--- a/hotspot/agent/src/share/classes/sun/jvm/hotspot/gc/g1/G1Allocator.java	Thu Jul 23 08:45:25 2015 +0200
+++ /dev/null	Thu Jan 01 00:00:00 1970 +0000
@@ -1,40 +0,0 @@
-package sun.jvm.hotspot.gc.g1;
-
-import java.util.Observable;
-import java.util.Observer;
-
-import sun.jvm.hotspot.debugger.Address;
-import sun.jvm.hotspot.runtime.VM;
-import sun.jvm.hotspot.runtime.VMObject;
-import sun.jvm.hotspot.types.CIntegerField;
-import sun.jvm.hotspot.types.Type;
-import sun.jvm.hotspot.types.TypeDataBase;
-
-public class G1Allocator extends VMObject {
-
-  //size_t _summary_bytes_used;
-  static private CIntegerField summaryBytesUsedField;
-
-  static {
-    VM.registerVMInitializedObserver(new Observer() {
-      public void update(Observable o, Object data) {
-        initialize(VM.getVM().getTypeDataBase());
-      }
-    });
-  }
-
-  static private synchronized void initialize(TypeDataBase db) {
-    Type type = db.lookupType("G1Allocator");
-
-    summaryBytesUsedField = type.getCIntegerField("_summary_bytes_used");
-  }
-
-  public long getSummaryBytes() {
-    return summaryBytesUsedField.getValue(addr);
-  }
-
-  public G1Allocator(Address addr) {
-    super(addr);
-
-  }
-}

--- a/hotspot/agent/src/share/classes/sun/jvm/hotspot/gc/g1/G1CollectedHeap.java	Thu Jul 23 08:45:25 2015 +0200
+++ b/hotspot/agent/src/share/classes/sun/jvm/hotspot/gc/g1/G1CollectedHeap.java	Thu Jul 23 11:14:24 2015 +0200
@@ -36,6 +36,7 @@
 import sun.jvm.hotspot.runtime.VM;
 import sun.jvm.hotspot.runtime.VMObjectFactory;
 import sun.jvm.hotspot.types.AddressField;
+import sun.jvm.hotspot.types.CIntegerField;
 import sun.jvm.hotspot.types.Type;
 import sun.jvm.hotspot.types.TypeDataBase;
 
@@ -46,8 +47,8 @@
     static private long hrmFieldOffset;
     // MemRegion _g1_reserved;
     static private long g1ReservedFieldOffset;
-    // G1Allocator* _allocator
-    static private AddressField g1Allocator;
+    // size_t _summary_bytes_used;
+    static private CIntegerField summaryBytesUsedField;
     // G1MonitoringSupport* _g1mm;
     static private AddressField g1mmField;
     // HeapRegionSet _old_set;
@@ -67,7 +68,7 @@
         Type type = db.lookupType("G1CollectedHeap");
 
         hrmFieldOffset = type.getField("_hrm").getOffset();
-        g1Allocator = type.getAddressField("_allocator");
+        summaryBytesUsedField = type.getCIntegerField("_summary_bytes_used");
         g1mmField = type.getAddressField("_g1mm");
         oldSetFieldOffset = type.getField("_old_set").getOffset();
         humongousSetFieldOffset = type.getField("_humongous_set").getOffset();
@@ -78,7 +79,7 @@
     }
 
     public long used() {
-        return allocator().getSummaryBytes();
+        return summaryBytesUsedField.getValue(addr);
     }
 
     public long n_regions() {
@@ -96,11 +97,6 @@
         return (G1MonitoringSupport) VMObjectFactory.newObject(G1MonitoringSupport.class, g1mmAddr);
     }
 
-    public G1Allocator allocator() {
-        Address g1AllocatorAddr = g1Allocator.getValue(addr);
-        return (G1Allocator) VMObjectFactory.newObject(G1Allocator.class, g1AllocatorAddr);
-    }
-
     public HeapRegionSetBase oldSet() {
         Address oldSetAddr = addr.addOffsetTo(oldSetFieldOffset);
         return (HeapRegionSetBase) VMObjectFactory.newObject(HeapRegionSetBase.class,

