diff -r 4a57933cebfa -r f8fd0bcc60af hotspot/src/share/vm/gc/cms/compactibleFreeListSpace.hpp
--- a/hotspot/src/share/vm/gc/cms/compactibleFreeListSpace.hpp	Thu Apr 07 15:33:25 2016 -0700
+++ b/hotspot/src/share/vm/gc/cms/compactibleFreeListSpace.hpp	Thu Apr 07 15:34:21 2016 -0700
@@ -345,6 +345,8 @@
   // Support for parallelization of rescan and marking.
   const size_t rescan_task_size()  const { return _rescan_task_size;  }
   const size_t marking_task_size() const { return _marking_task_size; }
+  // Return ergonomic max size for CMSRescanMultiple and CMSConcMarkMultiple.
+  const size_t max_flag_size_for_task_size() const;
   SequentialSubTasksDone* conc_par_seq_tasks() {return &_conc_par_seq_tasks; }
   void initialize_sequential_subtasks_for_rescan(int n_threads);
   void initialize_sequential_subtasks_for_marking(int n_threads,