--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/hotspot/share/gc/parallel/heterogeneousGenerationSizer.hpp	Fri Dec 21 08:23:55 2018 -0800
@@ -0,0 +1,46 @@
+/*
+ * Copyright (c) 2018, 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.
+ *
+ */
+
+#ifndef SHARE_VM_GC_PARALLEL_HETEROGENEOUSGENERATIONSIZER_HPP
+#define SHARE_VM_GC_PARALLEL_HETEROGENEOUSGENERATIONSIZER_HPP
+
+#include "gc/parallel/generationSizer.hpp"
+
+// There is a nice batch of tested generation sizing code in
+// GenCollectorPolicy. Lets reuse it!
+
+class HeterogeneousGenerationSizer : public GenerationSizer {
+private:
+  // Max fraction of dram to use for young generation when MaxRAMFraction and
+  // MaxRAMPercentage are not specified on commandline.
+  static const double MaxRamFractionForYoung;
+
+protected:
+  virtual void initialize_flags();
+
+public:
+  virtual size_t heap_reserved_size_bytes() const;
+  virtual bool is_hetero_heap() const;
+};
+#endif // SHARE_VM_GC_PARALLEL_HETEROGENEOUSGENERATIONSIZER_HPP