--- a/hotspot/src/share/vm/gc_implementation/g1/concurrentMark.hpp	Mon Apr 04 13:18:35 2011 -0400
+++ b/hotspot/src/share/vm/gc_implementation/g1/concurrentMark.hpp	Mon Apr 04 14:23:17 2011 -0400
@@ -1149,4 +1149,54 @@
 #endif // _MARKING_STATS_
 };
 
+// Class that's used to to print out per-region liveness
+// information. It's currently used at the end of marking and also
+// after we sort the old regions at the end of the cleanup operation.
+class G1PrintRegionLivenessInfoClosure: public HeapRegionClosure {
+private:
+  outputStream* _out;
+
+  // Accumulators for these values.
+  size_t _total_used_bytes;
+  size_t _total_capacity_bytes;
+  size_t _total_prev_live_bytes;
+  size_t _total_next_live_bytes;
+
+  // These are set up when we come across a "stars humongous" region
+  // (as this is where most of this information is stored, not in the
+  // subsequent "continues humongous" regions). After that, for every
+  // region in a given humongous region series we deduce the right
+  // values for it by simply subtracting the appropriate amount from
+  // these fields. All these values should reach 0 after we've visited
+  // the last region in the series.
+  size_t _hum_used_bytes;
+  size_t _hum_capacity_bytes;
+  size_t _hum_prev_live_bytes;
+  size_t _hum_next_live_bytes;
+
+  static double perc(size_t val, size_t total) {
+    if (total == 0) {
+      return 0.0;
+    } else {
+      return 100.0 * ((double) val / (double) total);
+    }
+  }
+
+  static double bytes_to_mb(size_t val) {
+    return (double) val / (double) M;
+  }
+
+  // See the .cpp file.
+  size_t get_hum_bytes(size_t* hum_bytes);
+  void get_hum_bytes(size_t* used_bytes, size_t* capacity_bytes,
+                     size_t* prev_live_bytes, size_t* next_live_bytes);
+
+public:
+  // The header and footer are printed in the constructor and
+  // destructor respectively.
+  G1PrintRegionLivenessInfoClosure(outputStream* out, const char* phase_name);
+  virtual bool doHeapRegion(HeapRegion* r);
+  ~G1PrintRegionLivenessInfoClosure();
+};
+
 #endif // SHARE_VM_GC_IMPLEMENTATION_G1_CONCURRENTMARK_HPP