--- old/test/TEST.groups	2017-04-05 13:14:44.056738330 +0200
+++ new/test/TEST.groups	2017-04-05 13:14:43.900737556 +0200
@@ -130,7 +130,10 @@
   sanity/ExecuteInternalVMTests.java
 
 hotspot_tier1_gc_gcold = \
-  gc/stress/TestGCOld.java
+  gc/stress/gcold/TestGCOldWithG1.java
+  gc/stress/gcold/TestGCOldWithCMS.java
+  gc/stress/gcold/TestGCOldWithSerial.java
+  gc/stress/gcold/TestGCOldWithParallel.java
 
 hotspot_tier1_gc_gcbasher = \
   gc/stress/gcbasher/TestGCBasherWithG1.java \
--- old/test/gc/stress/TestGCOld.java	2017-04-05 13:14:44.648741266 +0200
+++ /dev/null	2017-03-29 12:42:18.512049647 +0200
@@ -1,419 +0,0 @@
-/*
- * Copyright (c) 2015, 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 TestGCOld
- * @key gc
- * @key stress
- * @requires vm.gc=="null"
- * @summary Stress the GC by trying to make old objects more likely to be garbage than young objects.
- * @run main/othervm -Xmx384M -XX:+UseSerialGC TestGCOld 50 1 20 10 10000
- * @run main/othervm -Xmx384M -XX:+UseParallelGC TestGCOld 50 1 20 10 10000
- * @run main/othervm -Xmx384M -XX:+UseParallelGC -XX:-UseParallelOldGC TestGCOld 50 1 20 10 10000
- * @run main/othervm -Xmx384M -XX:+UseConcMarkSweepGC TestGCOld 50 1 20 10 10000
- * @run main/othervm -Xmx384M -XX:+UseG1GC TestGCOld 50 1 20 10 10000
- * @run main/othervm -Xms64m -Xmx128m -XX:+UseG1GC -XX:+UseDynamicNumberOfGCThreads -Xlog:gc,gc+task=trace TestGCOld 50 5 20 1 5000
- * @run main/othervm -Xms64m -Xmx128m -XX:+UseG1GC -XX:+UseDynamicNumberOfGCThreads  -XX:+UnlockDiagnosticVMOptions -XX:+InjectGCWorkerCreationFailure -Xlog:gc,gc+task=trace TestGCOld 50 5 20 1 5000
- */
-
-import java.text.*;
-import java.util.Random;
-
-class TreeNode {
-    public TreeNode left, right;
-    public int val;                // will always be the height of the tree
-}
-
-
-/* Args:
-   live-data-size: in megabytes (approximate, will be rounded down).
-   work: units of mutator non-allocation work per byte allocated,
-     (in unspecified units.  This will affect the promotion rate
-      printed at the end of the run: more mutator work per step implies
-      fewer steps per second implies fewer bytes promoted per second.)
-   short/long ratio: ratio of short-lived bytes allocated to long-lived
-      bytes allocated.
-   pointer mutation rate: number of pointer mutations per step.
-   steps: number of steps to do.
-*/
-
-public class TestGCOld {
-
-  // Command-line parameters.
-
-  private static int size, workUnits, promoteRate, ptrMutRate, steps;
-
-  // Constants.
-
-  private static final int MEG = 1000000;
-  private static final int INSIGNIFICANT = 999; // this many bytes don't matter
-  private static final int BYTES_PER_WORD = 4;
-  private static final int BYTES_PER_NODE = 20; // bytes per TreeNode
-  private static final int WORDS_DEAD = 100;    // size of young garbage object
-
-  private final static int treeHeight = 14;
-  private final static long treeSize = heightToBytes(treeHeight);
-
-  private static final String msg1
-    = "Usage: java TestGCOld <size> <work> <ratio> <mutation> <steps>";
-  private static final String msg2
-    = "  where <size> is the live storage in megabytes";
-  private static final String msg3
-    = "        <work> is the mutator work per step (arbitrary units)";
-  private static final String msg4
-    = "        <ratio> is the ratio of short-lived to long-lived allocation";
-  private static final String msg5
-    = "        <mutation> is the mutations per step";
-  private static final String msg6
-    = "        <steps> is the number of steps";
-
-  // Counters (and global variables that discourage optimization)
-
-  private static long youngBytes = 0;    // total young bytes allocated
-  private static long nodes = 0;         // total tree nodes allocated
-  private static long actuallyMut = 0;   // pointer mutations in old trees
-  private static long mutatorSum = 0;    // checksum to discourage optimization
-  public static int[] aexport;           // exported array to discourage opt
-
-  // Global variables.
