--- a/agent/src/share/classes/sun/jvm/hotspot/gc_implementation/g1/G1CollectedHeap.java	Mon Jan 16 22:10:05 2012 +0100
+++ b/agent/src/share/classes/sun/jvm/hotspot/gc_implementation/g1/G1CollectedHeap.java	Wed Jan 18 10:30:12 2012 -0500
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2011, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2011, 2012, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -49,8 +49,12 @@
     static private long g1CommittedFieldOffset;
     // size_t _summary_bytes_used;
     static private CIntegerField summaryBytesUsedField;
-    // G1MonitoringSupport* _g1mm
+    // G1MonitoringSupport* _g1mm;
     static private AddressField g1mmField;
+    // MasterOldRegionSet _old_set;
+    static private long oldSetFieldOffset;
+    // MasterHumongousRegionSet _humongous_set;
+    static private long humongousSetFieldOffset;
 
     static {
         VM.registerVMInitializedObserver(new Observer() {
@@ -67,12 +71,14 @@
         g1CommittedFieldOffset = type.getField("_g1_committed").getOffset();
         summaryBytesUsedField = type.getCIntegerField("_summary_bytes_used");
         g1mmField = type.getAddressField("_g1mm");
+        oldSetFieldOffset = type.getField("_old_set").getOffset();
+        humongousSetFieldOffset = type.getField("_humongous_set").getOffset();
     }
 
     public long capacity() {
         Address g1CommittedAddr = addr.addOffsetTo(g1CommittedFieldOffset);
-        MemRegion g1_committed = new MemRegion(g1CommittedAddr);
-        return g1_committed.byteSize();
+        MemRegion g1Committed = new MemRegion(g1CommittedAddr);
+        return g1Committed.byteSize();
     }
 
     public long used() {
@@ -94,6 +100,18 @@
         return (G1MonitoringSupport) VMObjectFactory.newObject(G1MonitoringSupport.class, g1mmAddr);
     }
 
+    public HeapRegionSetBase oldSet() {
+        Address oldSetAddr = addr.addOffsetTo(oldSetFieldOffset);
+        return (HeapRegionSetBase) VMObjectFactory.newObject(HeapRegionSetBase.class,
+                                                             oldSetAddr);
+    }
+
+    public HeapRegionSetBase humongousSet() {
+        Address humongousSetAddr = addr.addOffsetTo(humongousSetFieldOffset);
+        return (HeapRegionSetBase) VMObjectFactory.newObject(HeapRegionSetBase.class,
+                                                             humongousSetAddr);
+    }
+
     private Iterator<HeapRegion> heapRegionIterator() {
         return hrs().heapRegionIterator();
     }

--- a/agent/src/share/classes/sun/jvm/hotspot/gc_implementation/g1/G1MonitoringSupport.java	Mon Jan 16 22:10:05 2012 +0100
+++ b/agent/src/share/classes/sun/jvm/hotspot/gc_implementation/g1/G1MonitoringSupport.java	Wed Jan 18 10:30:12 2012 -0500
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2011, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2011, 2012, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -77,6 +77,10 @@
         return edenUsedField.getValue(addr);
     }
 
+    public long edenRegionNum() {
+        return edenUsed() / HeapRegion.grainBytes();
+    }
+
     public long survivorCommitted() {
         return survivorCommittedField.getValue(addr);
     }
@@ -85,6 +89,10 @@
         return survivorUsedField.getValue(addr);
     }
 
+    public long survivorRegionNum() {
+        return survivorUsed() / HeapRegion.grainBytes();
+    }
+
     public long oldCommitted() {
         return oldCommittedField.getValue(addr);
     }

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/agent/src/share/classes/sun/jvm/hotspot/gc_implementation/g1/HeapRegionSetBase.java	Wed Jan 18 10:30:12 2012 -0500
@@ -0,0 +1,81 @@
+/*
+ * Copyright (c) 2012, Oracle and/or its affiliates. All rights reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ *
+ */
+
+package sun.jvm.hotspot.gc_implementation.g1;
+
+import java.util.Iterator;
+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.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;
+
+// Mirror class for HeapRegionSetBase. Represents a group of regions.
+
+public class HeapRegionSetBase extends VMObject {
+    // size_t _length;
+    static private CIntegerField lengthField;
+    // size_t _region_num;
+    static private CIntegerField regionNumField;
+    // size_t _total_used_bytes;
+    static private CIntegerField totalUsedBytesField;
+
+    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("HeapRegionSetBase");
+
+        lengthField         = type.getCIntegerField("_length");
+        regionNumField      = type.getCIntegerField("_region_num");
+        totalUsedBytesField = type.getCIntegerField("_total_used_bytes");
+    }
+
+    public long length() {
+        return lengthField.getValue(addr);
+    }
+
+    public long regionNum() {
+        return regionNumField.getValue(addr);
+    }
+
+    public long totalUsedBytes() {
+        return totalUsedBytesField.getValue(addr);
+    }
+
+    public HeapRegionSetBase(Address addr) {
+        super(addr);
+    }
+}

--- a/agent/src/share/classes/sun/jvm/hotspot/tools/HeapSummary.java	Mon Jan 16 22:10:05 2012 +0100
+++ b/agent/src/share/classes/sun/jvm/hotspot/tools/HeapSummary.java	Wed Jan 18 10:30:12 2012 -0500
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2003, 2011, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2003, 2012, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -67,6 +67,7 @@
       printValue("SurvivorRatio    = ", getFlagValue("SurvivorRatio", flagMap));
       printValMB("PermSize         = ", getFlagValue("PermSize", flagMap));
       printValMB("MaxPermSize      = ", getFlagValue("MaxPermSize", flagMap));
+      printValMB("G1HeapRegionSize = ", HeapRegion.grainBytes());
 
