src/share/vm/gc_implementation/parallelScavenge/psScavenge.cpp

rev 5803 : 8028391: Make the Min/MaxHeapFreeRatio flags manageable
Summary: Made the flags Min- and MaxHeapFreeRatio manageable, and implemented support for these flags in ParallalGC.
Reviewed-by: sla, mgerdin, brutisso

*** 527,538 ****
            counters->update_survived(survived);
            counters->update_promoted(promoted);
            counters->update_survivor_overflowed(_survivor_overflow);
          }
  
          size_t survivor_limit =
!           size_policy->max_survivor_size(young_gen->max_size());
          _tenuring_threshold =
            size_policy->compute_survivor_space_size_and_threshold(
                                                             _survivor_overflow,
                                                             _tenuring_threshold,
                                                             survivor_limit);
--- 527,549 ----
            counters->update_survived(survived);
            counters->update_promoted(promoted);
            counters->update_survivor_overflowed(_survivor_overflow);
          }
  
+         size_t max_young_size = young_gen->max_size();
+ 
+         // Deciding a free ratio in the young generation is tricky, so if
+         // MinHeapFreeRatio or MaxHeapFreeRatio are in use (implicating
+         // that the old generation size may have been limited because of them) we
+         // should then limit our young generation size using NewRatio to have it
+         // follow the old generation size.
+         if (MinHeapFreeRatio != 0 || MaxHeapFreeRatio != 100) {
+           max_young_size = MIN2(old_gen->capacity_in_bytes() / NewRatio, young_gen->max_size());
+         }
+ 
          size_t survivor_limit =
!           size_policy->max_survivor_size(max_young_size);
          _tenuring_threshold =
            size_policy->compute_survivor_space_size_and_threshold(
                                                             _survivor_overflow,
                                                             _tenuring_threshold,
                                                             survivor_limit);
*** 551,562 ****
          }
  
          // Do call at minor collections?
          // Don't check if the size_policy is ready at this
          // level.  Let the size_policy check that internally.
!         if (UseAdaptiveSizePolicy &&
!             UseAdaptiveGenerationSizePolicyAtMinorCollection &&
              ((gc_cause != GCCause::_java_lang_system_gc) ||
                UseAdaptiveSizePolicyWithSystemGC)) {
  
            // Calculate optimial free space amounts
            assert(young_gen->max_size() >
--- 562,572 ----
          }
  
          // Do call at minor collections?
          // Don't check if the size_policy is ready at this
          // level.  Let the size_policy check that internally.
!         if (UseAdaptiveGenerationSizePolicyAtMinorCollection &&
              ((gc_cause != GCCause::_java_lang_system_gc) ||
                UseAdaptiveSizePolicyWithSystemGC)) {
  
            // Calculate optimial free space amounts
            assert(young_gen->max_size() >
*** 566,576 ****
  
            size_t young_live = young_gen->used_in_bytes();
            size_t eden_live = young_gen->eden_space()->used_in_bytes();
            size_t cur_eden = young_gen->eden_space()->capacity_in_bytes();
            size_t max_old_gen_size = old_gen->max_gen_size();
!           size_t max_eden_size = young_gen->max_size() -
              young_gen->from_space()->capacity_in_bytes() -
              young_gen->to_space()->capacity_in_bytes();
  
            // Used for diagnostics
            size_policy->clear_generation_free_space_flags();
--- 576,586 ----
  
            size_t young_live = young_gen->used_in_bytes();
            size_t eden_live = young_gen->eden_space()->used_in_bytes();
            size_t cur_eden = young_gen->eden_space()->capacity_in_bytes();
            size_t max_old_gen_size = old_gen->max_gen_size();
!           size_t max_eden_size = max_young_size -
              young_gen->from_space()->capacity_in_bytes() -
              young_gen->to_space()->capacity_in_bytes();
  
            // Used for diagnostics
            size_policy->clear_generation_free_space_flags();