--- /dev/null	2018-04-03 12:55:20.301839954 +0200
+++ new/src/hotspot/os_cpu/linux_x86/gc/z/zBackingFile_linux_x86.hpp	2018-06-08 19:45:44.311163733 +0200
@@ -0,0 +1,58 @@
+/*
+ * 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_ZBACKINGFILE_LINUX_X86_HPP
+#define OS_CPU_LINUX_X86_ZBACKINGFILE_LINUX_X86_HPP
+
+#include "memory/allocation.hpp"
+
+class ZBackingFile {
+private:
+  int      _fd;
+  uint64_t _filesystem;
+  bool     _initialized;
+
+  int create_mem_fd(const char* name) const;
+  int create_file_fd(const char* name) const;
+  int create_fd(const char* name) const;
+
+  bool is_tmpfs() const;
+  bool is_hugetlbfs() const;
+  bool tmpfs_supports_transparent_huge_pages() const;
+
+  bool try_split_and_expand_tmpfs(size_t offset, size_t length, size_t alignment) const;
+  bool try_expand_tmpfs(size_t offset, size_t length, size_t alignment) const;
+  bool expand_tmpfs(size_t offset, size_t length) const;
+
+  bool expand_hugetlbfs(size_t offset, size_t length) const;
+
+public:
+  ZBackingFile();
+
+  bool is_initialized() const;
+
+  int fd() const;
+  bool expand(size_t offset, size_t length) const;
+};
+
+#endif // OS_CPU_LINUX_X86_ZBACKINGFILE_LINUX_X86_HPP