RFR: 8332362: Implement os::committed_in_range for MacOS and AIX

[Robert Toyonaga]

On Wed, 29 May 2024 14:04:37 GMT, Robert Toyonaga <duke at openjdk.org> wrote:

> ### Summary
> This change adds `os::committed_in_range` to `src/hotspot/os/posix/os_posix.cpp` so that AIX and MacOS can use it. It is mostly the same as the prior implementation in `os_linux.cpp`, but takes into account AIX may have unaligned stacks and variable page sizes, and that mincore uses a different argument type on linux.  This will allow AIX and MacOS to report true liveness information for thread stacks reported by NMT. Previously this was only possible on Windows and Linux.
> 
> **Testing**
> - `TestAlwaysPreTouchStacks.java` is updated to also test the case when stacks are large but mostly not paged in. 
> - A few new unit tests in `test_committed_virtualmemory.cpp` to check`os::committed_in_range`. I've excluded these tests on Windows because it reports the committed region as fully paged in. 
> - tier1
> 
> I've tested on Linux and Windows. I don't have a Mac to test on, but the Mac GHA tests are passing. Not yet tested on AIX.

Thank you for the feedback!  I applied your suggestions. 
> Then please assert that boundaries are page-aligned. They should be. On AIX, we inner-page-align since [JDK-8332237](https://bugs.openjdk.org/browse/JDK-8332237). 

ok I see, that makes sense. 

My request for machine access is pending, so I still need to confirm nothing breaks on AIX. I'll keep this as a draft for now.

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PR Comment: https://git.openjdk.org/jdk/pull/19455#issuecomment-2145257381