RFR: 8277990: NMT: Remove NMT shutdown capability [v2]

[David Holmes]

On 3/12/2021 4:23 am, Zhengyu Gu wrote:
> On Thu, 2 Dec 2021 16:23:32 GMT, Thomas Stuefe <stuefe at openjdk.org> wrote:
> 
>> Nice cleanup.
>>
>> You missed a few:
>>
>> * test/lib/jdk/test/whitebox/WhiteBox.java, `NMTChangeTrackingLevel`
>> * test/lib/sun/hotspot/WhiteBox.java, same
> 
> Out of curious, why have two versions?

Historical. WB is primarily a hotspot test aid and resided in the 
hotspot testlibrary in the hotspot repo. Overtime we've been moving to a 
common testlibrary for everyone now we are all in one repo. No idea 
where we are with that consolidation process though. I think the person 
driving that may no longer be around, not sure.

>> Will the removal of WB functions cause incompatibilities with older versions of jtreg (can't imagine it does, just wondering)?

If you mean in terms of @require checking that involves WB I believe 
that support class is part of the repo not jtreg.

Cheers,
David
-----

>>
> No idea.
> 
>> Cheers, Thomas
> 
>> src/hotspot/share/services/nmtCommon.hpp line 67:
>>
>>> 65:   NMT_off,
>>> 66:   NMT_summary,
>>> 67:   NMT_detail
>>
>> I'm fine with removing the explicit numbers here, but could you please add
>>
>> STATIC_ASSERT(off > unknown)
>> STATIC_ASSERT(summary > off)
>> STATIC_ASSERT(detail > summary)
>>
>> somewhere? (Maybe in the cpp file, its not such an eyesore there).
> 
> Good idea, fixed.
> 
> -------------
> 
> PR: https://git.openjdk.java.net/jdk/pull/6640
>