1 /*
   2  * Copyright (c) 2012, 2015, Oracle and/or its affiliates. All rights reserved.
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.
   8  *
   9  * This code is distributed in the hope that it will be useful, but WITHOUT
  10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  12  * version 2 for more details (a copy is included in the LICENSE file that
  13  * accompanied this code).
  14  *
  15  * You should have received a copy of the GNU General Public License version
  16  * 2 along with this work; if not, write to the Free Software Foundation,
  17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  18  *
  19  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  20  * or visit www.oracle.com if you need additional information or have any
  21  * questions.
  22  */
  23 
  24 /*
  25  * @test TestHumongousAllocInitialMark
  26  * @bug 7168848
  27  * @summary G1: humongous object allocations should initiate marking cycles when necessary
  28  * @library /testlibrary
  29  * @modules java.base/sun.misc
  30  *          java.management
  31  */
  32 
  33 import jdk.test.lib.*;
  34 
  35 public class TestHumongousAllocInitialMark {
  36     // Heap sizes < 224 MB are increased to 224 MB if vm_page_size == 64K to
  37     // fulfill alignment constraints.
  38     private static final int heapSize                       = 224; // MB
  39     private static final int heapRegionSize                 = 1;   // MB
  40     private static final int initiatingHeapOccupancyPercent = 50;  // %
  41 
  42     public static void main(String[] args) throws Exception {
  43         ProcessBuilder pb = ProcessTools.createJavaProcessBuilder(
  44             "-XX:+UseG1GC",
  45             "-Xms" + heapSize + "m",
  46             "-Xmx" + heapSize + "m",
  47             "-XX:G1HeapRegionSize=" + heapRegionSize + "m",
  48             "-XX:InitiatingHeapOccupancyPercent=" + initiatingHeapOccupancyPercent,
  49             "-XX:+PrintGC",
  50             HumongousObjectAllocator.class.getName());
  51 
  52         OutputAnalyzer output = new OutputAnalyzer(pb.start());
  53         output.shouldContain("GC pause (G1 Humongous Allocation) (young) (initial-mark)");
  54         output.shouldNotContain("Full GC");
  55         output.shouldHaveExitValue(0);
  56     }
  57 
  58     static class HumongousObjectAllocator {
  59         private static byte[] dummy;
  60 
  61         public static void main(String [] args) throws Exception {
  62             // Make object size 75% of region size
  63             final int humongousObjectSize =
  64                 (int)(heapRegionSize * 1024 * 1024 * 0.75);
  65 
  66             // Number of objects to allocate to go above IHOP
  67             final int humongousObjectAllocations =
  68                 (int)((heapSize * initiatingHeapOccupancyPercent / 100.0) / heapRegionSize) + 1;
  69 
  70             // Allocate
  71             for (int i = 1; i <= humongousObjectAllocations; i++) {
  72                 System.out.println("Allocating humongous object " + i + "/" + humongousObjectAllocations +
  73                                    " of size " + humongousObjectSize + " bytes");
  74                 dummy = new byte[humongousObjectSize];
  75             }
  76         }
  77     }
  78 }
  79