[PATCH] eal: increase memzone name size to 64

[Stephen Hemminger <stephen@networkplumber.org>]

Memzone names are limited to 31 characters, and ring, mempool and
stack names lose the length of their prefixes on top of that.
A mempool name is limited to 25 characters, which leaves little room
for libraries such as rib and fib that derive names from the name
given by the application.

Increase RTE_MEMZONE_NAMESIZE to 64. The derived ring, mempool,
stack and RCU defer queue sizes follow.

Move name out of the first cache line of struct rte_ring and
struct rte_mempool so the larger name does not push datapath
fields into another cache line. For mempool this also brings
local_cache, cache_size and ops_index into the first cache line,
where previously they were in the second. struct rte_mempool
stays 192 bytes; struct rte_ring grows by one cache line.

Signed-off-by: Stephen Hemminger <stephen@networkplumber.org>
---
 doc/guides/rel_notes/release_26_11.rst | 19 +++++++++++++++++++
 lib/eal/include/rte_memzone.h          |  2 +-
 lib/mempool/rte_mempool.h              |  8 ++++----
 lib/ring/rte_ring_core.h               |  5 ++---
 4 files changed, 26 insertions(+), 8 deletions(-)

diff --git a/doc/guides/rel_notes/release_26_11.rst b/doc/guides/rel_notes/release_26_11.rst
index 4b3e5d995c..380aecb5a7 100644
--- a/doc/guides/rel_notes/release_26_11.rst
+++ b/doc/guides/rel_notes/release_26_11.rst
@@ -139,6 +139,25 @@ ABI Changes
    Also, make sure to start the actual text at the margin.
    =======================================================
 
+* **Increased memzone maximum name size.**
+
+  ``RTE_MEMZONE_NAMESIZE`` was increased from 32 to 64,
+  and the derived ``RTE_RING_NAMESIZE``, ``RTE_MEMPOOL_NAMESIZE``,
+  ``RTE_STACK_NAMESIZE`` and ``RTE_RCU_QSBR_DQ_NAMESIZE`` grew accordingly.
+  This impacts the following structures:
+
+  * ``struct rte_memzone`` grew by 32 bytes.
+
+  * ``struct rte_ring`` grew by one cache line,
+    and ``name`` was moved after the size fields
+    to keep the datapath fields in the first cache line.
+
+  * ``struct rte_mempool`` is unchanged in size,
+    but ``name``, ``pool_config`` and ``mz`` were moved
+    after the fields used in the datapath.
+
+  * ``struct rte_stack`` grew by one cache line.
+
 
 Known Issues
 ------------
diff --git a/lib/eal/include/rte_memzone.h b/lib/eal/include/rte_memzone.h
index 5a0e1b8a15..d5c92fe0ec 100644
--- a/lib/eal/include/rte_memzone.h
+++ b/lib/eal/include/rte_memzone.h
@@ -47,7 +47,7 @@ extern "C" {
  */
 struct __rte_packed_begin rte_memzone {
 
-#define RTE_MEMZONE_NAMESIZE 32       /**< Maximum length of memory zone name.*/
+#define RTE_MEMZONE_NAMESIZE 64       /**< Maximum length of memory zone name.*/
 	char name[RTE_MEMZONE_NAMESIZE];  /**< Name of the memory zone. */
 
 	rte_iova_t iova;                  /**< Start IO address. */
diff --git a/lib/mempool/rte_mempool.h b/lib/mempool/rte_mempool.h
index 50d958c7c6..d2ae56e49f 100644
--- a/lib/mempool/rte_mempool.h
+++ b/lib/mempool/rte_mempool.h
@@ -230,13 +230,11 @@ struct __rte_cache_aligned rte_mempool_info {
  * The RTE mempool structure.
  */
 struct __rte_cache_aligned rte_mempool {
-	char name[RTE_MEMPOOL_NAMESIZE]; /**< Name of mempool. */
 	union {
 		void *pool_data;         /**< Ring or pool to store objects. */
 		uint64_t pool_id;        /**< External mempool identifier. */
 	};
-	void *pool_config;               /**< optional args for ops alloc. */
-	const struct rte_memzone *mz;    /**< Memzone where pool is alloc'd. */
+	struct rte_mempool_cache *local_cache; /**< Per-lcore local cache */
 	unsigned int flags;              /**< Flags of the mempool. */
 	int socket_id;                   /**< Socket id passed at create. */
 	uint32_t size;                   /**< Max size of the mempool. */
@@ -257,7 +255,9 @@ struct __rte_cache_aligned rte_mempool {
 	 */
 	int32_t ops_index;
 
-	struct rte_mempool_cache *local_cache; /**< Per-lcore local cache */
+	void *pool_config;               /**< optional args for ops alloc. */
+	const struct rte_memzone *mz;    /**< Memzone where pool is alloc'd. */
+	char name[RTE_MEMPOOL_NAMESIZE]; /**< Name of mempool. */
 
 	uint32_t populated_size;         /**< Number of populated objects. */
 	struct rte_mempool_objhdr_list elt_list; /**< List of objects in pool */
diff --git a/lib/ring/rte_ring_core.h b/lib/ring/rte_ring_core.h
index 6cd6ce9884..4359ca8006 100644
--- a/lib/ring/rte_ring_core.h
+++ b/lib/ring/rte_ring_core.h
@@ -114,14 +114,13 @@ struct rte_ring_hts_headtail {
  * a problem.
  */
 struct rte_ring {
-	alignas(RTE_CACHE_LINE_SIZE) char name[RTE_RING_NAMESIZE];
-	/**< Name of the ring. */
-	int flags;               /**< Flags supplied at creation. */
+	alignas(RTE_CACHE_LINE_SIZE) int flags; /**< Flags supplied at creation. */
 	const struct rte_memzone *memzone;
 			/**< Memzone, if any, containing the rte_ring */
 	uint32_t size;           /**< Size of ring. */
 	uint32_t mask;           /**< Mask (size-1) of ring. */
 	uint32_t capacity;       /**< Usable size of ring */
+	char name[RTE_RING_NAMESIZE]; /**< Name of the ring. */
 
 	RTE_CACHE_GUARD;
 
-- 
2.53.0