Signed-off-by: Lai Jiangshan <[email protected]>
---
rculfhash.c | 17 +++++++++++++++++
tests/test_urcu_hash.c | 2 +-
urcu/rculfhash.h | 9 ++++++---
3 files changed, 24 insertions(+), 4 deletions(-)
diff --git a/rculfhash.c b/rculfhash.c
index 2df133c..b7be893 100644
--- a/rculfhash.c
+++ b/rculfhash.c
@@ -266,6 +266,7 @@ struct cds_lfht {
struct rcu_table t;
unsigned long min_alloc_order;
unsigned long min_alloc_size;
+ unsigned long max_size;
int flags;
/*
* We need to put the work threads offline (QSBR) when taking this
@@ -1351,6 +1352,7 @@ void cds_lfht_create_bucket(struct cds_lfht *ht, unsigned
long size)
struct cds_lfht *_cds_lfht_new(unsigned long init_size,
unsigned long min_alloc_size,
+ unsigned long max_size,
int flags,
void (*cds_lfht_call_rcu)(struct rcu_head *head,
void (*func)(struct rcu_head *head)),
@@ -1369,11 +1371,22 @@ struct cds_lfht *_cds_lfht_new(unsigned long init_size,
/* min_alloc_size must be power of two */
if (!min_alloc_size || (min_alloc_size & (min_alloc_size - 1)))
return NULL;
+
/* init_size must be power of two */
if (!init_size || (init_size & (init_size - 1)))
return NULL;
+
+ if (!max_size)
+ max_size = 1UL << (MAX_TABLE_ORDER - 1);
+
+ /* max_size must be power of two */
+ if (!max_size || (max_size & (max_size - 1)))
+ return NULL;
+
min_alloc_size = max(min_alloc_size, MIN_TABLE_SIZE);
init_size = max(init_size, MIN_TABLE_SIZE);
+ max_size = max(max_size, min_alloc_size);
+ init_size = min(init_size, max_size);
ht = calloc(1, sizeof(struct cds_lfht));
assert(ht);
ht->flags = flags;
@@ -1393,6 +1406,7 @@ struct cds_lfht *_cds_lfht_new(unsigned long init_size,
ht->t.resize_target = 1UL << order;
ht->min_alloc_size = min_alloc_size;
ht->min_alloc_order = get_count_order_ulong(min_alloc_size);
+ ht->max_size = max_size;
cds_lfht_create_bucket(ht, 1UL << order);
ht->t.size = 1UL << order;
return ht;
@@ -1752,6 +1766,7 @@ void resize_target_update_count(struct cds_lfht *ht,
unsigned long count)
{
count = max(count, MIN_TABLE_SIZE);
+ count = min(count, ht->max_size);
uatomic_set(&ht->t.resize_target, count);
}
@@ -1809,6 +1824,7 @@ void cds_lfht_resize_lazy_grow(struct cds_lfht *ht,
unsigned long size, int grow
{
unsigned long target_size = size << growth;
+ target_size = min(target_size, ht->max_size);
if (resize_target_grow(ht, target_size) >= target_size)
return;
@@ -1827,6 +1843,7 @@ void cds_lfht_resize_lazy_count(struct cds_lfht *ht,
unsigned long size,
if (!(ht->flags & CDS_LFHT_AUTO_RESIZE))
return;
count = max(count, MIN_TABLE_SIZE);
+ count = min(count, ht->max_size);
if (count == size)
return; /* Already the right size, no resize needed */
if (count > size) { /* lazy grow */
diff --git a/tests/test_urcu_hash.c b/tests/test_urcu_hash.c
index b9e3e81..2961177 100644
--- a/tests/test_urcu_hash.c
+++ b/tests/test_urcu_hash.c
@@ -967,7 +967,7 @@ int main(int argc, char **argv)
* thread from the point of view of resize.
*/
rcu_register_thread();
- test_ht = cds_lfht_new(init_hash_size, min_hash_alloc_size,
+ test_ht = cds_lfht_new(init_hash_size, min_hash_alloc_size, (1UL << 18),
(opt_auto_resize ? CDS_LFHT_AUTO_RESIZE : 0) |
CDS_LFHT_ACCOUNTING, NULL);
ret = populate_hash();
diff --git a/urcu/rculfhash.h b/urcu/rculfhash.h
index c13d3df..2eefd2c 100644
--- a/urcu/rculfhash.h
+++ b/urcu/rculfhash.h
@@ -98,6 +98,7 @@ enum {
*/
struct cds_lfht *_cds_lfht_new(unsigned long init_size,
unsigned long min_alloc_size,
+ unsigned long max_size,
int flags,
void (*cds_lfht_call_rcu)(struct rcu_head *head,
void (*func)(struct rcu_head *head)),
@@ -112,8 +113,9 @@ struct cds_lfht *_cds_lfht_new(unsigned long init_size,
/*
* cds_lfht_new - allocate a hash table.
- * @init_size: number of nodes to allocate initially. Must be power of two.
- * @min_alloc_size: the smallest allocation size to use. Must be power of two.
+ * @init_size: number of buckets to allocate initially. Must be power of two.
+ * @min_alloc_size: the smallest allocation buckets size to use. Must be power
of two.
+ * @max_size: the max size of buckets for future growing. Must be power of two.
* @flags: hash table creation flags (can be combined with bitwise or: '|').
* 0: no flags.
* CDS_LFHT_AUTO_RESIZE: automatically resize hash table.
@@ -134,10 +136,11 @@ struct cds_lfht *_cds_lfht_new(unsigned long init_size,
static inline
struct cds_lfht *cds_lfht_new(unsigned long init_size,
unsigned long min_alloc_size,
+ unsigned long max_size,
int flags,
pthread_attr_t *attr)
{
- return _cds_lfht_new(init_size, min_alloc_size, flags,
+ return _cds_lfht_new(init_size, min_alloc_size, max_size, flags,
call_rcu, synchronize_rcu, rcu_read_lock,
rcu_read_unlock, rcu_thread_offline,
rcu_thread_online, rcu_register_thread,
--
1.7.4.4
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