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

*** 278,287 ****
--- 278,294 ----
        // Don't check if the size_policy is ready here.  Let
        // the size_policy check that internally.
        if (UseAdaptiveGenerationSizePolicyAtMajorCollection &&
            ((gc_cause != GCCause::_java_lang_system_gc) ||
              UseAdaptiveSizePolicyWithSystemGC)) {
+         // Swap the survivor spaces if from_space is empty
+         if (UseAdaptiveSizePolicyResizeYoungGenAtMajorCollection &&
+             young_gen->from_space()->is_empty()) {
+           young_gen->from_space()->clear(SpaceDecorator::Mangle);
+           young_gen->swap_spaces();
+         }
+ 
          // Calculate optimal free space amounts
          assert(young_gen->max_size() >
            young_gen->from_space()->capacity_in_bytes() +
            young_gen->to_space()->capacity_in_bytes(),
            "Sizes of space in young gen are out-of-bounds");
*** 316,331 ****
  
          size_policy->decay_supplemental_growth(true /* full gc*/);
  
          heap->resize_old_gen(size_policy->calculated_old_free_size_in_bytes());
  
!         // Don't resize the young generation at an major collection.  A
!         // desired young generation size may have been calculated but
!         // resizing the young generation complicates the code because the
!         // resizing of the old generation may have moved the boundary
!         // between the young generation and the old generation.  Let the
!         // young generation resizing happen at the minor collections.
        }
        if (PrintAdaptiveSizePolicy) {
          gclog_or_tty->print_cr("AdaptiveSizeStop: collection: %d ",
                         heap->total_collections());
        }
--- 323,336 ----
  
          size_policy->decay_supplemental_growth(true /* full gc*/);
  
          heap->resize_old_gen(size_policy->calculated_old_free_size_in_bytes());
  
!         if (UseAdaptiveSizePolicyResizeYoungGenAtMajorCollection) {
!           heap->resize_young_gen(size_policy->calculated_eden_size_in_bytes(),
!                                  size_policy->calculated_survivor_size_in_bytes());
!         }
        }
        if (PrintAdaptiveSizePolicy) {
          gclog_or_tty->print_cr("AdaptiveSizeStop: collection: %d ",
                         heap->total_collections());
        }