* Lai Jiangshan ([email protected]) wrote: > 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.
maybe max_nr_buckets then ? nr_ seems to be more descriptive than "size" in this context, because "size" could lead to some confusion, leading to think that we would be specifying the size of a bucket rather than actually specifying the number of buckets. Seems reasonable ? Thanks, Mathieu > > 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 > -- Mathieu Desnoyers Operating System Efficiency R&D Consultant EfficiOS Inc. http://www.efficios.com _______________________________________________ ltt-dev mailing list [email protected] http://lists.casi.polymtl.ca/cgi-bin/mailman/listinfo/ltt-dev
