RFR(xxs): 8203032: PrintMetaspaceDcmd fails: 'Non-Class:' missing from stdout/stderr

[Thomas Stüfe]

(webrev: http://cr.openjdk.java.net/~stuefe/webrevs/8203032-PrintMetaspaceDCmd-fails/webrev.00/webrev/)

Thanks, Thomas

On Mon, May 14, 2018 at 11:52 AM, Thomas Stüfe <thomas.stuefe at gmail.com> wrote:
> Hi all,
>
> may I please have reviews for this small fix:
>
> Bug: https://bugs.openjdk.java.net/browse/JDK-8203032
>
> Fix:
>
> diff -r 2f79462aab9b
> test/hotspot/jtreg/runtime/Metaspace/PrintMetaspaceDcmd.java
> --- a/test/hotspot/jtreg/runtime/Metaspace/PrintMetaspaceDcmd.java
>  Mon May 07 09:11:21 2018 +0200
> +++ b/test/hotspot/jtreg/runtime/Metaspace/PrintMetaspaceDcmd.java
>  Mon May 14 11:46:23 2018 +0200
> @@ -33,8 +33,8 @@
>   * @library /test/lib
>   * @modules java.base/jdk.internal.misc
>   *          java.management
> - * @run main/othervm -XX:MaxMetaspaceSize=201M -XX:+VerifyMetaspace
> -XX:+UseCompressedClassPointers PrintMetaspaceDcmd
> with-compressed-class-space
> - * @run main/othervm -XX:MaxMetaspaceSize=201M -XX:+VerifyMetaspace
> -XX:-UseCompressedClassPointers PrintMetaspaceDcmd
> without-compressed-class-space
> + * @run main/othervm -XX:MaxMetaspaceSize=201M -Xmx100M
> -XX:+UseCompressedOops -XX:+UseCompressedClassPointers
> PrintMetaspaceDcmd with-compressed-class-space
> + * @run main/othervm -XX:MaxMetaspaceSize=201M -Xmx100M
> -XX:-UseCompressedOops -XX:-UseCompressedClassPointers
> PrintMetaspaceDcmd without-compressed-class-space
>   */
>
>
> There had been two issues:
>
> 1) I let the test run with -XX:+VerifyMetaspace, but that one is a
> debug only option, so the test fails in release build. Well, that was
> just stupid :)
>
> My fix is to just remove the option, since I do not know how to
> specify an option for debug VMs only.
>
> 2) The test requires the VM to be started with
> +UseCompressedClassPointers, and assumed +UseCompressedOops would be
> always set, because it is default. However, the test is started with
> CompressedOops explicitly turned off. I do not understand why but my
> assumtion is that it has to do with -XX:MaxRAMPercentage=8 and running
> on a big machine, where 8% of the available RAM would bring the VM
> above the max. 32G heapsize needed to have compressed oops.
>
> My fix is to first, specify -XX:+UseCompressedOops explicitly, and
> second to limit the max heap size to -Xmx100M. I hope this will
> overrule the -XX:MaxRAMPercentage=8 handed down from above? But since
> I do not know exactly via which way this option came down, I cannot
> reproduce and test. So, I would be obliged if someone could test if
> this fix fixes the issues on Oracles tests.
>
>
> Thanks, Thomas