RFR: JDK-8312018: Improve zero-base-optimized reservation of class space [v4]

[Thomas Stuefe]

On Tue, 18 Jul 2023 19:40:39 GMT, Ioi Lam <iklam at openjdk.org> wrote:

>> Thomas Stuefe has updated the pull request with a new target base due to a merge or a rebase. The incremental webrev excludes the unrelated changes brought in by the merge/rebase. The pull request contains five additional commits since the last revision:
>> 
>>  - Feedback David
>>  - Merge branch 'master' into JDK-8312018-Improve-zero-base-optimized-reservation-of-class-space
>>  - Fix Windows
>>  - Feedback Roman; fix off-by-1; fix tracing
>>  - better zero-based reservation strategy
>
> src/hotspot/share/runtime/os.cpp line 1787:
> 
>> 1785: #endif
>> 1786:   - os::vm_page_size());
>> 1787: }
> 
> I am not sure what "attach" means in this sense. If it's the usable address range, wouldn't it need to be OS-specific?

Yes, highest and lowest usable address. You are right in that its OS specific. I'll move these to the respective OS files.

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

PR Review Comment: https://git.openjdk.org/jdk/pull/14867#discussion_r1270248045