-
-  private static TreeNode[] trees;
-  private static int where = 0;               // roving index into trees
-  private static Random rnd = new Random();
-
-  // Returns the height of the given tree.
-
-  private static int height (TreeNode t) {
-    if (t == null) {
-      return 0;
-    }
-    else {
-      return 1 + Math.max (height (t.left), height (t.right));
-    }
-  }
-
-  // Returns the length of the shortest path in the given tree.
-
-  private static int shortestPath (TreeNode t) {
-    if (t == null) {
-      return 0;
-    }
-    else {
-      return 1 + Math.min (shortestPath (t.left), shortestPath (t.right));
-    }
-  }
-
-  // Returns the number of nodes in a balanced tree of the given height.
-
-  private static long heightToNodes (int h) {
-    if (h == 0) {
-      return 0;
-    }
-    else {
-      long n = 1;
-      while (h > 1) {
-        n = n + n;
-        h = h - 1;
-      }
-      return n + n - 1;
-    }
-  }
-
-  // Returns the number of bytes in a balanced tree of the given height.
-
-  private static long heightToBytes (int h) {
-    return BYTES_PER_NODE * heightToNodes (h);
-  }
-
-  // Returns the height of the largest balanced tree
-  // that has no more than the given number of nodes.
-
-  private static int nodesToHeight (long nodes) {
-    int h = 1;
-    long n = 1;
-    while (n + n - 1 <= nodes) {
-      n = n + n;
-      h = h + 1;
-    }
-    return h - 1;
-  }
-
-  // Returns the height of the largest balanced tree
-  // that occupies no more than the given number of bytes.
-
-  private static int bytesToHeight (long bytes) {
-    return nodesToHeight (bytes / BYTES_PER_NODE);
-  }
-
-  // Returns a newly allocated balanced binary tree of height h.
-
-  private static TreeNode makeTree(int h) {
-    if (h == 0) return null;
-    else {
-      TreeNode res = new TreeNode();
-      nodes++;
-      res.left = makeTree(h-1);
-      res.right = makeTree(h-1);
-      res.val = h;
-      return res;
-    }
-  }
-
-  // Allocates approximately size megabytes of trees and stores
-  // them into a global array.
-
-  private static void init() {
-    int ntrees = (int) ((size * MEG) / treeSize);
-    trees = new TreeNode[ntrees];
-
-    System.err.println("Allocating " + ntrees + " trees.");
-    System.err.println("  (" + (ntrees * treeSize) + " bytes)");
-    for (int i = 0; i < ntrees; i++) {
-      trees[i] = makeTree(treeHeight);
-      // doYoungGenAlloc(promoteRate*ntrees*treeSize, WORDS_DEAD);
-    }
-    System.err.println("  (" + nodes + " nodes)");
-
-    /* Allow any in-progress GC to catch up... */
-    // try { Thread.sleep(20000); } catch (InterruptedException x) {}
-  }
-
-  // Confirms that all trees are balanced and have the correct height.
-
-  private static void checkTrees() {
-    int ntrees = trees.length;
-    for (int i = 0; i < ntrees; i++) {
-      TreeNode t = trees[i];
-      int h1 = height(t);
-      int h2 = shortestPath(t);
-      if ((h1 != treeHeight) || (h2 != treeHeight)) {
-        System.err.println("*****BUG: " + h1 + " " + h2);
-      }
-    }
-  }
-
-  // Called only by replaceTree (below) and by itself.
