--- old/src/hotspot/share/gc/parallel/parallelScavengeHeap.cpp	2018-09-19 15:53:47.710967900 -0700
+++ new/src/hotspot/share/gc/parallel/parallelScavengeHeap.cpp	2018-09-19 15:53:47.086438900 -0700
@@ -25,6 +25,7 @@
 #include "precompiled.hpp"
 #include "code/codeCache.hpp"
 #include "gc/parallel/adjoiningGenerations.hpp"
+#include "gc/parallel/adjoiningGenerationsForHeteroHeap.hpp"
 #include "gc/parallel/adjoiningVirtualSpaces.hpp"
 #include "gc/parallel/gcTaskManager.hpp"
 #include "gc/parallel/generationSizer.hpp"
@@ -58,7 +59,11 @@
 GCTaskManager* ParallelScavengeHeap::_gc_task_manager = NULL;
 
 jint ParallelScavengeHeap::initialize() {
-  const size_t heap_size = _collector_policy->max_heap_byte_size();
+  size_t heap_size = _collector_policy->max_heap_byte_size();
+
+  if (AllocateOldGenAt != NULL && UseAdaptiveGCBoundary) {
+    heap_size = AdjoiningGenerationsForHeteroHeap::required_reserved_memory(_collector_policy);
+  }
 
   ReservedSpace heap_rs = Universe::reserve_heap(heap_size, _collector_policy->heap_alignment());
 
@@ -86,7 +91,13 @@
   double max_gc_pause_sec = ((double) MaxGCPauseMillis)/1000.0;
   double max_gc_minor_pause_sec = ((double) MaxGCMinorPauseMillis)/1000.0;
 
-  _gens = new AdjoiningGenerations(heap_rs, _collector_policy, generation_alignment());
+  if (AllocateOldGenAt != NULL && UseAdaptiveGCBoundary) {
+    _gens = new AdjoiningGenerationsForHeteroHeap(heap_rs, _collector_policy->max_heap_byte_size() /* total_size_limit */,
+                                                  _collector_policy, generation_alignment());
+  }
+  else {
+    _gens = new AdjoiningGenerations(heap_rs, _collector_policy, generation_alignment());
+  }
 
   _old_gen = _gens->old_gen();
   _young_gen = _gens->young_gen();
@@ -104,7 +115,7 @@
                              GCTimeRatio
                              );
 
-  assert(!UseAdaptiveGCBoundary ||
+  assert(AllocateOldGenAt != NULL || !UseAdaptiveGCBoundary ||
     (old_gen()->virtual_space()->high_boundary() ==
      young_gen()->virtual_space()->low_boundary()),
     "Boundaries must meet");