--- /dev/null	2018-04-03 12:55:20.301839954 +0200
+++ new/src/hotspot/os_cpu/linux_x86/gc/z/zPhysicalMemoryBacking_linux_x86.hpp	2018-06-06 00:41:31.643746104 +0200
@@ -0,0 +1,63 @@
+/*
+ * Copyright (c) 2015, 2017, 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 OS_CPU_LINUX_X86_ZPHYSICALMEMORYBACKING_LINUX_X86_HPP
+#define OS_CPU_LINUX_X86_ZPHYSICALMEMORYBACKING_LINUX_X86_HPP
+
+#include "gc/z/zBackingFile_linux_x86.hpp"
+#include "gc/z/zMemory.hpp"
+
+class ZErrno;
+class ZPhysicalMemory;
+
+class ZPhysicalMemoryBacking {
+private:
+  ZMemoryManager _manager;
+  ZBackingFile   _file;
+  const size_t   _granule_size;
+
+  void check_max_map_count(size_t max_capacity, size_t granule_size) const;
+  void map_failed(ZErrno err) const;
+
+  void advise_view(uintptr_t addr, size_t size) const;
+  void pretouch_view(uintptr_t addr, size_t size) const;
+  void map_view(ZPhysicalMemory pmem, uintptr_t addr, bool pretouch) const;
+  void unmap_view(ZPhysicalMemory pmem, uintptr_t addr) const;
+
+public:
+  ZPhysicalMemoryBacking(size_t max_capacity, size_t granule_size);
+
+  bool is_initialized() const;
+
+  bool expand(size_t from, size_t to);
+  ZPhysicalMemory alloc(size_t size);
+  void free(ZPhysicalMemory pmem);
+
+  uintptr_t nmt_address(uintptr_t offset) const;
+
+  void map(ZPhysicalMemory pmem, uintptr_t offset) const;
+  void unmap(ZPhysicalMemory pmem, uintptr_t offset) const;
+  void flip(ZPhysicalMemory pmem, uintptr_t offset) const;
+};
+
+#endif // OS_CPU_LINUX_X86_ZPHYSICALMEMORYBACKING_LINUX_X86_HPP