[dpdk-dev] [RFC 07/35] mempool: list objects when added in the mempool

[Olivier Matz]

Introduce a list entry in object header so they can be listed and
browsed. The objective is to introduce a more simple way to browse the
elements of a mempool.

The next commits will update rte_mempool_obj_iter() to use this list,
and remove the previous complex implementation.

Signed-off-by: Olivier Matz <olivier.matz at 6wind.com>
---
 lib/librte_mempool/rte_mempool.c |  2 ++
 lib/librte_mempool/rte_mempool.h | 15 ++++++++++++---
 2 files changed, 14 insertions(+), 3 deletions(-)

diff --git a/lib/librte_mempool/rte_mempool.c b/lib/librte_mempool/rte_mempool.c
index 83e7ed6..1fe102f 100644
--- a/lib/librte_mempool/rte_mempool.c
+++ b/lib/librte_mempool/rte_mempool.c
@@ -138,6 +138,7 @@ mempool_add_elem(struct rte_mempool *mp, void *obj, uint32_t obj_idx,
 	/* set mempool ptr in header */
 	hdr = RTE_PTR_SUB(obj, sizeof(*hdr));
 	hdr->mp = mp;
+	STAILQ_INSERT_TAIL(&mp->elt_list, hdr, next);
 
 #ifdef RTE_LIBRTE_MEMPOOL_DEBUG
 	hdr->cookie = RTE_MEMPOOL_HEADER_COOKIE2;
@@ -585,6 +586,7 @@ rte_mempool_xmem_create(const char *name, unsigned n, unsigned elt_size,
 	mp->cache_size = cache_size;
 	mp->cache_flushthresh = CALC_CACHE_FLUSHTHRESH(cache_size);
 	mp->private_data_size = private_data_size;
+	STAILQ_INIT(&mp->elt_list);
 
 	/*
 	 * local_cache pointer is set even if cache_size is zero.
diff --git a/lib/librte_mempool/rte_mempool.h b/lib/librte_mempool/rte_mempool.h
index da04021..469bcbc 100644
--- a/lib/librte_mempool/rte_mempool.h
+++ b/lib/librte_mempool/rte_mempool.h
@@ -150,11 +150,13 @@ struct rte_mempool_objsz {
  * Mempool object header structure
  *
  * Each object stored in mempools are prefixed by this header structure,
- * it allows to retrieve the mempool pointer from the object. When debug
- * is enabled, a cookie is also added in this structure preventing
- * corruptions and double-frees.
+ * it allows to retrieve the mempool pointer from the object and to
+ * iterate on all objects attached to a mempool. When debug is enabled,
+ * a cookie is also added in this structure preventing corruptions and
+ * double-frees.
  */
 struct rte_mempool_objhdr {
+	STAILQ_ENTRY(rte_mempool_objhdr) next; /**< Next in list. */
 	struct rte_mempool *mp;          /**< The mempool owning the object. */
 #ifdef RTE_LIBRTE_MEMPOOL_DEBUG
 	uint64_t cookie;                 /**< Debug cookie. */
@@ -162,6 +164,11 @@ struct rte_mempool_objhdr {
 };
 
 /**
+ * A list of object headers type
+ */
+STAILQ_HEAD(rte_mempool_objhdr_list, rte_mempool_objhdr);
+
+/**
  * Mempool object trailer structure
  *
  * In debug mode, each object stored in mempools are suffixed by this
@@ -194,6 +201,8 @@ struct rte_mempool {
 
 	struct rte_mempool_cache *local_cache; /**< Per-lcore local cache */
 
+	struct rte_mempool_objhdr_list elt_list; /**< List of objects in pool */
+
 #ifdef RTE_LIBRTE_MEMPOOL_DEBUG
 	/** Per-lcore statistics. */
 	struct rte_mempool_debug_stats stats[RTE_MAX_LCORE];
-- 
2.1.4