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

Yumin Qi minqi at openjdk.java.net
Thu Oct 15 03:01:09 UTC 2020


On Thu, 15 Oct 2020 02:52:18 GMT, Yumin Qi <minqi at openjdk.org> wrote:

>> Unfortunately, the following fix doesn't work.
>> Platform.isDebugBuild() ? "-XX:-VerifyDependencies" : "",
>> It seems that ProcessTools.createJavaProcessBuilder doesn't allow empty string as an arg.
>> 
>> Would you mind something like:
>> Platform.isDebugBuild() ? "-XX:-VerifyDependencies" : "-XX:MaxMetaspaceSize=16m",
>> If you don't like it, I still prefer -XX:+IgnoreUnrecognizedVMOptions.
>> I've grepped under jdk/test finding that there are about 700+ tests using -XX:+IgnoreUnrecognizedVMOptions.
>> I didn't get the point why -XX:+IgnoreUnrecognizedVMOptions should be avoided for this case.
>
> 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.

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

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


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