1 /* 2 * Copyright (c) 2020, 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 package gc.z; 25 26 /* 27 * @test TestPageCacheFlush 28 * @requires vm.gc.Z & !vm.graal.enabled 29 * @summary Test ZGC page cache flushing 30 * @library / /test/lib 31 * @run main/othervm gc.z.TestPageCacheFlush 32 */ 33 34 import java.util.LinkedList; 35 import jdk.test.lib.process.ProcessTools; 36 37 import static gc.testlibrary.Allocation.blackHole; 38 39 public class TestPageCacheFlush { 40 static class Test { 41 private static final int K = 1024; 42 private static final int M = K * K; 43 private static volatile LinkedList<byte[]> keepAlive; 44 45 public static void fillPageCache(int size) { 46 System.out.println("Begin allocate (" + size + ")"); 47 48 keepAlive = new LinkedList<>(); 49 50 try { 51 for (;;) { 52 keepAlive.add(new byte[size]); 53 } 54 } catch (OutOfMemoryError e) { 55 keepAlive = null; 56 System.gc(); 57 } 58 59 System.out.println("End allocate (" + size + ")"); 60 } 61 62 public static void main(String[] args) throws Exception { 63 // Allocate small objects to fill the page cache with small pages 64 fillPageCache(10 * K); 65 66 // Allocate large objects to provoke page cache flushing to rebuild 67 // cached small pages into large pages 68 fillPageCache(10 * M); 69 } 70 } 71 72 public static void main(String[] args) throws Exception { 73 ProcessTools.executeProcess(ProcessTools.createJavaProcessBuilder( 74 "-XX:+UseZGC", 75 "-Xms128M", 76 "-Xmx128M", 77 "-Xlog:gc,gc+init,gc+heap=debug", 78 Test.class.getName())) 79 .outputTo(System.out) 80 .errorTo(System.out) 81 .shouldContain("Page Cache Flushed:") 82 .shouldHaveExitValue(0); 83 } 84 }