-
-  private static void replaceTreeWork(TreeNode full, TreeNode partial, boolean dir) {
-    boolean canGoLeft = full.left != null && full.left.val > partial.val;
-    boolean canGoRight = full.right != null && full.right.val > partial.val;
-    if (canGoLeft && canGoRight) {
-      if (dir)
-        replaceTreeWork(full.left, partial, !dir);
-      else
-        replaceTreeWork(full.right, partial, !dir);
-    } else if (!canGoLeft && !canGoRight) {
-      if (dir)
-        full.left = partial;
-      else
-        full.right = partial;
-    } else if (!canGoLeft) {
-      full.left = partial;
-    } else {
-      full.right = partial;
-    }
-  }
-
-  // Given a balanced tree full and a smaller balanced tree partial,
-  // replaces an appropriate subtree of full by partial, taking care
-  // to preserve the shape of the full tree.
-
-  private static void replaceTree(TreeNode full, TreeNode partial) {
-    boolean dir = (partial.val % 2) == 0;
-    actuallyMut++;
-    replaceTreeWork(full, partial, dir);
-  }
-
-  // Allocates approximately n bytes of long-lived storage,
-  // replacing oldest existing long-lived storage.
-
-  private static void oldGenAlloc(long n) {
-    int full = (int) (n / treeSize);
-    long partial = n % treeSize;
-    // System.out.println("In oldGenAlloc, doing " + full + " full trees "
-    // + "and one partial tree of size " + partial);
-    for (int i = 0; i < full; i++) {
-      trees[where++] = makeTree(treeHeight);
-      if (where == trees.length) where = 0;
-    }
-    while (partial > INSIGNIFICANT) {
-      int h = bytesToHeight(partial);
-      TreeNode newTree = makeTree(h);
-      replaceTree(trees[where++], newTree);
-      if (where == trees.length) where = 0;
-      partial = partial - heightToBytes(h);
-    }
-  }
-
-  // Interchanges two randomly selected subtrees (of same size and depth).
-
-  private static void oldGenSwapSubtrees() {
-    // Randomly pick:
-    //   * two tree indices
-    //   * A depth
-    //   * A path to that depth.
-    int index1 = rnd.nextInt(trees.length);
-    int index2 = rnd.nextInt(trees.length);
-    int depth = rnd.nextInt(treeHeight);
-    int path = rnd.nextInt();
-    TreeNode tn1 = trees[index1];
-    TreeNode tn2 = trees[index2];
-    for (int i = 0; i < depth; i++) {
-      if ((path & 1) == 0) {
-        tn1 = tn1.left;
-        tn2 = tn2.left;
-      } else {
-        tn1 = tn1.right;
-        tn2 = tn2.right;
-      }
-      path >>= 1;
-    }
-    TreeNode tmp;
-    if ((path & 1) == 0) {
-      tmp = tn1.left;
-      tn1.left = tn2.left;
-      tn2.left = tmp;
-    } else {
-      tmp = tn1.right;
-      tn1.right = tn2.right;
-      tn2.right = tmp;
-    }
-    actuallyMut += 2;
-  }
-
-  // Update "n" old-generation pointers.
-
-  private static void oldGenMut(long n) {
-    for (int i = 0; i < n/2; i++) {
-      oldGenSwapSubtrees();
-    }
-  }
-
-  // Does the amount of mutator work appropriate for n bytes of young-gen
-  // garbage allocation.
-
-  private static void doMutWork(long n) {
-    int sum = 0;
-    long limit = workUnits*n/10;
-    for (long k = 0; k < limit; k++) sum++;
-    // We don't want dead code elimination to eliminate the loop above.
-    mutatorSum = mutatorSum + sum;
-  }
-
-  // Allocate n bytes of young-gen garbage, in units of "nwords"
-  // words.
-
-  private static void doYoungGenAlloc(long n, int nwords) {
-    final int nbytes = nwords*BYTES_PER_WORD;
-    int allocated = 0;
-    while (allocated < n) {
-      aexport = new int[nwords];
-      /* System.err.println("Step"); */
-      allocated += nbytes;
-    }
-    youngBytes = youngBytes + allocated;
-  }
-
-  // Allocate "n" bytes of young-gen data; and do the
-  // corresponding amount of old-gen allocation and pointer
-  // mutation.
