On 11/22/2011 06:11 PM, Mathieu Desnoyers wrote: > arguemnt -> argument > > I think we need to discuss the semantic of max_size: here, you propose > that max_size is just the number of buckets, but it does not limit the > ability of the table to contain more elements than max_size. > > IMHO, it would be nice to have max_size limit the number of elements > that the table can accept, e.g. ensuring that insertion fails if the > number of elements gets over the max_size threshold. It might not need > to be an exact thing though, just giving an approximated upper limit > might be fine (using the split-counters), as long as it is documented.
documented: "max_size: the max size of buckets for future growing" Is max_bucket_size better? and min_alloc_size need to be changed to min_alloc_bucket_size? I'm not planing to add "max_size" for the number of elements in this round or near future. Thanks, Lai > > Thanks, > > Mathieu > > * Lai Jiangshan ([email protected]) wrote: >> 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 >> > _______________________________________________ ltt-dev mailing list [email protected] http://lists.casi.polymtl.ca/cgi-bin/mailman/listinfo/ltt-dev
