unordered_map,unordered_set: Increase excess size

Author: stotko

src/stdgpu/impl/unordered_base_detail.cuh

@@ -1203,9 +1203,9 @@ unordered_base<Key, Value, KeyFromValue, Hash, KeyEqual, Allocator>::createDevic
  bit_ceil(static_cast<std::size_t>(std::ceil(static_cast<float>(capacity) / default_max_load_factor()))));
 
  // excess count is estimated by the expected collision count:
- // - Conservatively lower the amount since entries falling into regular buckets are already included here
+ // - Keep the amount although it also counts bucket elements as this is based on assuming a uniform distribution
  // - Increase amount by 1 since insertion expects a non-empty excess list also in case of no collision
- index_t excess_count = expected_collisions(bucket_count, capacity) * 2 / 3 + 1;
+ index_t excess_count = expected_collisions(bucket_count, capacity) + 1;
 
  index_t total_count = bucket_count + excess_count;
 

tests/stdgpu/unordered_datastructure.inc

@@ -1430,7 +1430,7 @@ TEST_F(STDGPU_UNORDERED_DATASTRUCTURE_TEST_CLASS, insert_multiple_while_full)
 
 TEST_F(STDGPU_UNORDERED_DATASTRUCTURE_TEST_CLASS, insert_while_excess_empty)
 {
- test_unordered_datastructure tiny_hash_datastructure = test_unordered_datastructure::createDeviceObject(2);
+ test_unordered_datastructure tiny_hash_datastructure = test_unordered_datastructure::createDeviceObject(1);
 
  // Fill tiny hash table
  const test_unordered_datastructure::key_type position_1(1, 2, 3);
@@ -1592,7 +1592,7 @@ TEST_F(STDGPU_UNORDERED_DATASTRUCTURE_TEST_CLASS, insert_parallel_while_one_free
 
 TEST_F(STDGPU_UNORDERED_DATASTRUCTURE_TEST_CLASS, insert_parallel_while_excess_empty)
 {
- test_unordered_datastructure tiny_hash_datastructure = test_unordered_datastructure::createDeviceObject(2);
+ test_unordered_datastructure tiny_hash_datastructure = test_unordered_datastructure::createDeviceObject(1);
 
  // Fill tiny hash table
  const test_unordered_datastructure::key_type position_1(1, 2, 3);
@@ -1688,7 +1688,7 @@ TEST_F(STDGPU_UNORDERED_DATASTRUCTURE_TEST_CLASS, emplace_parallel_while_one_fre
 
 TEST_F(STDGPU_UNORDERED_DATASTRUCTURE_TEST_CLASS, emplace_parallel_while_excess_empty)
 {
- test_unordered_datastructure tiny_hash_datastructure = test_unordered_datastructure::createDeviceObject(2);
+ test_unordered_datastructure tiny_hash_datastructure = test_unordered_datastructure::createDeviceObject(1);
 
  // Fill tiny hash table
  const test_unordered_datastructure::key_type position_1(1, 2, 3);