RFR: 8332362: Implement os::committed_in_range for MacOS and AIX [v2]

[Martin Doerr]

On Tue, 11 Jun 2024 14:16:26 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.
>
> Robert Toyonaga has updated the pull request incrementally with one additional commit since the last revision:
> 
>   Remove debug log. Enable tests for aix.

This version doesn't build on AIX:

os_posix.cpp:186:36: error: no matching function for call to 'mincore'
    while ((mincore_return_value = mincore(loop_base, pages_to_query * page_sz, vec)) == -1 && errno == EAGAIN);
                                   ^~~~~~~
/usr/include/sys/mman.h:190:14: note: candidate function not viable: no known conversion from 'address' (aka 'unsigned char *') to 'caddr_t' (aka 'char *') for 1st argument
        extern int              mincore(caddr_t, size_t, char *);
                                ^

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PR Comment: https://git.openjdk.org/jdk/pull/19455#issuecomment-2161493068