[dpdk-dev] [PATCH 3/3] lib/hash: adjust tbl_chng_cnt position

[Honnappa Nagarahalli <honnappa.nagarahalli@arm.com>]

tbl_chng_cnt is one of the first elements of the structure used in
the lookup. Move it to the beginning of the cache line to gain
performance.

Fixes: e605a1d36 ("hash: add lock-free r/w concurrency")
Cc: stable@dpdk.org

Signed-off-by: Honnappa Nagarahalli <honnappa.nagarahalli@arm.com>
Reviewed-by: Gavin Hu <gavin.hu@arm.com>
Tested-by: Ruifeng Wang <ruifeng.wang@arm.com>
---
 lib/librte_hash/rte_cuckoo_hash.h | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/lib/librte_hash/rte_cuckoo_hash.h b/lib/librte_hash/rte_cuckoo_hash.h
index fb19bb27d..af6451b5c 100644
--- a/lib/librte_hash/rte_cuckoo_hash.h
+++ b/lib/librte_hash/rte_cuckoo_hash.h
@@ -170,7 +170,9 @@ struct rte_hash {
 
 	/* Fields used in lookup */
 
-	uint32_t key_len __rte_cache_aligned;
+	uint32_t *tbl_chng_cnt __rte_cache_aligned;
+	/**< Indicates if the hash table changed from last read. */
+	uint32_t key_len;
 	/**< Length of hash key. */
 	uint8_t hw_trans_mem_support;
 	/**< If hardware transactional memory is used. */
@@ -218,8 +220,6 @@ struct rte_hash {
 	 * is piggy-backed to freeing of the key index.
 	 */
 	uint32_t *ext_bkt_to_free;
-	uint32_t *tbl_chng_cnt;
-	/**< Indicates if the hash table changed from last read. */
 } __rte_cache_aligned;
 
 struct queue_node {
-- 
2.17.1