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

[Thomas Stüfe]

Thank you Zhengyu!

On Tue, May 15, 2018 at 2:22 PM, Zhengyu Gu <zgu at redhat.com> wrote:
> Looks good to me.
>
> Thanks,
>
> -Zhengyu
>
>
> On 05/15/2018 08:04 AM, Thomas Stüfe wrote:
>>
>> Hi,
>>
>> I was able to reproduce the original bug by passing
>> -javaoptions:-XX:-UseCompressedOops to the jtreg harness, and I
>> verified that my proposed fix actually works. No firther tests needed.
>>
>> Now I only need a second (Reviewer) review, since Axel is only Committer.
>>
>> ..Thomas
>>
>> On Mon, May 14, 2018 at 3:31 PM, Thomas Stüfe <thomas.stuefe at gmail.com>
>> wrote:
>>>
>>> (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