--- /dev/null	2018-04-03 12:55:20.301839954 +0200
+++ new/src/hotspot/share/gc/z/zPageCache.hpp	2018-06-01 22:30:56.118550307 +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 SHARE_GC_Z_ZPAGECACHE_HPP
+#define SHARE_GC_Z_ZPAGECACHE_HPP
+
+#include "gc/z/zList.hpp"
+#include "gc/z/zPage.hpp"
+#include "gc/z/zValue.hpp"
+#include "memory/allocation.hpp"
+
+class ZPageCache {
+private:
+  size_t                  _available;
+
+  ZPerNUMA<ZList<ZPage> > _small;
+  ZList<ZPage>            _medium;
+  ZList<ZPage>            _large;
+
+  ZPage* alloc_small_page();
+  ZPage* alloc_medium_page();
+  ZPage* alloc_large_page(size_t size);
+
+  void flush_list(ZList<ZPage>* from, size_t requested, ZList<ZPage>* to, size_t* flushed);
+  void flush_per_numa_lists(ZPerNUMA<ZList<ZPage> >* from, size_t requested, ZList<ZPage>* to, size_t* flushed);
+
+public:
+  ZPageCache();
+
+  size_t available() const;
+
+  ZPage* alloc_page(uint8_t type, size_t size);
+  void free_page(ZPage* page);
+
+  void flush(ZList<ZPage>* to, size_t requested);
+};
+
+#endif // SHARE_GC_Z_ZPAGECACHE_HPP