RFR: 8337217: Port VirtualMemoryTracker to use VMATree [v33]

[Afshin Zafari]

On Thu, 27 Feb 2025 13:29:01 GMT, Johan Sjölen <jsjolen at openjdk.org> wrote:

>> 2 questions:
>> 
>> 1st, I must be misunderstanding something here. Johan asked to change the API from:
>> 
>> `visit_committed_regions(ReservedMemoryRegion& committed_rgn)`
>> 
>> to
>> 
>> `visit_committed_regions(position start, size size)`
>> 
>> but I still see the old way.
>> 
>> 2nd, why are we asking for this change?
>
> We want to remove `ReservedMemoryRegion` in a follow up PR to this one. Another step is to remove the `CommittedMemoryRegion` class as well.

To be more specific, `ReservedMemoryRegion` structure/class will still remain in the code, but the `find_reserved_region(address, size_t)` will be removed. At least, in neither of my PRs it would be removed.
These structs are useful in encapsulating the info about the regions and have been used many times in the code.
Do we have any reason to remove them? 
Anyway, it is better to remove them in the related PRs, if there will be any.

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

PR Review Comment: https://git.openjdk.org/jdk/pull/20425#discussion_r1977368095