diff mbox series

[v2,5/6] hash: fix to have more accurate key slot size

Message ID 1530275097-123488-6-git-send-email-yipeng1.wang@intel.com (mailing list archive)
State Superseded, archived
Delegated to: Thomas Monjalon
Headers show
Series Add read-write concurrency to rte_hash library | expand

Checks

Context Check Description
ci/checkpatch success coding style OK
ci/Intel-compilation success Compilation OK

Commit Message

Wang, Yipeng1 June 29, 2018, 12:24 p.m. UTC
This commit calculates the needed key slot size more
accurately. The previous local cache fix requires
the free slot ring to be larger than actually needed.
The calculation of the value is inaccurate.

Fixes: 5915699153d7 ("hash: fix scaling by reducing contention")

Signed-off-by: Yipeng Wang <yipeng1.wang@intel.com>
---
 lib/librte_hash/rte_cuckoo_hash.c | 16 +++++++++++-----
 1 file changed, 11 insertions(+), 5 deletions(-)

Comments

Pablo de Lara July 6, 2018, 5:32 p.m. UTC | #1
> -----Original Message-----
> From: Wang, Yipeng1
> Sent: Friday, June 29, 2018 1:25 PM
> To: De Lara Guarch, Pablo <pablo.de.lara.guarch@intel.com>
> Cc: dev@dpdk.org; Wang, Yipeng1 <yipeng1.wang@intel.com>; Richardson,
> Bruce <bruce.richardson@intel.com>; honnappa.nagarahalli@arm.com;
> vguvva@caviumnetworks.com; brijesh.s.singh@gmail.com
> Subject: [PATCH v2 5/6] hash: fix to have more accurate key slot size
> 
> This commit calculates the needed key slot size more accurately. The previous
> local cache fix requires the free slot ring to be larger than actually needed.
> The calculation of the value is inaccurate.
> 
> Fixes: 5915699153d7 ("hash: fix scaling by reducing contention")

Missing "Cc: stable@dpdk.org).

Also, could you add this as the first patch of the set.
That way, it would be easier to backport (the patch will need modification, otherwise it won't compile).
diff mbox series

Patch

diff --git a/lib/librte_hash/rte_cuckoo_hash.c b/lib/librte_hash/rte_cuckoo_hash.c
index d2c7629..4a90049 100644
--- a/lib/librte_hash/rte_cuckoo_hash.c
+++ b/lib/librte_hash/rte_cuckoo_hash.c
@@ -133,13 +133,13 @@  rte_hash_create(const struct rte_hash_parameters *params)
 		 * except for the first cache
 		 */
 		num_key_slots = params->entries + (RTE_MAX_LCORE - 1) *
-					LCORE_CACHE_SIZE + 1;
+					(LCORE_CACHE_SIZE - 1) + 1;
 	else
 		num_key_slots = params->entries + 1;
 
 	snprintf(ring_name, sizeof(ring_name), "HT_%s", params->name);
 	/* Create ring (Dummy slot index is not enqueued) */
-	r = rte_ring_create(ring_name, rte_align32pow2(num_key_slots - 1),
+	r = rte_ring_create(ring_name, rte_align32pow2(num_key_slots),
 			params->socket_id, 0);
 	if (r == NULL) {
 		RTE_LOG(ERR, HASH, "memory allocation failed\n");
@@ -293,7 +293,7 @@  rte_hash_create(const struct rte_hash_parameters *params)
 	}
 
 	/* Populate free slots ring. Entry zero is reserved for key misses. */
-	for (i = 1; i < params->entries + 1; i++)
+	for (i = 1; i < num_key_slots; i++)
 		rte_ring_sp_enqueue(r, (void *)((uintptr_t) i));
 
 	te->data = (void *) h;
@@ -412,7 +412,7 @@  void
 rte_hash_reset(struct rte_hash *h)
 {
 	void *ptr;
-	unsigned i;
+	uint32_t tot_ring_cnt, i;
 
 	if (h == NULL)
 		return;
@@ -426,7 +426,13 @@  rte_hash_reset(struct rte_hash *h)
 		rte_pause();
 
 	/* Repopulate the free slots ring. Entry zero is reserved for key misses */
-	for (i = 1; i < h->entries + 1; i++)
+	if (h->multi_writer_support)
+		tot_ring_cnt = h->entries + (RTE_MAX_LCORE - 1) *
+					(LCORE_CACHE_SIZE - 1);
+	else
+		tot_ring_cnt = h->entries;
+
+	for (i = 1; i < tot_ring_cnt + 1; i++)
 		rte_ring_sp_enqueue(h->free_slots, (void *)((uintptr_t) i));
 
 	if (h->multi_writer_support) {