--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/main/java/org/openjdk/gcbench/wip/BarriersSlowpath.java	Wed Jun 20 11:04:33 2018 +0200
@@ -0,0 +1,97 @@
+/*
+ * Copyright (c) 2017, Red Hat Inc. 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.  Oracle designates this
+ * particular file as subject to the "Classpath" exception as provided
+ * by Oracle in the LICENSE file that accompanied this code.
+ *
+ * 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.
+ */
+package org.openjdk.gcbench.wip;
+
+import org.openjdk.jmh.annotations.*;
+
+import java.util.ArrayList;
+import java.util.List;
+import java.util.concurrent.TimeUnit;
+
+@Warmup(iterations = 5, time = 1, timeUnit = TimeUnit.SECONDS)
+@Measurement(iterations = 5, time = 1, timeUnit = TimeUnit.SECONDS)
+@Fork(1)
+@BenchmarkMode(Mode.AverageTime)
+@OutputTimeUnit(TimeUnit.NANOSECONDS)
+@Threads(Threads.MAX)
+@State(Scope.Benchmark)
+public class BarriersSlowpath {
+
+    Object retain;
+
+    @Param({"100000"})
+    private int size;
+
+    @Setup
+    public void setup() {
+        List<Node> nodes = new ArrayList<>();
+        for (int c = 0; c < size; c++) {
+            nodes.add(new Node(null, null));
+        }
+
+        while (nodes.size() > 1) {
+            List<Node> newNodes = new ArrayList<>();
+            for (int c = 0; c < nodes.size(); c += 2) {
+                if (c + 1 < nodes.size()) {
+                    newNodes.add(new Node(nodes.get(c), nodes.get(c + 1)));
+                } else {
+                    // non-balanced tree
+                    newNodes.add(new Node(nodes.get(c), null));
+                }
+            }
+            nodes = newNodes;
+        }
+
+        retain = nodes.get(0);
+
+        System.gc();
+    }
+
+    Object src = new Object();
+
+    @State(Scope.Thread)
+    public static class Holder {
+        Object dst = new Object();
+    }
+
+    @Benchmark
+    @CompilerControl(CompilerControl.Mode.DONT_INLINE)
+    public void test(Holder h) {
+        // make SATB great again
+        h.dst = src;
+    }
+
+    private static class Node {
+        final Node left;
+        final Node right;
+        final Object payload;
+        public Node(Node left, Node right) {
+            this.left = left;
+            this.right = right;
+            this.payload = new Object();
+        }
+    }
+
+}