--- a/hotspot/src/share/vm/gc_implementation/concurrentMarkSweep/concurrentMarkSweepGeneration.cpp	Mon Apr 22 20:27:36 2013 +0200
+++ b/hotspot/src/share/vm/gc_implementation/concurrentMarkSweep/concurrentMarkSweepGeneration.cpp	Mon Apr 22 22:00:03 2013 -0700
@@ -3426,8 +3426,9 @@
 void ConcurrentMarkSweepGeneration::shrink_free_list_by(size_t bytes) {
   assert_locked_or_safepoint(Heap_lock);
   assert_lock_strong(freelistLock());
-  // XXX Fix when compaction is implemented.
-  warning("Shrinking of CMS not yet implemented");
+  if (PrintGCDetails && Verbose) {
+    warning("Shrinking of CMS not yet implemented");
+  }
   return;
 }
 

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/hotspot/test/gc/concurrentMarkSweep/GuardShrinkWarning.java	Mon Apr 22 22:00:03 2013 -0700
@@ -0,0 +1,60 @@
+/*
+ * Copyright (c) 2013, 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 GuardShrinkWarning
+ * @summary Remove warning about CMS generation shrinking.
+ * @bug 8012111
+ * @key gc
+ * @key regression
+ * @library /testlibrary
+ * @run main/othervm GuardShrinkWarning
+ * @author jon.masamitsu@oracle.com
+ */
+
+import com.oracle.java.testlibrary.*;
+
+public class GuardShrinkWarning {
+  public static void main(String args[]) throws Exception {
+
+    ProcessBuilder pb = ProcessTools.createJavaProcessBuilder(
+      "-showversion",
+      "-XX:+UseConcMarkSweepGC",
+      "-XX:+ExplicitGCInvokesConcurrent",
+      "GuardShrinkWarning$SystemGCCaller"
+      );
+
+    OutputAnalyzer output = new OutputAnalyzer(pb.start());
+
+    output.shouldNotContain("Shrinking of CMS not yet implemented");
+
+    output.shouldNotContain("error");
+
+    output.shouldHaveExitValue(0);
+  }
+  static class SystemGCCaller {
+    public static void main(String [] args) {
+      System.gc();
+    }
+  }
+}