--- /dev/null	2020-09-04 12:37:41.765504620 +0200
+++ new/src/hotspot/share/memory/metaspace/msCommitMask.cpp	2020-09-04 13:57:48.837340821 +0200
@@ -0,0 +1,77 @@
+/*
+ * Copyright (c) 2020, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2020 SAP SE. 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 "memory/metaspace/msCommitMask.hpp"
+#include "memory/metaspace/msCommon.hpp"
+#include "memory/metaspace/msSettings.hpp"
+#include "runtime/stubRoutines.hpp"
+
+#include "utilities/align.hpp"
+#include "utilities/debug.hpp"
+
+namespace metaspace {
+
+CommitMask::CommitMask(const MetaWord* start, size_t word_size)
+  : CHeapBitMap(mask_size(word_size, Settings::commit_granule_words()))
+  , _base(start)
+  , _word_size(word_size)
+  , _words_per_bit(Settings::commit_granule_words())
+{
+  assert(_word_size > 0 && _words_per_bit > 0 &&
+         is_aligned(_word_size, _words_per_bit), "Sanity");
+}
+
+#ifdef ASSERT
+
+void CommitMask::verify() const {
+
+  // Walk the whole commit mask.
+  // For each 1 bit, check if the associated granule is accessible.
+  // For each 0 bit, check if the associated granule is not accessible. Slow mode only.
+
+  assert(_base != NULL && _word_size > 0 && _words_per_bit > 0, "Sanity");
+  assert_is_aligned(_base, _words_per_bit * BytesPerWord);
+  assert_is_aligned(_word_size, _words_per_bit);
+
+}
+
+#endif // ASSERT
+
+void CommitMask::print_on(outputStream* st) const {
+
+  st->print("commit mask, base " PTR_FORMAT ":", p2i(base()));
+
+  for (idx_t i = 0; i < size(); i++) {
+    st->print("%c", at(i) ? 'X' : '-');
+  }
+
+  st->cr();
+
+}
+
+} // namespace metaspace
+