hash: fix scaling by reducing contention

If using multiple cores on a system with hardware transactional
memory support, thread scaling does not work, as there was a single
point in the hash library which is a bottleneck for all threads,
which is the "free_slots" ring, which stores all the indices of
the free slots in the table.

This patch fixes the problem, by creating a local cache per logical core,
which stores locally indices of free slots,
so most times, writer threads will not interfere each other.

Fixes: 48a399119619 ("hash: replace with cuckoo hash implementation")

Signed-off-by: Pablo de Lara <pablo.de.lara.guarch@intel.com>
Acked-by: Bruce Richardson <bruce.richardson@intel.com>

1 files changed, 1 insertions, 0 deletions

diff --git a/app/test/test_hash_scaling.c b/app/test/test_hash_scaling.c
index 39602cb..744e5e3 100644
--- a/app/test/test_hash_scaling.c
+++ b/app/test/test_hash_scaling.c
@@ -133,6 +133,7 @@ test_hash_scaling(int locking_mode)
 		.hash_func = rte_hash_crc,
 		.hash_func_init_val = 0,
 		.socket_id = rte_socket_id(),
+		.extra_flag = RTE_HASH_EXTRA_FLAGS_TRANS_MEM_SUPPORT
 	};
 	struct rte_hash *handle;
 	char name[RTE_HASH_NAMESIZE];