RFR: 8259962: Shenandoah: task queue statistics is inconsistent after JDK-8255019

[Aleksey Shipilev]

On Tue, 19 Jan 2021 13:11:11 GMT, Zhengyu Gu <zgu at openjdk.org> wrote:

>> I believe `ShenandoahSTWMark` misses the TQ stats reset after the takeover from concurrent cycle. See the stack trace and events info in the bug.
>> 
>> Additional testing:
>>  - [x] Linux x86_64, failing tests now pass
>>  - [x] Linux x86_64 `hotspot_gc_shenandoah`
>>  - [x]  Linux x86_64 `tier1` with Shenandoah
>
> Thanks for catching this. Looks good.
> 
> Concurrent mark resets qstats in ShenandoahConcurrentMark::mark_stw_roots(), so it should be fine.

Thanks!

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

PR: https://git.openjdk.java.net/jdk/pull/2141