RFR: 8366363: MemBaseline accesses VMT without using lock

[Johan Sjölen]

On Fri, 29 Aug 2025 12:13:57 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.

src/hotspot/share/utilities/rbTree.hpp line 454:

> 452: public:
> 453:   RBTree() : BaseType(), _allocator() {}
> 454:   RBTree(const RBTree& other) : BaseType(), _allocator() {

@caspernorrbin , I added this. Does it look correct?

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

PR Review Comment: https://git.openjdk.org/jdk/pull/27003#discussion_r2310890005