rhashtable: Introduce max_size/min_size
This patch adds the parameters max_size and min_size which are
meant to replace max_shift and min_shift.
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/lib/rhashtable.c b/lib/rhashtable.c
index 0974003..c4061bb 100644
--- a/lib/rhashtable.c
+++ b/lib/rhashtable.c
@@ -27,7 +27,7 @@
#include <linux/err.h>
#define HASH_DEFAULT_SIZE 64UL
-#define HASH_MIN_SIZE 4UL
+#define HASH_MIN_SIZE 4U
#define BUCKET_LOCKS_PER_CPU 128UL
/* Base bits plus 1 bit for nulls marker */
@@ -188,7 +188,8 @@
{
/* Expand table when exceeding 75% load */
return atomic_read(&ht->nelems) > (tbl->size / 4 * 3) &&
- (!ht->p.max_shift || tbl->size < (1 << ht->p.max_shift));
+ (!ht->p.max_shift || tbl->size < (1 << ht->p.max_shift)) &&
+ (!ht->p.max_size || tbl->size < ht->p.max_size);
}
/**
@@ -201,7 +202,8 @@
{
/* Shrink table beneath 30% load */
return atomic_read(&ht->nelems) < (tbl->size * 3 / 10) &&
- tbl->size > (1 << ht->p.min_shift);
+ tbl->size > (1 << ht->p.min_shift) &&
+ tbl->size > ht->p.min_size;
}
static int rhashtable_rehash_one(struct rhashtable *ht, unsigned old_hash)
@@ -873,7 +875,8 @@
static size_t rounded_hashtable_size(struct rhashtable_params *params)
{
return max(roundup_pow_of_two(params->nelem_hint * 4 / 3),
- 1UL << params->min_shift);
+ max(1UL << params->min_shift,
+ (unsigned long)params->min_size));
}
/**
@@ -935,6 +938,7 @@
params->min_shift = max_t(size_t, params->min_shift,
ilog2(HASH_MIN_SIZE));
+ params->min_size = max(params->min_size, HASH_MIN_SIZE);
if (params->nelem_hint)
size = rounded_hashtable_size(params);