-
-  // oldGenAlloc may perform some mutations, so this code
-  // takes those mutations into account.
-
-  private static void doStep(long n) {
-    long mutations = actuallyMut;
-
-    doYoungGenAlloc(n, WORDS_DEAD);
-    doMutWork(n);
-    oldGenAlloc(n / promoteRate);
-    oldGenMut(Math.max(0L, (mutations + ptrMutRate) - actuallyMut));
-  }
-
-  public static void main(String[] args) {
-    if (args.length != 5) {
-      System.err.println(msg1);
-      System.err.println(msg2);
-      System.err.println(msg3);
-      System.err.println(msg4);
-      System.err.println(msg5);
-      System.err.println(msg6);
-      return;
-    }
-
-    size = Integer.parseInt(args[0]);
-    workUnits = Integer.parseInt(args[1]);
-    promoteRate = Integer.parseInt(args[2]);
-    ptrMutRate = Integer.parseInt(args[3]);
-    steps = Integer.parseInt(args[4]);
-
-    System.out.println(size + " megabytes of live storage");
-    System.out.println(workUnits + " work units per step");
-    System.out.println("promotion ratio is 1:" + promoteRate);
-    System.out.println("pointer mutation rate is " + ptrMutRate);
-    System.out.println(steps + " steps");
-
-    init();
-//  checkTrees();
-    youngBytes = 0;
-    nodes = 0;
-
-    System.err.println("Initialization complete...");
-
-    long start = System.currentTimeMillis();
-
-    for (int step = 0; step < steps; step++) {
-      doStep(MEG);
-    }
-
-    long end = System.currentTimeMillis();
-    float secs = ((float)(end-start))/1000.0F;
-
-//  checkTrees();
-
-    NumberFormat nf = NumberFormat.getInstance();
-    nf.setMaximumFractionDigits(1);
-    System.out.println("\nTook " + nf.format(secs) + " sec in steady state.");
-    nf.setMaximumFractionDigits(2);
-    System.out.println("Allocated " + steps + " Mb of young gen garbage"
-                       + " (= " + nf.format(((float)steps)/secs) +
-                       " Mb/sec)");
-    System.out.println("    (actually allocated " +
-                       nf.format(((float) youngBytes)/MEG) + " megabytes)");
-    float promoted = ((float)steps) / (float)promoteRate;
-    System.out.println("Promoted " + promoted +
-                       " Mb (= " + nf.format(promoted/secs) + " Mb/sec)");
-    System.out.println("    (actually promoted " +
-                       nf.format(((float) (nodes * BYTES_PER_NODE))/MEG) +
-                       " megabytes)");
-    if (ptrMutRate != 0) {
-      System.out.println("Mutated " + actuallyMut +
-                         " pointers (= " +
-                         nf.format(actuallyMut/secs) + " ptrs/sec)");
-
-    }
-    // This output serves mainly to discourage optimization.
-    System.out.println("Checksum = " + (mutatorSum + aexport.length));
-
-  }
-}
--- /dev/null	2017-03-29 12:42:18.512049647 +0200
+++ new/test/gc/stress/gcold/TestGCOld.java	2017-04-05 13:14:44.432740195 +0200
@@ -0,0 +1,404 @@
+/*
+ * Copyright (c) 2015, 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.
+ */
+
+import java.text.*;
+import java.util.Random;
+
+class TreeNode {
+    public TreeNode left, right;
+    public int val;                // will always be the height of the tree
+}
+
+
+/* Args:
+   live-data-size: in megabytes (approximate, will be rounded down).
+   work: units of mutator non-allocation work per byte allocated,
+     (in unspecified units.  This will affect the promotion rate
+      printed at the end of the run: more mutator work per step implies
+      fewer steps per second implies fewer bytes promoted per second.)
