RFR: 8252921: NMT overwrite memory type for region assert when building dynamic archive [v6]

[David Holmes]

On Mon, 21 Sep 2020 14:19:44 GMT, Zhengyu Gu <zgu at openjdk.org> wrote:

>> Thread stack is currently unregistered with NMT in Thread's destructor. Apparently, only Java thread invokes destructor
>> before thread exits.  For NonJavaThread, e.g. ConcurrentGCThread, thread may exit while its "Thread" object continues
>> alive, therefore, its thread stack is still "alive" from NMT perspective. Once thread exits, the virtual memory for the
>> thread stack can be reserved again, that confused NMT.  The solution is to move thread stack unregistration code to
>> post_run() method.
>
> Zhengyu Gu has updated the pull request incrementally with two additional commits since the last revision:
> 
>  - Fix indents
>  - Back out thread stack cleaning, to be addressed by JDK-8253429

Thanks for restoring those bits. Dealing with the way non-JavaThreads terminate is a known issue (there may already be
an open JBS issue for that) and that is best dealt with directly in that context rather than as part of this change.
Thanks.

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Marked as reviewed by dholmes (Reviewer).

PR: https://git.openjdk.java.net/jdk/pull/185