Mercurial > hg > graal-compiler
view test/compiler/6880034/Test6880034.java @ 2149:7e37af9d69ef
7011379: G1: overly long concurrent marking cycles
Summary: This changeset introduces filtering of SATB buffers at the point when they are about to be enqueued. If this filtering clears enough entries on each buffer, the buffer can then be re-used and not enqueued. This cuts down the number of SATB buffers that need to be processed by the concurrent marking threads.
Reviewed-by: johnc, ysr
author | tonyp |
---|---|
date | Wed, 19 Jan 2011 09:35:17 -0500 |
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(); } }