
+	}
+
+	rte_rwlock_write_unlock(RTE_EAL_MEMPOOL_RWLOCK);
+
+	return 0;
+}
+
 /* Return the number of entries in the mempool */
 unsigned
 rte_mempool_count(const struct rte_mempool *mp)
diff --git a/lib/librte_mempool/rte_mempool.h b/lib/librte_mempool/rte_mempool.h
index 9745bf0..26949c7 100644
--- a/lib/librte_mempool/rte_mempool.h
+++ b/lib/librte_mempool/rte_mempool.h
@@ -728,6 +728,47 @@ rte_dom0_mempool_create(const char *name, unsigned n, unsigned elt_size,
 		rte_mempool_obj_ctor_t *obj_init, void *obj_init_arg,
 		int socket_id, unsigned flags);
 
+/**
+ * Free the memory pool created by rte_mempool_create
+ *
+ * All elements must be placed back in the pool prior to calling this function.
+ *
+ * @param mp
+ *   A pointer to the mempool structure.
+ * @return
+ *   0 on success. -1 on error  with rte_errno set appropriately.
+ *     Possible rte_errno values include:
+ *    - EINVAL - Invalid input value.
+ */
+int rte_mempool_free(struct rte_mempool *mp);
+
+/**
+ * Free the memory pool created by rte_mempool_xmem_create.
+ *
+ * All elements must be placed back in the pool prior to calling this function.
+ *
+ * @param mp
+ *   A pointer to the mempool structure.
+ * @return
+ *   0 on success. -1 on error  with rte_errno set appropriately.
+ *     Possible rte_errno values include:
+ *    - EINVAL - Invalid input value.
+ */
+int rte_mempool_xmem_free(struct rte_mempool *mp);
+
+/**
+ * Free the memory pool created by rte_dom0_mempool_create.
+ *
+ * All elements must be placed back in the pool prior to calling this function.
+ *
+ * @param mp
+ *   A pointer to the mempool structure.
+ * @return
+ *   0 on success. -1 on error  with rte_errno set appropriately.
+ *     Possible rte_errno values include:
+ *    - EINVAL - Invalid input value.
+ */
+int rte_dom0_mempool_free(struct rte_mempool *mp);
 
 /**
  * Dump the status of the mempool to the console.
-- 
2.5.5