       System.out.println();
       System.out.println("Heap Usage:");
@@ -100,11 +101,20 @@
          } else if (sharedHeap instanceof G1CollectedHeap) {
              G1CollectedHeap g1h = (G1CollectedHeap) sharedHeap;
              G1MonitoringSupport g1mm = g1h.g1mm();
-             System.out.println("G1 Young Generation");
-             printG1Space("Eden Space:", g1mm.edenUsed(), g1mm.edenCommitted());
-             printG1Space("From Space:", g1mm.survivorUsed(), g1mm.survivorCommitted());
-             printG1Space("To Space:", 0, 0);
-             printG1Space("G1 Old Generation", g1mm.oldUsed(), g1mm.oldCommitted());
+             long edenRegionNum = g1mm.edenRegionNum();
+             long survivorRegionNum = g1mm.survivorRegionNum();
+             HeapRegionSetBase oldSet = g1h.oldSet();
+             HeapRegionSetBase humongousSet = g1h.humongousSet();
+             long oldRegionNum = oldSet.regionNum() + humongousSet.regionNum();
+             printG1Space("G1 Heap:", g1h.n_regions(),
+                          g1h.used(), g1h.capacity());
+             System.out.println("G1 Young Generation:");
+             printG1Space("Eden Space:", edenRegionNum,
+                          g1mm.edenUsed(), g1mm.edenCommitted());
+             printG1Space("Survivor Space:", survivorRegionNum,
+                          g1mm.survivorUsed(), g1mm.survivorCommitted());
+             printG1Space("G1 Old Generation:", oldRegionNum,
+                          g1mm.oldUsed(), g1mm.oldCommitted());
          } else {
              throw new RuntimeException("unknown SharedHeap type : " + heap.getClass());
          }
@@ -216,9 +226,11 @@
       System.out.println(alignment +  (double)space.used() * 100.0 / space.capacity() + "% used");
    }
 
-   private void printG1Space(String spaceName, long used, long capacity) {
+   private void printG1Space(String spaceName, long regionNum,
+                             long used, long capacity) {
       long free = capacity - used;
       System.out.println(spaceName);
+      printValue("regions  = ", regionNum);
       printValMB("capacity = ", capacity);
       printValMB("used     = ", used);
       printValMB("free     = ", free);

--- a/src/share/vm/gc_implementation/g1/concurrentMark.cpp	Mon Jan 16 22:10:05 2012 +0100
+++ b/src/share/vm/gc_implementation/g1/concurrentMark.cpp	Wed Jan 18 10:30:12 2012 -0500
@@ -1886,6 +1886,10 @@
   // races with it goes around and waits for completeCleanup to finish.
   g1h->increment_total_collections();
 
+  // We reclaimed old regions so we should calculate the sizes to make
+  // sure we update the old gen/space data.
+  g1h->g1mm()->update_sizes();
+
   if (VerifyDuringGC) {
     HandleMark hm;  // handle scope
     gclog_or_tty->print(" VerifyDuringGC:(after)");

--- a/src/share/vm/gc_implementation/g1/heapRegionSet.hpp	Mon Jan 16 22:10:05 2012 +0100
+++ b/src/share/vm/gc_implementation/g1/heapRegionSet.hpp	Wed Jan 18 10:30:12 2012 -0500
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2011, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2011, 2012, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -59,6 +59,7 @@
 class HeapRegionSetBase VALUE_OBJ_CLASS_SPEC {
   friend class hrs_ext_msg;
   friend class HRSPhaseSetter;
+  friend class VMStructs;
 
 protected:
   static size_t calculate_region_num(HeapRegion* hr);

--- a/src/share/vm/gc_implementation/g1/vmStructs_g1.hpp	Mon Jan 16 22:10:05 2012 +0100
+++ b/src/share/vm/gc_implementation/g1/vmStructs_g1.hpp	Wed Jan 18 10:30:12 2012 -0500
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2011, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2011, 2012, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -40,6 +40,8 @@
   nonstatic_field(G1CollectedHeap, _g1_committed,       MemRegion)            \
   nonstatic_field(G1CollectedHeap, _summary_bytes_used, size_t)               \
   nonstatic_field(G1CollectedHeap, _g1mm,               G1MonitoringSupport*) \
+  nonstatic_field(G1CollectedHeap, _old_set,            HeapRegionSetBase)    \
+  nonstatic_field(G1CollectedHeap, _humongous_set,      HeapRegionSetBase)    \
                                                                               \
   nonstatic_field(G1MonitoringSupport, _eden_committed,     size_t)           \
   nonstatic_field(G1MonitoringSupport, _eden_used,          size_t)           \
@@ -47,6 +49,10 @@
   nonstatic_field(G1MonitoringSupport, _survivor_used,      size_t)           \
   nonstatic_field(G1MonitoringSupport, _old_committed,      size_t)           \
   nonstatic_field(G1MonitoringSupport, _old_used,           size_t)           \
+                                                                              \
+  nonstatic_field(HeapRegionSetBase,   _length,             size_t)           \
+  nonstatic_field(HeapRegionSetBase,   _region_num,         size_t)           \
+  nonstatic_field(HeapRegionSetBase,   _total_used_bytes,   size_t)           \
 
 
 #define VM_TYPES_G1(declare_type, declare_toplevel_type)                      \
@@ -55,6 +61,7 @@
                                                                               \
   declare_type(HeapRegion, ContiguousSpace)                                   \
   declare_toplevel_type(HeapRegionSeq)                                        \
+  declare_toplevel_type(HeapRegionSetBase)                                    \
   declare_toplevel_type(G1MonitoringSupport)                                  \
                                                                               \
   declare_toplevel_type(G1CollectedHeap*)                                     \