Mercurial > hg > truffle
view test/compiler/7177917/Test7177917.java @ 10246:194f52aa2f23
7176479: G1: JVM crashes on T5-8 system with 1.5 TB heap
Summary: Refactor G1's hot card cache and card counts table into their own files. Simplify the card counts table, including removing the encoding of the card index in each entry. The card counts table now has a 1:1 correspondence with the cards spanned by heap. Space for the card counts table is reserved from virtual memory (rather than C heap) during JVM startup and is committed/expanded when the heap is expanded. Changes were also reviewed-by Vitaly Davidovich.
Reviewed-by: tschatzl, jmasa
author | johnc |
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date | Thu, 09 May 2013 11:16:39 -0700 |
parents | d50605d9417e |
children |
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/* * Copyright (c) 2012, 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. * */ /* * Micro-benchmark for Math.pow() and Math.exp() */ import java.util.*; public class Test7177917 { static double d; static Random r = new Random(0); static long m_pow(double[][] values) { double res = 0; long start = System.nanoTime(); for (int i = 0; i < values.length; i++) { res += Math.pow(values[i][0], values[i][1]); } long stop = System.nanoTime(); d = res; return (stop - start) / 1000; } static long m_exp(double[] values) { double res = 0; long start = System.nanoTime(); for (int i = 0; i < values.length; i++) { res += Math.exp(values[i]); } long stop = System.nanoTime(); d = res; return (stop - start) / 1000; } static double[][] pow_values(int nb) { double[][] res = new double[nb][2]; for (int i = 0; i < nb; i++) { double ylogx = (1 + (r.nextDouble() * 2045)) - 1023; // 2045 rather than 2046 as a safety margin double x = Math.abs(Double.longBitsToDouble(r.nextLong())); while (x != x) { x = Math.abs(Double.longBitsToDouble(r.nextLong())); } double logx = Math.log(x) / Math.log(2); double y = ylogx / logx; res[i][0] = x; res[i][1] = y; } return res; } static double[] exp_values(int nb) { double[] res = new double[nb]; for (int i = 0; i < nb; i++) { double ylogx = (1 + (r.nextDouble() * 2045)) - 1023; // 2045 rather than 2046 as a safety margin double x = Math.E; double logx = Math.log(x) / Math.log(2); double y = ylogx / logx; res[i] = y; } return res; } static public void main(String[] args) { { // warmup double[][] warmup_values = pow_values(10); m_pow(warmup_values); for (int i = 0; i < 20000; i++) { m_pow(warmup_values); } // test pow perf double[][] values = pow_values(1000000); System.out.println("==> POW " + m_pow(values)); // force uncommon trap double[][] nan_values = new double[1][2]; nan_values[0][0] = Double.NaN; nan_values[0][1] = Double.NaN; m_pow(nan_values); // force recompilation for (int i = 0; i < 20000; i++) { m_pow(warmup_values); } // test pow perf again System.out.println("==> POW " + m_pow(values)); } { // warmup double[] warmup_values = exp_values(10); m_exp(warmup_values); for (int i = 0; i < 20000; i++) { m_exp(warmup_values); } // test pow perf double[] values = exp_values(1000000); System.out.println("==> EXP " + m_exp(values)); // force uncommon trap double[] nan_values = new double[1]; nan_values[0] = Double.NaN; m_exp(nan_values); // force recompilation for (int i = 0; i < 20000; i++) { m_exp(warmup_values); } // test pow perf again System.out.println("==> EXP " + m_exp(values)); } } }