Ruby 2.2 GC

$ RUBY_GC_HEAP_INIT_SLOTS=600000 ruby gc-test.rb 1
ruby version 2.2.0
 proces   pid log          priv_dirty shared_dirty
 Parent  2368 post alloc           31          0
{:count=>3,
 :heap_allocated_pages=>1470,
 :heap_sorted_length=>2566,
 :heap_allocatable_pages=>1095,
 :heap_available_slots=>599162,
 :heap_live_slots=>508082,
 :heap_free_slots=>91080,
 :heap_final_slots=>0,
 :heap_marked_slots=>508036,
 :heap_swept_slots=>487752,
 :heap_eden_pages=>1341,
 :heap_tomb_pages=>129,
 :total_allocated_pages=>1470,
 :total_freed_pages=>0,
 :total_allocated_objects=>548526,
 :total_freed_objects=>40444,
 :malloc_increase_bytes=>6992,
 :malloc_increase_bytes_limit=>16777216,
 :minor_gc_count=>0,
 :major_gc_count=>3,
 :remembered_wb_unprotected_objects=>161,
 :remembered_wb_unprotected_objects_limit=>322,
 :old_objects=>507852,
 :old_objects_limit=>1015704,
 :oldmalloc_increase_bytes=>7440,
 :oldmalloc_increase_bytes_limit=>16777216}
 Parent  2368 4 fork                1         34
 Child   2370 4 initial             1         34
{:count=>4,
 :heap_allocated_pages=>1470,
 :heap_sorted_length=>2566,
 :heap_allocatable_pages=>1095,
 :heap_available_slots=>599162,
 :heap_live_slots=>508088,
 :heap_free_slots=>91074,
 :heap_final_slots=>0,
 :heap_marked_slots=>508086,
 :heap_swept_slots=>485257,
 :heap_eden_pages=>1340,
 :heap_tomb_pages=>130,
 :total_allocated_pages=>1470,
 :total_freed_pages=>0,
 :total_allocated_objects=>550196,
 :total_freed_objects=>42108,
 :malloc_increase_bytes=>1104,
 :malloc_increase_bytes_limit=>16777216,
 :minor_gc_count=>1,
 :major_gc_count=>3,
 :remembered_wb_unprotected_objects=>162,
 :remembered_wb_unprotected_objects_limit=>322,
 :old_objects=>507895,
 :old_objects_limit=>1015704,
 :oldmalloc_increase_bytes=>1552,
 :oldmalloc_increase_bytes_limit=>16777216}
 Child   2370 8 empty GC            2         32