Merge branch 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel...

[cascardo/linux.git] / lib / rhashtable.c

diff --git a/lib/rhashtable.c b/lib/rhashtable.c
index 7b36e4d..081be3b 100644 (file)
--- a/lib/rhashtable.c
+++ b/lib/rhashtable.c
@@ -54,7 +54,7 @@ static u32 __hashfn(const struct rhashtable *ht, const void *key,
 
 /**
  * rhashtable_hashfn - compute hash for key of given length
- * @ht:                hash table to compuate for
+ * @ht:                hash table to compute for
  * @key:       pointer to key
  * @len:       length of key
  *
@@ -85,7 +85,7 @@ static u32 obj_hashfn(const struct rhashtable *ht, const void *ptr, u32 hsize)
 
 /**
  * rhashtable_obj_hashfn - compute hash for hashed object
- * @ht:                hash table to compuate for
+ * @ht:                hash table to compute for
  * @ptr:       pointer to hashed object
  *
  * Computes the hash value using the hash function `hashfn` respectively
@@ -297,7 +297,7 @@ int rhashtable_shrink(struct rhashtable *ht, gfp_t flags)
 
        ASSERT_RHT_MUTEX(ht);
 
-       if (tbl->size <= HASH_MIN_SIZE)
+       if (ht->shift <= ht->p.min_shift)
                return 0;
 
        ntbl = bucket_table_alloc(tbl->size / 2, flags);
@@ -505,9 +505,10 @@ void *rhashtable_lookup_compare(const struct rhashtable *ht, u32 hash,
 }
 EXPORT_SYMBOL_GPL(rhashtable_lookup_compare);
 
-static size_t rounded_hashtable_size(unsigned int nelem)
+static size_t rounded_hashtable_size(struct rhashtable_params *params)
 {
-       return max(roundup_pow_of_two(nelem * 4 / 3), HASH_MIN_SIZE);
+       return max(roundup_pow_of_two(params->nelem_hint * 4 / 3),
+                  1UL << params->min_shift);
 }
 
 /**
@@ -565,8 +566,11 @@ int rhashtable_init(struct rhashtable *ht, struct rhashtable_params *params)
            (!params->key_len && !params->obj_hashfn))
                return -EINVAL;
 
+       params->min_shift = max_t(size_t, params->min_shift,
+                                 ilog2(HASH_MIN_SIZE));
+
        if (params->nelem_hint)
-               size = rounded_hashtable_size(params->nelem_hint);
+               size = rounded_hashtable_size(params);
 
        tbl = bucket_table_alloc(size, GFP_KERNEL);
        if (tbl == NULL)
@@ -588,13 +592,13 @@ EXPORT_SYMBOL_GPL(rhashtable_init);
  * rhashtable_destroy - destroy hash table
  * @ht:                the hash table to destroy
  *
- * Frees the bucket array.
+ * Frees the bucket array. This function is not rcu safe, therefore the caller
+ * has to make sure that no resizing may happen by unpublishing the hashtable
+ * and waiting for the quiescent cycle before releasing the bucket array.
  */
 void rhashtable_destroy(const struct rhashtable *ht)
 {
-       const struct bucket_table *tbl = rht_dereference(ht->tbl, ht);
-
-       bucket_table_free(tbl);
+       bucket_table_free(ht->tbl);
 }
 EXPORT_SYMBOL_GPL(rhashtable_destroy);