RFR: 8254799: runtime/ErrorHandling/TestHeapDumpOnOutOfMemoryError.java fails with release VMs

[Jie Fu]

On Thu, 15 Oct 2020 02:58:46 GMT, Yumin Qi <minqi at openjdk.org> wrote:

>> Hi, Jie, David and Dan, I would like to reorg the code a little bit:
>> 
>> `index a889ae11ed1..596ca348c30 100644
>> --- a/test/hotspot/jtreg/runtime/ErrorHandling/TestHeapDumpOnOutOfMemoryError.java
>> +++ b/test/hotspot/jtreg/runtime/ErrorHandling/TestHeapDumpOnOutOfMemoryError.java
>> @@ -31,10 +31,12 @@
>>  import jdk.test.lib.Asserts;
>>  import jdk.test.lib.classloader.GeneratingClassLoader;
>>  import jdk.test.lib.hprof.HprofParser;
>> +import jdk.test.lib.Platform;
>>  import jdk.test.lib.process.ProcessTools;
>>  import jdk.test.lib.process.OutputAnalyzer;
>> 
>>  import java.io.File;
>> +import java.util.ArrayList;
>> 
>>  public class TestHeapDumpOnOutOfMemoryError {
>> 
>> @@ -64,22 +66,29 @@ public class TestHeapDumpOnOutOfMemoryError {
>>      }
>> 
>>      static void test(String type) throws Exception {
>> +        ArrayList<String> args = new ArrayList();
>> +
>>          String heapdumpFilename = type + ".hprof";
>> -        ProcessBuilder pb = ProcessTools.createJavaProcessBuilder("-XX:+HeapDumpOnOutOfMemoryError",
>> -                "-XX:HeapDumpPath=" + heapdumpFilename,
>> -                // Note: When trying to provoke a metaspace OOM we may generate a lot of classes. In debug VMs this
>> -                //  can cause considerable wait times since:
>> -                // - Compiler Dependencies verification iterates the class tree
>> -                // - Before exit, the CLDG is checked.
>> -                // Both verifications show quadratic time or worse wrt to number of loaded classes. Therefore it
>> -                //  makes sense to switch one or both off and limit the metaspace size to something sensible.
>> -                // Example numbers on a slow ppc64 machine:
>> -                //  MaxMetaspaceSize=64M - ~60-70K classes - ~20min runtime with all verifications
>> -                //  MaxMetaspaceSize=16M - ~12-15K classes - ~12sec runtime with all verifications
>> -                //  MaxMetaspaceSize=16M - ~12-15K classes - VerifyDependencies off - ~3seconds on ppc
>> -                "-XX:MaxMetaspaceSize=16m",
>> -                "-XX:-VerifyDependencies",
>> -                TestHeapDumpOnOutOfMemoryError.class.getName(), type);
>> +        // Note: When trying to provoke a metaspace OOM we may generate a lot of classes. In debug VMs this
>> +        //  can cause considerable wait times since:
>> +        // - Compiler Dependencies verification iterates the class tree
>> +        // - Before exit, the CLDG is checked.
>> +        // Both verifications show quadratic time or worse wrt to number of loaded classes. Therefore it
>> +        //  makes sense to switch one or both off and limit the metaspace size to something sensible.
>> +        // Example numbers on a slow ppc64 machine:
>> +        //  MaxMetaspaceSize=64M - ~60-70K classes - ~20min runtime with all verifications
>> +        //  MaxMetaspaceSize=16M - ~12-15K classes - ~12sec runtime with all verifications
>> +        //  MaxMetaspaceSize=16M - ~12-15K classes - VerifyDependencies off - ~3seconds on ppc
>> +        args.add("-XX:+HeapDumpOnOutOfMemoryError");
>> +        args.add("-XX:HeapDumpPath=" + heapdumpFilename);
>> +        args.add("-XX:MaxMetaspaceSize=16m");
>> +        if (Platform.isDebugBuild()) {
>> +            args.add("-XX:-VerifyDependencies");
>> +        }
>> +        args.add(TestHeapDumpOnOutOfMemoryError.class.getName());
>> +        args.add(type);
>> +
>> +        ProcessBuilder pb = ProcessTools.createJavaProcessBuilder(args);
>> 
>>          OutputAnalyzer output = new OutputAnalyzer(pb.start());
>>          output.stdoutShouldNotBeEmpty();`
>> 
>> 
>> 
>> What do you think?
>
> Aha, the diff looks ugly.  Basically ProcessTools.createJavaProcessBuilder(List<?>) so you can manage the code there.

Hi @yminqi
To fix this bug, I prefer David's suggestion, which seems simple and elegant.
Thanks.

-------------

PR: https://git.openjdk.java.net/jdk/pull/673