--- a/hotspot/src/share/vm/gc/g1/g1Allocator.hpp	Thu Jul 23 08:45:25 2015 +0200
+++ b/hotspot/src/share/vm/gc/g1/g1Allocator.hpp	Thu Jul 23 11:14:24 2015 +0200
@@ -39,13 +39,8 @@
 protected:
   G1CollectedHeap* _g1h;
 
-  // Outside of GC pauses, the number of bytes used in all regions other
-  // than the current allocation region.
-  size_t _summary_bytes_used;
-
 public:
-  G1Allocator(G1CollectedHeap* heap) :
-    _g1h(heap), _summary_bytes_used(0) { }
+  G1Allocator(G1CollectedHeap* heap) : _g1h(heap) { }
 
   static G1Allocator* create_allocator(G1CollectedHeap* g1h);
 
@@ -59,32 +54,13 @@
   virtual MutatorAllocRegion*    mutator_alloc_region(AllocationContext_t context) = 0;
   virtual SurvivorGCAllocRegion* survivor_gc_alloc_region(AllocationContext_t context) = 0;
   virtual OldGCAllocRegion*      old_gc_alloc_region(AllocationContext_t context) = 0;
-  virtual size_t                 used() = 0;
+  virtual size_t                 used_in_alloc_regions() = 0;
   virtual bool                   is_retained_old_region(HeapRegion* hr) = 0;
 
   void                           reuse_retained_old_region(EvacuationInfo& evacuation_info,
                                                            OldGCAllocRegion* old,
                                                            HeapRegion** retained);
 
-  size_t used_unlocked() const {
-    return _summary_bytes_used;
-  }
-
-  void increase_used(size_t bytes) {
-    _summary_bytes_used += bytes;
-  }
-
-  void decrease_used(size_t bytes) {
-    assert(_summary_bytes_used >= bytes,
-           err_msg("invariant: _summary_bytes_used: " SIZE_FORMAT " should be >= bytes: " SIZE_FORMAT,
-               _summary_bytes_used, bytes));
-    _summary_bytes_used -= bytes;
-  }
-
-  void set_used(size_t bytes) {
-    _summary_bytes_used = bytes;
-  }
-
   virtual HeapRegion* new_heap_region(uint hrs_index,
                                       G1BlockOffsetSharedArray* sharedOffsetArray,
                                       MemRegion mr) {
@@ -133,10 +109,10 @@
     return &_old_gc_alloc_region;
   }
 
-  virtual size_t used() {
+  virtual size_t used_in_alloc_regions() {
     assert(Heap_lock->owner() != NULL,
            "Should be owned on this thread's behalf.");
-    size_t result = _summary_bytes_used;
+    size_t result = 0;
 
     // Read only once in case it is set to NULL concurrently
     HeapRegion* hr = mutator_alloc_region(AllocationContext::current())->get();

--- a/hotspot/src/share/vm/gc/g1/g1CollectedHeap.cpp	Thu Jul 23 08:45:25 2015 +0200
+++ b/hotspot/src/share/vm/gc/g1/g1CollectedHeap.cpp	Thu Jul 23 11:14:24 2015 +0200
@@ -632,7 +632,7 @@
   check_bitmaps("Humongous Region Allocation", first_hr);
 
   assert(first_hr->used() == word_size * HeapWordSize, "invariant");
-  _allocator->increase_used(first_hr->used());
+  increase_used(first_hr->used());
   _humongous_set.add(first_hr);
 
