diff -r 4ebc2e2fb97c -r 71c04702a3d5 test/hotspot/jtreg/gc/class_unloading/TestG1ClassUnloadingHWM.java
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/test/hotspot/jtreg/gc/class_unloading/TestG1ClassUnloadingHWM.java	Tue Sep 12 19:03:39 2017 +0200
@@ -0,0 +1,124 @@
+/*
+ * Copyright (c) 2014, 2016, 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.
+ */
+
+/*
+ * @test
+ * @key gc
+ * @bug 8049831
+ * @library /test/lib
+ * @modules java.base/jdk.internal.misc
+ *          java.management
+ * @build sun.hotspot.WhiteBox
+ * @run main ClassFileInstaller sun.hotspot.WhiteBox
+ *                              sun.hotspot.WhiteBox$WhiteBoxPermission
+ * @run driver TestG1ClassUnloadingHWM
+ * @summary Test that -XX:-ClassUnloadingWithConcurrentMark will trigger a Full GC when more than MetaspaceSize metadata is allocated.
+ */
+
+import jdk.test.lib.process.OutputAnalyzer;
+import jdk.test.lib.process.ProcessTools;
+import java.util.ArrayList;
+import java.util.Arrays;
+import sun.hotspot.WhiteBox;
+
+public class TestG1ClassUnloadingHWM {
+  private static long MetaspaceSize = 32 * 1024 * 1024;
+  private static long YoungGenSize  = 32 * 1024 * 1024;
+
+  private static OutputAnalyzer run(boolean enableUnloading) throws Exception {
+    ProcessBuilder pb = ProcessTools.createJavaProcessBuilder(
+      "-Xbootclasspath/a:.",
+      "-XX:+UnlockDiagnosticVMOptions",
+      "-XX:+WhiteBoxAPI",
+      "-XX:MetaspaceSize=" + MetaspaceSize,
+      "-Xmn" + YoungGenSize,
+      "-XX:+UseG1GC",
+      "-XX:" + (enableUnloading ? "+" : "-") + "ClassUnloadingWithConcurrentMark",
+      "-Xlog:gc",
+      TestG1ClassUnloadingHWM.AllocateBeyondMetaspaceSize.class.getName(),
+      "" + MetaspaceSize,
+      "" + YoungGenSize);
+    return new OutputAnalyzer(pb.start());
+  }
+
+  public static OutputAnalyzer runWithG1ClassUnloading() throws Exception {
+    return run(true);
+  }
+
+  public static OutputAnalyzer runWithoutG1ClassUnloading() throws Exception {
+    return run(false);
+  }
+
+  public static void testWithoutG1ClassUnloading() throws Exception {
+    // -XX:-ClassUnloadingWithConcurrentMark is used, so we expect a full GC instead of a concurrent cycle.
+    OutputAnalyzer out = runWithoutG1ClassUnloading();
+
+    out.shouldMatch(".*Pause Full.*");
+    out.shouldNotMatch(".*Pause Initial Mark.*");
+  }
+
+  public static void testWithG1ClassUnloading() throws Exception {
+    // -XX:+ClassUnloadingWithConcurrentMark is used, so we expect a concurrent cycle instead of a full GC.
+    OutputAnalyzer out = runWithG1ClassUnloading();
+
+    out.shouldMatch(".*Pause Initial Mark.*");
+    out.shouldNotMatch(".*Pause Full.*");
+  }
+
+  public static void main(String args[]) throws Exception {
+    testWithG1ClassUnloading();
+    testWithoutG1ClassUnloading();
+  }
+
+  public static class AllocateBeyondMetaspaceSize {
+    public static Object dummy;
+
+    public static void main(String [] args) throws Exception {
+      if (args.length != 2) {
+        throw new IllegalArgumentException("Usage: <MetaspaceSize> <YoungGenSize>");
+      }
+
+      WhiteBox wb = WhiteBox.getWhiteBox();
+
+      // Allocate past the MetaspaceSize limit
+      long metaspaceSize = Long.parseLong(args[0]);
+      long allocationBeyondMetaspaceSize  = metaspaceSize * 2;
+      long metaspace = wb.allocateMetaspace(null, allocationBeyondMetaspaceSize);
+
+      long youngGenSize = Long.parseLong(args[1]);
+      triggerYoungGCs(youngGenSize);
+
+      wb.freeMetaspace(null, metaspace, metaspace);
+    }
+
+    public static void triggerYoungGCs(long youngGenSize) {
+      long approxAllocSize = 32 * 1024;
+      long numAllocations  = 2 * youngGenSize / approxAllocSize;
+
+      for (long i = 0; i < numAllocations; i++) {
+        dummy = new byte[(int)approxAllocSize];
+      }
+    }
+  }
+}
+