RFR: 8366363: MemBaseline accesses VMT without using lock [v14]

[Casper Norrbin]

On Thu, 4 Sep 2025 11:46:26 GMT, Johan Sjölen <jsjolen at openjdk.org> wrote:

>> Hi,
>> 
>> The `MemBaseline` used to access the VMT instance directly without a lock. We fix that, and we switch from using a `LinkedList` to a copied `RegionsTree` instead.
>
> Johan Sjölen has updated the pull request incrementally with one additional commit since the last revision:
> 
>   Missed const-ness

Looks good!

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Marked as reviewed by cnorrbin (Committer).

PR Review: https://git.openjdk.org/jdk/pull/27003#pullrequestreview-3185157530