--- /dev/null	2018-04-03 12:55:20.301839954 +0200
+++ new/src/hotspot/share/gc/z/zPhysicalMemory.cpp	2018-06-08 19:46:32.587258255 +0200
@@ -0,0 +1,179 @@
+/*
+ * 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.
+ */
+
+#include "precompiled.hpp"
+#include "gc/z/zPhysicalMemory.inline.hpp"
+#include "logging/log.hpp"
+#include "memory/allocation.inline.hpp"
+#include "services/memTracker.hpp"
+#include "utilities/debug.hpp"
+
+ZPhysicalMemory::ZPhysicalMemory() :
+    _nsegments(0),
+    _segments(NULL) {}
+
+ZPhysicalMemory::ZPhysicalMemory(size_t size) :
+    _nsegments(0),
+    _segments(NULL) {
+  add_segment(ZPhysicalMemorySegment(0, size));
+}
+
+ZPhysicalMemory::ZPhysicalMemory(const ZPhysicalMemorySegment& segment) :
+    _nsegments(0),
+    _segments(NULL) {
+  add_segment(segment);
+}
+
+size_t ZPhysicalMemory::size() const {
+  size_t size = 0;
+
+  for (size_t i = 0; i < _nsegments; i++) {
+    size += _segments[i].size();
+  }
+
+  return size;
+}
+
+void ZPhysicalMemory::add_segment(ZPhysicalMemorySegment segment) {
+  // Try merge with last segment
+  if (_nsegments > 0) {
+    ZPhysicalMemorySegment& last = _segments[_nsegments - 1];
+    assert(last.end() <= segment.start(), "Segments added out of order");
+    if (last.end() == segment.start()) {
+      // Merge
+      last.expand(segment.size());
+      return;
+    }
+  }
+
+  // Make room for a new segment
+  const size_t size = sizeof(ZPhysicalMemorySegment) * (_nsegments + 1);
+  _segments = (ZPhysicalMemorySegment*)ReallocateHeap((char*)_segments, size, mtGC);
+
+  // Add new segment
+  _segments[_nsegments] = segment;
+  _nsegments++;
+}
+
+ZPhysicalMemory ZPhysicalMemory::split(size_t split_size) {
+  // Only splitting of single-segment instances have been implemented.
+  assert(nsegments() == 1, "Can only have one segment");
+  assert(split_size <= size(), "Invalid size");
+  return ZPhysicalMemory(_segments[0].split(split_size));
+}
+
+void ZPhysicalMemory::clear() {
+  if (_segments != NULL) {
+    FreeHeap(_segments);
+    _segments = NULL;
+    _nsegments = 0;
+  }
+}
+
+ZPhysicalMemoryManager::ZPhysicalMemoryManager(size_t max_capacity, size_t granule_size) :
+    _backing(max_capacity, granule_size),
+    _max_capacity(max_capacity),
+    _capacity(0),
+    _used(0) {}
+
+bool ZPhysicalMemoryManager::is_initialized() const {
+  return _backing.is_initialized();
+}
+
+bool ZPhysicalMemoryManager::ensure_available(size_t size) {
+  const size_t unused_capacity = _capacity - _used;
+  if (unused_capacity >= size) {
+    // Enough unused capacity available
+    return true;
+  }
+
+  const size_t expand_with = size - unused_capacity;
+  const size_t new_capacity = _capacity + expand_with;
+  if (new_capacity > _max_capacity) {
+    // Can not expand beyond max capacity
+    return false;
+  }
+
+  // Expand
+  if (!_backing.expand(_capacity, new_capacity)) {
+    log_error(gc)("Failed to expand Java heap with " SIZE_FORMAT "%s",
+                  byte_size_in_proper_unit(expand_with),
+                  proper_unit_for_byte_size(expand_with));
+    return false;
+  }
+
+  _capacity = new_capacity;
+
+  return true;
+}
+
+void ZPhysicalMemoryManager::nmt_commit(ZPhysicalMemory pmem, uintptr_t offset) {
+  const uintptr_t addr = _backing.nmt_address(offset);
+  const size_t size = pmem.size();
+  MemTracker::record_virtual_memory_commit((void*)addr, size, CALLER_PC);
+}
+
+void ZPhysicalMemoryManager::nmt_uncommit(ZPhysicalMemory pmem, uintptr_t offset) {
+  if (MemTracker::tracking_level() > NMT_minimal) {
+    const uintptr_t addr = _backing.nmt_address(offset);
+    const size_t size = pmem.size();
+
+    Tracker tracker(Tracker::uncommit);
+    tracker.record((address)addr, size);
+  }
+}
+
+ZPhysicalMemory ZPhysicalMemoryManager::alloc(size_t size) {
+  if (!ensure_available(size)) {
+    // Not enough memory available
+    return ZPhysicalMemory();
+  }
+
+  _used += size;
+  return _backing.alloc(size);
+}
+
+void ZPhysicalMemoryManager::free(ZPhysicalMemory pmem) {
+  _backing.free(pmem);
+  _used -= pmem.size();
+}
+
+void ZPhysicalMemoryManager::map(ZPhysicalMemory pmem, uintptr_t offset) {
+  // Map page
+  _backing.map(pmem, offset);
+
+  // Update native memory tracker
+  nmt_commit(pmem, offset);
+}
+
+void ZPhysicalMemoryManager::unmap(ZPhysicalMemory pmem, uintptr_t offset) {
+  // Update native memory tracker
+  nmt_uncommit(pmem, offset);
+
+  // Unmap page
+  _backing.unmap(pmem, offset);
+}
+
+void ZPhysicalMemoryManager::flip(ZPhysicalMemory pmem, uintptr_t offset) {
+  _backing.flip(pmem, offset);
+}