+   short/long ratio: ratio of short-lived bytes allocated to long-lived
+      bytes allocated.
+   pointer mutation rate: number of pointer mutations per step.
+   steps: number of steps to do.
+*/
+
+public class TestGCOld {
+
+  // Command-line parameters.
+
+  private static int size, workUnits, promoteRate, ptrMutRate, steps;
+
+  // Constants.
+
+  private static final int MEG = 1000000;
+  private static final int INSIGNIFICANT = 999; // this many bytes don't matter
+  private static final int BYTES_PER_WORD = 4;
+  private static final int BYTES_PER_NODE = 20; // bytes per TreeNode
+  private static final int WORDS_DEAD = 100;    // size of young garbage object
+
+  private final static int treeHeight = 14;
+  private final static long treeSize = heightToBytes(treeHeight);
+
+  private static final String msg1
+    = "Usage: java TestGCOld <size> <work> <ratio> <mutation> <steps>";
+  private static final String msg2
+    = "  where <size> is the live storage in megabytes";
+  private static final String msg3
+    = "        <work> is the mutator work per step (arbitrary units)";
+  private static final String msg4
+    = "        <ratio> is the ratio of short-lived to long-lived allocation";
+  private static final String msg5
+    = "        <mutation> is the mutations per step";
+  private static final String msg6
+    = "        <steps> is the number of steps";
+
+  // Counters (and global variables that discourage optimization)
+
+  private static long youngBytes = 0;    // total young bytes allocated
+  private static long nodes = 0;         // total tree nodes allocated
+  private static long actuallyMut = 0;   // pointer mutations in old trees
+  private static long mutatorSum = 0;    // checksum to discourage optimization
+  public static int[] aexport;           // exported array to discourage opt
+
+  // Global variables.
+
+  private static TreeNode[] trees;
+  private static int where = 0;               // roving index into trees
+  private static Random rnd = new Random();
+
+  // Returns the height of the given tree.
+
+  private static int height (TreeNode t) {
+    if (t == null) {
+      return 0;
+    }
+    else {
+      return 1 + Math.max (height (t.left), height (t.right));
+    }
+  }
+
+  // Returns the length of the shortest path in the given tree.
+
+  private static int shortestPath (TreeNode t) {
+    if (t == null) {
+      return 0;
+    }
+    else {
+      return 1 + Math.min (shortestPath (t.left), shortestPath (t.right));
+    }
+  }
+
+  // Returns the number of nodes in a balanced tree of the given height.
+
+  private static long heightToNodes (int h) {
+    if (h == 0) {
+      return 0;
+    }
+    else {
+      long n = 1;
+      while (h > 1) {
+        n = n + n;
+        h = h - 1;
+      }
+      return n + n - 1;
+    }
+  }
+
+  // Returns the number of bytes in a balanced tree of the given height.
+
+  private static long heightToBytes (int h) {
+    return BYTES_PER_NODE * heightToNodes (h);
+  }
+
+  // Returns the height of the largest balanced tree
+  // that has no more than the given number of nodes.
+
+  private static int nodesToHeight (long nodes) {
+    int h = 1;
+    long n = 1;
+    while (n + n - 1 <= nodes) {
+      n = n + n;
+      h = h + 1;
+    }
+    return h - 1;
+  }
+
+  // Returns the height of the largest balanced tree
+  // that occupies no more than the given number of bytes.
+
+  private static int bytesToHeight (long bytes) {
+    return nodesToHeight (bytes / BYTES_PER_NODE);
+  }
+
+  // Returns a newly allocated balanced binary tree of height h.
+
+  private static TreeNode makeTree(int h) {
+    if (h == 0) return null;
+    else {
+      TreeNode res = new TreeNode();
+      nodes++;
+      res.left = makeTree(h-1);
+      res.right = makeTree(h-1);
+      res.val = h;
+      return res;
+    }
+  }
+
+  // Allocates approximately size megabytes of trees and stores
+  // them into a global array.
