--- /dev/null	2018-10-18 10:23:58.286752631 +0200
+++ new/test/hotspot/jtreg/gc/g1/TestPeriodicCollection.java	2018-10-18 16:42:50.100802785 +0200
@@ -0,0 +1,145 @@
+/*
+ * Copyright (c) 2018, 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 TestPeriodicCollection
+ * @requires vm.gc.G1
+ * @summary Verify that heap shrinks when the application is idle.
+ * @library /test/lib /
+ * @modules java.base/jdk.internal.misc
+ * @modules java.management/sun.management
+ * @build sun.hotspot.WhiteBox
+ * @run driver ClassFileInstaller sun.hotspot.WhiteBox
+ *                                sun.hotspot.WhiteBox$WhiteBoxPermission
+ * @run main/othervm -XX:+UnlockDiagnosticVMOptions -XX:+WhiteBoxAPI -Xbootclasspath/a:. -Xms32M -Xmx128M -XX:MinHeapFreeRatio=5 -XX:MaxHeapFreeRatio=25 -XX:+UseG1GC -XX:G1PeriodicGCInterval=3000 -XX:+G1PeriodicGCInvokesConcurrent -Xlog:gc,gc+periodic=debug,gc+ergo+heap=debug TestPeriodicCollection
+ * @run main/othervm -XX:+UnlockDiagnosticVMOptions -XX:+WhiteBoxAPI -Xbootclasspath/a:. -Xms32M -Xmx128M -XX:MinHeapFreeRatio=5 -XX:MaxHeapFreeRatio=25 -XX:+UseG1GC -XX:G1PeriodicGCInterval=3000 -XX:-G1PeriodicGCInvokesConcurrent -Xlog:gc,gc+periodic=debug,gc+ergo+heap=debug TestPeriodicCollection
+ */
+
+import com.sun.management.HotSpotDiagnosticMXBean;
+
+import gc.testlibrary.Helpers;
+
+import java.lang.management.ManagementFactory;
+import java.lang.management.MemoryUsage;
+import java.util.ArrayList;
+import java.util.List;
+import java.text.NumberFormat;
+import static jdk.test.lib.Asserts.*;
+
+import sun.hotspot.WhiteBox;
+
+public class TestPeriodicCollection {
+
+    public static final String MIN_FREE_RATIO_FLAG_NAME = "MinHeapFreeRatio";
+    public static final String MAX_FREE_RATIO_FLAG_NAME = "MaxHeapFreeRatio";
+
+    private static final List<List<byte[]>> garbage = new ArrayList();
+
+    private static final long TOTAL_MEMORY = Runtime.getRuntime().totalMemory();
+    private static final long MAX_MEMORY = Runtime.getRuntime().maxMemory();
+    private static final int IDLE_TIME = 10 * 1000;
+
+    private static final int ARR_SIZE = 64 * 1024; // 64k
+    private static final int LISTS_COUNT = 10;
+    private static final int ARR_COUNT = (int) ((TOTAL_MEMORY / ARR_SIZE) / LISTS_COUNT);
+
+    public static void main(String[] args) {
+        if (ARR_COUNT == 0) {
+            System.out.println("Skipped. Heap is too small");
+            return;
+        }
+
+        if (TOTAL_MEMORY + ARR_SIZE * ARR_COUNT > MAX_MEMORY) {
+            System.out.println("Skipped. Initial heap size is too close to max heap size.");
+            return;
+        }
+
+        new TestPeriodicCollection().test();
+    }
+
+    private final void test() {
+        WhiteBox.getWhiteBox().fullGC();
+
+        MemoryUsagePrinter.printMemoryUsage("init");
+
+        allocate();
+        MemoryUsagePrinter.printMemoryUsage("allocated");
+        MemoryUsage muFull = ManagementFactory.getMemoryMXBean().getHeapMemoryUsage();
+
+        garbage.clear();
+        try {
+            Thread.sleep(IDLE_TIME);
+        } catch (InterruptedException ie) {
+            System.err.println("Skipped. Failed to wait for idle collection");
+        }
+        MemoryUsagePrinter.printMemoryUsage("free");
+        MemoryUsage muFree = ManagementFactory.getMemoryMXBean().getHeapMemoryUsage();
+
+        assertLessThan(muFree.getCommitted(), muFull.getCommitted(), String.format(
+                "committed free heap size is not less than committed full heap size, heap hasn't been shrunk?%n"
+                + "%s = %s%n%s = %s",
+                MIN_FREE_RATIO_FLAG_NAME,
+                ManagementFactory.getPlatformMXBean(HotSpotDiagnosticMXBean.class)
+                    .getVMOption(MIN_FREE_RATIO_FLAG_NAME).getValue(),
+                MAX_FREE_RATIO_FLAG_NAME,
+                ManagementFactory.getPlatformMXBean(HotSpotDiagnosticMXBean.class)
+                    .getVMOption(MAX_FREE_RATIO_FLAG_NAME).getValue()
+        ));
+    }
+
+    private void allocate() {
+
+        for (int i = 0; i < LISTS_COUNT; i++) {
+            List<byte[]> stuff = new ArrayList();
+            allocateList(stuff, ARR_COUNT, ARR_SIZE);
+            MemoryUsagePrinter.printMemoryUsage("allocate #" + (i+1));
+            garbage.add(stuff);
+        }
+    }
+
+    private static void allocateList(List garbage, int count, int size) {
+        for (int i = 0; i < count; i++) {
+            garbage.add(new byte[size]);
+        }
+    }
+}
+
+/**
+ * Prints memory usage to standard output
+ */
+class MemoryUsagePrinter {
+
+    public static final NumberFormat NF = Helpers.numberFormatter();
+
+    public static void printMemoryUsage(String label) {
+        MemoryUsage memusage = ManagementFactory.getMemoryMXBean().getHeapMemoryUsage();
+        float freeratio = 1f - (float) memusage.getUsed() / memusage.getCommitted();
+        System.out.format("[%-24s] init: %-7s, used: %-7s, comm: %-7s, freeRatio ~= %.1f%%%n",
+                label,
+                NF.format(memusage.getInit()),
+                NF.format(memusage.getUsed()),
+                NF.format(memusage.getCommitted()),
+                freeratio * 100
+        );
+    }
+}