[dpdk-stable] patch 'hash: fix key slot size accuracy' has been queued to LTS release 17.11.4

[Yongseok Koh]

Hi,

FYI, your patch has been queued to LTS release 17.11.4

Note it hasn't been pushed to http://dpdk.org/browse/dpdk-stable yet.
It will be pushed if I get no objections before 07/28/18. So please
shout if anyone has objections.

Thanks.

Yongseok

---
>From 9dc73dd86775a6c5980f5c9cf69398c292bd920c Mon Sep 17 00:00:00 2001
From: Yipeng Wang <yipeng1.wang at intel.com>
Date: Tue, 10 Jul 2018 09:59:56 -0700
Subject: [PATCH] hash: fix key slot size accuracy

[ upstream commit 575a48c961f47f1078bd1ceacf8484fb1038f7f8 ]

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 at intel.com>
Acked-by: Pablo de Lara <pablo.de.lara.guarch at intel.com>
---
 lib/librte_hash/rte_cuckoo_hash.c | 16 +++++++++++-----
 1 file changed, 11 insertions(+), 5 deletions(-)

diff --git a/lib/librte_hash/rte_cuckoo_hash.c b/lib/librte_hash/rte_cuckoo_hash.c
index bc7a9d998..9be514dcc 100644
--- a/lib/librte_hash/rte_cuckoo_hash.c
+++ b/lib/librte_hash/rte_cuckoo_hash.c
@@ -154,13 +154,13 @@ 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");
@@ -312,7 +312,7 @@ rte_hash_create(const struct rte_hash_parameters *params)
 		h->add_key = ADD_KEY_SINGLEWRITER;
 
 	/* 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;
@@ -394,7 +394,7 @@ void
 rte_hash_reset(struct rte_hash *h)
 {
 	void *ptr;
-	unsigned i;
+	uint32_t tot_ring_cnt, i;
 
 	if (h == NULL)
 		return;
@@ -407,7 +407,13 @@ 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->hw_trans_mem_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->hw_trans_mem_support) {
-- 
2.11.0