+
+  private static void init() {
+    int ntrees = (int) ((size * MEG) / treeSize);
+    trees = new TreeNode[ntrees];
+
+    System.err.println("Allocating " + ntrees + " trees.");
+    System.err.println("  (" + (ntrees * treeSize) + " bytes)");
+    for (int i = 0; i < ntrees; i++) {
+      trees[i] = makeTree(treeHeight);
+      // doYoungGenAlloc(promoteRate*ntrees*treeSize, WORDS_DEAD);
+    }
+    System.err.println("  (" + nodes + " nodes)");
+
+    /* Allow any in-progress GC to catch up... */
+    // try { Thread.sleep(20000); } catch (InterruptedException x) {}
+  }
+
+  // Confirms that all trees are balanced and have the correct height.
+
+  private static void checkTrees() {
+    int ntrees = trees.length;
+    for (int i = 0; i < ntrees; i++) {
+      TreeNode t = trees[i];
+      int h1 = height(t);
+      int h2 = shortestPath(t);
+      if ((h1 != treeHeight) || (h2 != treeHeight)) {
+        System.err.println("*****BUG: " + h1 + " " + h2);
+      }
+    }
+  }
+
+  // Called only by replaceTree (below) and by itself.
+
+  private static void replaceTreeWork(TreeNode full, TreeNode partial, boolean dir) {
+    boolean canGoLeft = full.left != null && full.left.val > partial.val;
+    boolean canGoRight = full.right != null && full.right.val > partial.val;
+    if (canGoLeft && canGoRight) {
+      if (dir)
+        replaceTreeWork(full.left, partial, !dir);
+      else
+        replaceTreeWork(full.right, partial, !dir);
+    } else if (!canGoLeft && !canGoRight) {
+      if (dir)
+        full.left = partial;
+      else
+        full.right = partial;
+    } else if (!canGoLeft) {
+      full.left = partial;
+    } else {
+      full.right = partial;
+    }
+  }
+
+  // Given a balanced tree full and a smaller balanced tree partial,
+  // replaces an appropriate subtree of full by partial, taking care
+  // to preserve the shape of the full tree.
+
+  private static void replaceTree(TreeNode full, TreeNode partial) {
+    boolean dir = (partial.val % 2) == 0;
+    actuallyMut++;
+    replaceTreeWork(full, partial, dir);
+  }
+
+  // Allocates approximately n bytes of long-lived storage,
+  // replacing oldest existing long-lived storage.
+
+  private static void oldGenAlloc(long n) {
+    int full = (int) (n / treeSize);
+    long partial = n % treeSize;
+    // System.out.println("In oldGenAlloc, doing " + full + " full trees "
+    // + "and one partial tree of size " + partial);
+    for (int i = 0; i < full; i++) {
+      trees[where++] = makeTree(treeHeight);
+      if (where == trees.length) where = 0;
+    }
+    while (partial > INSIGNIFICANT) {
+      int h = bytesToHeight(partial);
+      TreeNode newTree = makeTree(h);
+      replaceTree(trees[where++], newTree);
+      if (where == trees.length) where = 0;
+      partial = partial - heightToBytes(h);
+    }
+  }
+
+  // Interchanges two randomly selected subtrees (of same size and depth).
+
+  private static void oldGenSwapSubtrees() {
+    // Randomly pick:
+    //   * two tree indices
+    //   * A depth
+    //   * A path to that depth.
+    int index1 = rnd.nextInt(trees.length);
+    int index2 = rnd.nextInt(trees.length);
+    int depth = rnd.nextInt(treeHeight);
+    int path = rnd.nextInt();
+    TreeNode tn1 = trees[index1];
+    TreeNode tn2 = trees[index2];
+    for (int i = 0; i < depth; i++) {
+      if ((path & 1) == 0) {
+        tn1 = tn1.left;
+        tn2 = tn2.left;
+      } else {
+        tn1 = tn1.right;
+        tn2 = tn2.right;
+      }
+      path >>= 1;
+    }
+    TreeNode tmp;
+    if ((path & 1) == 0) {
+      tmp = tn1.left;
+      tn1.left = tn2.left;
+      tn2.left = tmp;
+    } else {
+      tmp = tn1.right;
+      tn1.right = tn2.right;
+      tn2.right = tmp;
+    }
+    actuallyMut += 2;
+  }
+
+  // Update "n" old-generation pointers.