   return new_obj;
@@ -998,7 +998,7 @@
     if ((prev_last_region != NULL) && (start_region == prev_last_region)) {
       start_address = start_region->end();
       if (start_address > last_address) {
-        _allocator->increase_used(word_size * HeapWordSize);
+        increase_used(word_size * HeapWordSize);
         start_region->set_top(last_address + 1);
         continue;
       }
@@ -1012,7 +1012,7 @@
     if (!_hrm.allocate_containing_regions(curr_range, &commits)) {
       return false;
     }
-    _allocator->increase_used(word_size * HeapWordSize);
+    increase_used(word_size * HeapWordSize);
     if (commits != 0) {
       ergo_verbose1(ErgoHeapSizing,
                     "attempt heap expansion",
@@ -1104,7 +1104,7 @@
     if (start_address != bottom_address) {
       size_t fill_size = pointer_delta(start_address, bottom_address);
       G1CollectedHeap::fill_with_objects(bottom_address, fill_size);
-      _allocator->increase_used(fill_size * HeapWordSize);
+      increase_used(fill_size * HeapWordSize);
     }
   }
 }
@@ -1930,6 +1930,7 @@
   _free_regions_coming(false),
   _young_list(new YoungList(this)),
   _gc_time_stamp(0),
+  _summary_bytes_used(0),
   _survivor_plab_stats(YoungPLABSize, PLABWeight),
   _old_plab_stats(OldPLABSize, PLABWeight),
   _expand_heap_after_alloc_failure(true),
@@ -2371,7 +2372,7 @@
 
 // Computes the sum of the storage used by the various regions.
 size_t G1CollectedHeap::used() const {
-  size_t result = _allocator->used();
+  size_t result = _summary_bytes_used + _allocator->used_in_alloc_regions();
   if (_archive_allocator != NULL) {
     result += _archive_allocator->used();
   }
@@ -2379,7 +2380,7 @@
 }
 
 size_t G1CollectedHeap::used_unlocked() const {
-  return _allocator->used_unlocked();
+  return _summary_bytes_used;
 }
 
 class SumUsedClosure: public HeapRegionClosure {
@@ -4102,7 +4103,7 @@
         _young_list->reset_auxilary_lists();
 
         if (evacuation_failed()) {
-          _allocator->set_used(recalculate_used());
+          set_used(recalculate_used());
           if (_archive_allocator != NULL) {
             _archive_allocator->clear_used();
           }
@@ -4114,7 +4115,7 @@
         } else {
           // The "used" of the the collection set have already been subtracted
           // when they were freed.  Add in the bytes evacuated.
-          _allocator->increase_used(g1_policy()->bytes_copied_during_gc());
+          increase_used(g1_policy()->bytes_copied_during_gc());
         }
 
         if (collector_state()->during_initial_mark_pause()) {
@@ -5745,7 +5746,7 @@
 }
 
 void G1CollectedHeap::decrement_summary_bytes(size_t bytes) {
-  _allocator->decrease_used(bytes);
+  decrease_used(bytes);
 }
 
 class G1ParCleanupCTTask : public AbstractGangTask {
@@ -6395,6 +6396,21 @@
   _hrm.remove_all_free_regions();
 }
 
+void G1CollectedHeap::increase_used(size_t bytes) {
+  _summary_bytes_used += bytes;
+}
+
+void G1CollectedHeap::decrease_used(size_t bytes) {
+  assert(_summary_bytes_used >= bytes,
+         err_msg("invariant: _summary_bytes_used: " SIZE_FORMAT " should be >= bytes: " SIZE_FORMAT,
+                 _summary_bytes_used, bytes));
+  _summary_bytes_used -= bytes;
+}
+
+void G1CollectedHeap::set_used(size_t bytes) {
+  _summary_bytes_used = bytes;
+}
+
 class RebuildRegionSetsClosure : public HeapRegionClosure {
 private:
   bool            _free_list_only;
@@ -6463,15 +6479,15 @@
   heap_region_iterate(&cl);
 
