From 98b8ec70604065f511aea0a567b039421bc524cc Mon Sep 17 00:00:00 2001 From: Pablo de Lara Date: Fri, 22 Sep 2017 05:25:43 +0100 Subject: [PATCH] hash: fix eviction counter When adding a new entry in a hash table, there is a maximum number of evictions that can be performed. When the counter of these evictions reaches this maximum, the entry cannot be added, as it is considered that the algorithm has encountered an infinite loop. The problem with the current implementation, is that this counter was declared as a static variable. If there are multiple threads adding entries in the same table or in different tables, they should access different counters, one per core and per table. Therefore, the variable has been modified to be non-static. Fixes: 243e93a5046f ("hash: fix unlimited cuckoo path") Cc: stable@dpdk.org Signed-off-by: Pablo de Lara Acked-by: Bruce Richardson --- lib/librte_hash/rte_cuckoo_hash.c | 13 ++++++------- 1 file changed, 6 insertions(+), 7 deletions(-) diff --git a/lib/librte_hash/rte_cuckoo_hash.c b/lib/librte_hash/rte_cuckoo_hash.c index 87b25c016a..e69b911722 100644 --- a/lib/librte_hash/rte_cuckoo_hash.c +++ b/lib/librte_hash/rte_cuckoo_hash.c @@ -417,9 +417,9 @@ rte_hash_reset(struct rte_hash *h) /* Search for an entry that can be pushed to its alternative location */ static inline int -make_space_bucket(const struct rte_hash *h, struct rte_hash_bucket *bkt) +make_space_bucket(const struct rte_hash *h, struct rte_hash_bucket *bkt, + unsigned int *nr_pushes) { - static unsigned int nr_pushes; unsigned i, j; int ret; uint32_t next_bucket_idx; @@ -456,15 +456,14 @@ make_space_bucket(const struct rte_hash *h, struct rte_hash_bucket *bkt) break; /* All entries have been pushed, so entry cannot be added */ - if (i == RTE_HASH_BUCKET_ENTRIES || nr_pushes > RTE_HASH_MAX_PUSHES) + if (i == RTE_HASH_BUCKET_ENTRIES || ++(*nr_pushes) > RTE_HASH_MAX_PUSHES) return -ENOSPC; /* Set flag to indicate that this entry is going to be pushed */ bkt->flag[i] = 1; - nr_pushes++; /* Need room in alternative bucket to insert the pushed entry */ - ret = make_space_bucket(h, next_bkt[i]); + ret = make_space_bucket(h, next_bkt[i], nr_pushes); /* * After recursive function. * Clear flags and insert the pushed entry @@ -472,7 +471,6 @@ make_space_bucket(const struct rte_hash *h, struct rte_hash_bucket *bkt) * or return error */ bkt->flag[i] = 0; - nr_pushes = 0; if (ret >= 0) { next_bkt[i]->sig_alt[ret] = bkt->sig_current[i]; next_bkt[i]->sig_current[ret] = bkt->sig_alt[i]; @@ -515,6 +513,7 @@ __rte_hash_add_key_with_hash(const struct rte_hash *h, const void *key, unsigned n_slots; unsigned lcore_id; struct lcore_cache *cached_free_slots = NULL; + unsigned int nr_pushes = 0; if (h->add_key == ADD_KEY_MULTIWRITER) rte_spinlock_lock(h->multiwriter_lock); @@ -648,7 +647,7 @@ __rte_hash_add_key_with_hash(const struct rte_hash *h, const void *key, * if successful or return error and * store the new slot back in the ring */ - ret = make_space_bucket(h, prim_bkt); + ret = make_space_bucket(h, prim_bkt, &nr_pushes); if (ret >= 0) { prim_bkt->sig_current[ret] = sig; prim_bkt->sig_alt[ret] = alt_hash; -- 2.20.1