Mercurial > hg > truffle
view test/compiler/6880034/Test6880034.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 | c18cbe5936b8 |
children |
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/* * Copyright 2009 SAP AG. 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 * @bug 6880034 * @summary SIGBUS during deoptimisation at a safepoint on 64bit-SPARC * * @run main/othervm -Xcomp -Xbatch -XX:CompileCommand=compileonly,Test6880034,deopt_compiledframe_at_safepoint -XX:+PrintCompilation Test6880034 */ // This test provokes a deoptimisation at a safepoint. // // It achieves this by compiling the method 'deopt_compiledframe_at_safepoint' // before its first usage at a point in time when a call to the virtual method // A::doSomething() from within 'deopt_compiledframe_at_safepoint' can be // optimised to a static call because class A has no descendants. // // Later, when deopt_compiledframe_at_safepoint() is running, class B which // extends A and overrides the virtual method "doSomething()", is loaded // asynchronously in another thread. This makes the compiled code of // 'deopt_compiledframe_at_safepoint' invalid and triggers a deoptimisation of // the frame where 'deopt_compiledframe_at_safepoint' is running in a // loop. // // The deoptimisation leads to a SIGBUS on 64-bit server VMs on SPARC and to // an incorrect result on 32-bit server VMs on SPARC due to a regression // introduced by the change: "6420645: Create a vm that uses compressed oops // for up to 32gb heapsizes" // (http://hg.openjdk.java.net/jdk7/jdk7/hotspot/rev/ba764ed4b6f2). Further // investigation showed that change 6420645 is not really the root cause of // this error but only reveals a problem with the float register encodings in // sparc.ad which was hidden until now. // // Notice that for this test to fail in jtreg it is crucial that // deopt_compiledframe_at_safepoint() runs in the main thread. Otherwise a // crash in deopt_compiledframe_at_safepoint() will not be detected as a test // failure by jtreg. // // Author: Volker H. Simonis class A { public int doSomething() { return 0; } } class B extends A { public B() {} // override 'A::doSomething()' public int doSomething() { return 1; } } class G { public static volatile A a = new A(); // Change 'a' to point to a 'B' object public static void setAtoB() { try { a = (A) ClassLoader. getSystemClassLoader(). loadClass("B"). getConstructor(new Class[] {}). newInstance(new Object[] {}); } catch (Exception e) { System.out.println(e); } } } public class Test6880034 { public static volatile boolean is_in_loop = false; public static volatile boolean stop_while_loop = false; public static double deopt_compiledframe_at_safepoint() { // This will be an optimised static call to A::doSomething() until we load "B" int i = G.a.doSomething(); // Need more than 16 'double' locals in this frame double local1 = 1; double local2 = 2; double local3 = 3; double local4 = 4; double local5 = 5; double local6 = 6; double local7 = 7; double local8 = 8; long k = 0; // Once we load "B", this method will be made 'not entrant' and deoptimised // at the safepoint which is at the end of this loop. while (!stop_while_loop) { if (k == 1) local1 += i; if (k == 2) local2 += i; if (k == 3) local3 += i; if (k == 4) local4 += i; if (k == 5) local5 += i; if (k == 6) local6 += i; if (k == 7) local7 += i; if (k == 8) local8 += i; // Tell the world that we're now running wild in the loop if (k++ == 20000) is_in_loop = true; } return local1 + local2 + local3 + local4 + local5 + local6 + local7 + local8 + i; } public static void main(String[] args) { // Just to resolve G before we compile deopt_compiledframe_at_safepoint() G g = new G(); // Asynchronous thread which will eventually invalidate the code for // deopt_compiledframe_at_safepoint() and therefore triggering a // deoptimisation of that method. new Thread() { public void run() { while (!is_in_loop) { // Wait until the loop is running } // Load class 'B' asynchronously.. G.setAtoB(); // ..and stop the loop stop_while_loop = true; } }.start(); // Run the loop in deopt_compiledframe_at_safepoint() double retVal = deopt_compiledframe_at_safepoint(); System.out.println(retVal == 36 ? "OK" : "ERROR : " + retVal); if (retVal != 36) throw new RuntimeException(); } }