+
+  private static void oldGenMut(long n) {
+    for (int i = 0; i < n/2; i++) {
+      oldGenSwapSubtrees();
+    }
+  }
+
+  // Does the amount of mutator work appropriate for n bytes of young-gen
+  // garbage allocation.
+
+  private static void doMutWork(long n) {
+    int sum = 0;
+    long limit = workUnits*n/10;
+    for (long k = 0; k < limit; k++) sum++;
+    // We don't want dead code elimination to eliminate the loop above.
+    mutatorSum = mutatorSum + sum;
+  }
+
+  // Allocate n bytes of young-gen garbage, in units of "nwords"
+  // words.
+
+  private static void doYoungGenAlloc(long n, int nwords) {
+    final int nbytes = nwords*BYTES_PER_WORD;
+    int allocated = 0;
+    while (allocated < n) {
+      aexport = new int[nwords];
+      /* System.err.println("Step"); */
+      allocated += nbytes;
+    }
+    youngBytes = youngBytes + allocated;
+  }
+
+  // Allocate "n" bytes of young-gen data; and do the
+  // corresponding amount of old-gen allocation and pointer
+  // mutation.
+
+  // oldGenAlloc may perform some mutations, so this code
+  // takes those mutations into account.
+
+  private static void doStep(long n) {
+    long mutations = actuallyMut;
+
+    doYoungGenAlloc(n, WORDS_DEAD);
+    doMutWork(n);
+    oldGenAlloc(n / promoteRate);
+    oldGenMut(Math.max(0L, (mutations + ptrMutRate) - actuallyMut));
+  }
+
+  public static void main(String[] args) {
+    if (args.length != 5) {
+      System.err.println(msg1);
+      System.err.println(msg2);
+      System.err.println(msg3);
+      System.err.println(msg4);
+      System.err.println(msg5);
+      System.err.println(msg6);
+      return;
+    }
+
+    size = Integer.parseInt(args[0]);
+    workUnits = Integer.parseInt(args[1]);
+    promoteRate = Integer.parseInt(args[2]);
+    ptrMutRate = Integer.parseInt(args[3]);
+    steps = Integer.parseInt(args[4]);
+
+    System.out.println(size + " megabytes of live storage");
+    System.out.println(workUnits + " work units per step");
+    System.out.println("promotion ratio is 1:" + promoteRate);
+    System.out.println("pointer mutation rate is " + ptrMutRate);
+    System.out.println(steps + " steps");
+
+    init();
+//  checkTrees();
+    youngBytes = 0;
+    nodes = 0;
+
+    System.err.println("Initialization complete...");
+
+    long start = System.currentTimeMillis();
+
+    for (int step = 0; step < steps; step++) {
+      doStep(MEG);
+    }
+
+    long end = System.currentTimeMillis();
+    float secs = ((float)(end-start))/1000.0F;
+
+//  checkTrees();
+
+    NumberFormat nf = NumberFormat.getInstance();
+    nf.setMaximumFractionDigits(1);
+    System.out.println("\nTook " + nf.format(secs) + " sec in steady state.");
+    nf.setMaximumFractionDigits(2);
+    System.out.println("Allocated " + steps + " Mb of young gen garbage"
+                       + " (= " + nf.format(((float)steps)/secs) +
+                       " Mb/sec)");
+    System.out.println("    (actually allocated " +
+                       nf.format(((float) youngBytes)/MEG) + " megabytes)");
+    float promoted = ((float)steps) / (float)promoteRate;
+    System.out.println("Promoted " + promoted +
+                       " Mb (= " + nf.format(promoted/secs) + " Mb/sec)");
+    System.out.println("    (actually promoted " +
+                       nf.format(((float) (nodes * BYTES_PER_NODE))/MEG) +
+                       " megabytes)");
+    if (ptrMutRate != 0) {
+      System.out.println("Mutated " + actuallyMut +
+                         " pointers (= " +
+                         nf.format(actuallyMut/secs) + " ptrs/sec)");
+
+    }
+    // This output serves mainly to discourage optimization.
