Jvm asserts with DynamicNumberOfGCThreads and ParallelRefProcEnabled

[Jon Masamitsu]

Thomas,

Thanks for filing the CR.  I assigned it to myself.

Jon

On 02/08/2016 02:29 AM, Thomas Schatzl wrote:
> Hi Goetz,
>
> On Mon, 2016-02-08 at 07:26 +0000, Lindenmaier, Goetz wrote:
>> Hi,
>>   
>> We have ParallelRefProcEnabled enabled. I found that
>> TestDynamicNumberOfGCThreads.java
>> is asserting because of that.
>>   
>> The following command line runs into
>> g1CollectedHeap, process_discovered_references(), assert(rp->num_q()
>> == no_of_gc_workers) :
>> -XX:+ParallelRefProcEnabled -XX:+UseG1GC -Xmx10M
>> -XX:+UseDynamicNumberOfGCThreads -Xlog:gc+task=trace
>> TestDynamicNumberOfGCThreads$GCTest
>>   
>> On my machine, there are 33 queues,  but only 2 processing threads.
>> I think this either should be fixed, or the combination of flags
>> should be avoided by ergonomics.
>>   
>> Also, the test should be extended by that command line, I guess.
>    filed JDK-8149343. Thanks for reporting this issue.
>
> Thanks,
>    Thomas
>