   if (!free_list_only) {
-    _allocator->set_used(cl.total_used());
+    set_used(cl.total_used());
     if (_archive_allocator != NULL) {
       _archive_allocator->clear_used();
     }
   }
-  assert(_allocator->used_unlocked() == recalculate_used(),
-         err_msg("inconsistent _allocator->used_unlocked(), "
+  assert(used_unlocked() == recalculate_used(),
+         err_msg("inconsistent used_unlocked(), "
                  "value: " SIZE_FORMAT " recalculated: " SIZE_FORMAT,
-                 _allocator->used_unlocked(), recalculate_used()));
+                 used_unlocked(), recalculate_used()));
 }
 
 void G1CollectedHeap::set_refine_cte_cl_concurrency(bool concurrent) {
@@ -6511,7 +6527,7 @@
   assert(alloc_region->is_eden(), "all mutator alloc regions should be eden");
 
   g1_policy()->add_region_to_incremental_cset_lhs(alloc_region);
-  _allocator->increase_used(allocated_bytes);
+  increase_used(allocated_bytes);
   _hr_printer.retire(alloc_region);
   // We update the eden sizes here, when the region is retired,
   // instead of when it's allocated, since this is the point that its

--- a/hotspot/src/share/vm/gc/g1/g1CollectedHeap.hpp	Thu Jul 23 08:45:25 2015 +0200
+++ b/hotspot/src/share/vm/gc/g1/g1CollectedHeap.hpp	Thu Jul 23 11:14:24 2015 +0200
@@ -251,6 +251,15 @@
   // Class that handles the different kinds of allocations.
   G1Allocator* _allocator;
 
+  // Outside of GC pauses, the number of bytes used in all regions other
+  // than the current allocation region(s).
+  size_t _summary_bytes_used;
+
+  void increase_used(size_t bytes);
+  void decrease_used(size_t bytes);
+
+  void set_used(size_t bytes);
+
   // Class that handles archive allocation ranges.
   G1ArchiveAllocator* _archive_allocator;
 

--- a/hotspot/src/share/vm/gc/g1/vmStructs_g1.hpp	Thu Jul 23 08:45:25 2015 +0200
+++ b/hotspot/src/share/vm/gc/g1/vmStructs_g1.hpp	Thu Jul 23 11:14:24 2015 +0200
@@ -45,13 +45,11 @@
   nonstatic_field(HeapRegionManager, _regions,          G1HeapRegionTable)    \
   nonstatic_field(HeapRegionManager, _num_committed,    uint)                 \
                                                                               \
-  nonstatic_field(G1Allocator,     _summary_bytes_used, size_t)               \
-                                                                              \
+  nonstatic_field(G1CollectedHeap, _summary_bytes_used, size_t)               \
   nonstatic_field(G1CollectedHeap, _hrm,                HeapRegionManager)    \
   nonstatic_field(G1CollectedHeap, _g1mm,               G1MonitoringSupport*) \
   nonstatic_field(G1CollectedHeap, _old_set,            HeapRegionSetBase)    \
   nonstatic_field(G1CollectedHeap, _humongous_set,      HeapRegionSetBase)    \
-  nonstatic_field(G1CollectedHeap, _allocator,          G1Allocator*)         \
                                                                               \
   nonstatic_field(G1MonitoringSupport, _eden_committed,     size_t)           \
   nonstatic_field(G1MonitoringSupport, _eden_used,          size_t)           \
@@ -78,12 +76,10 @@
   declare_toplevel_type(HeapRegionSetBase)                                    \
   declare_toplevel_type(HeapRegionSetCount)                                   \
   declare_toplevel_type(G1MonitoringSupport)                                  \
-  declare_toplevel_type(G1Allocator)                                          \
                                                                               \
   declare_toplevel_type(G1CollectedHeap*)                                     \
   declare_toplevel_type(HeapRegion*)                                          \
   declare_toplevel_type(G1MonitoringSupport*)                                 \
-  declare_toplevel_type(G1Allocator*)                                         \
 
 
 #endif // SHARE_VM_GC_G1_VMSTRUCTS_G1_HPP