+    System.out.println("Checksum = " + (mutatorSum + aexport.length));
+
+  }
+}
--- /dev/null	2017-03-29 12:42:18.512049647 +0200
+++ new/test/gc/stress/gcold/TestGCOldWithCMS.java	2017-04-05 13:14:45.076743388 +0200
@@ -0,0 +1,36 @@
+/*
+ * Copyright (c) 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 TestGCOldWithCMS
+ * @key gc
+ * @requires vm.gc.ConcMarkSweep
+ * @summary Stress the CMS GC by trying to make old objects more likely to be garbage than young objects.
+ * @run main/othervm -Xmx384M -XX:+UseConcMarkSweepGC TestGCOldWithCMS 50 1 20 10 10000
+ */
+public class TestGCOldWithCMS {
+    public static void main(String[] args) {
+        TestGCOld.main(args);
+    }
+}
--- /dev/null	2017-03-29 12:42:18.512049647 +0200
+++ new/test/gc/stress/gcold/TestGCOldWithG1.java	2017-04-05 13:14:45.640746185 +0200
@@ -0,0 +1,38 @@
+/*
+ * Copyright (c) 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 TestGCOldWithG1
+ * @key gc
+ * @requires vm.gc.G1
+ * @summary Stress the G1 GC by trying to make old objects more likely to be garbage than young objects.
+ * @run main/othervm -Xmx384M -XX:+UseG1GC TestGCOldWithG1 50 1 20 10 10000
+ * @run main/othervm -Xms64m -Xmx128m -XX:+UseG1GC -XX:+UseDynamicNumberOfGCThreads -Xlog:gc,gc+task=trace TestGCOldWithG1 50 5 20 1 5000
+ * @run main/othervm -Xms64m -Xmx128m -XX:+UseG1GC -XX:+UseDynamicNumberOfGCThreads  -XX:+UnlockDiagnosticVMOptions -XX:+InjectGCWorkerCreationFailure -Xlog:gc,gc+task=trace TestGCOldWithG1 50 5 20 1 5000
+ */
+public class TestGCOldWithG1 {
+    public static void main(String[] args) {
+        TestGCOld.main(args);
+    }
+}
--- /dev/null	2017-03-29 12:42:18.512049647 +0200
+++ new/test/gc/stress/gcold/TestGCOldWithParallel.java	2017-04-05 13:14:46.220749061 +0200
@@ -0,0 +1,37 @@
+/*
+ * Copyright (c) 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 TestGCOldWithParallel
+ * @key gc
+ * @requires vm.gc.Parallel
+ * @summary Stress the Parallel GC by trying to make old objects more likely to be garbage than young objects.
+ * @run main/othervm -Xmx384M -XX:+UseParallelGC TestGCOld 50 1 20 10 10000
+ * @run main/othervm -Xmx384M -XX:+UseParallelGC -XX:-UseParallelOldGC TestGCOld 50 1 20 10 10000
+ */
+public class TestGCOldWithParallel {
+    public static void main(String[] args) {
+        TestGCOld.main(args);
+    }
+}
--- /dev/null	2017-03-29 12:42:18.512049647 +0200
+++ new/test/gc/stress/gcold/TestGCOldWithSerial.java	2017-04-05 13:14:46.732751600 +0200
@@ -0,0 +1,36 @@
+/*
+ * Copyright (c) 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 TestGCOldWithSerial
+ * @key gc
+ * @requires vm.gc.Serial
+ * @summary Stress the Serial GC by trying to make old objects more likely to be garbage than young objects.
+ * @run main/othervm -Xmx384M -XX:+UseSerialGC TestGCOldWithSerial 50 1 20 10 10000
+ */
+public class TestGCOldWithSerial {
+    public static void main(String[] args) {
+        TestGCOld.main(args);
+    }
+}