RFR: 8263476: NMT: Stack guard pages should not be marked as committed [v2]

[Albert Mingkun Yang]

On Mon, 4 Aug 2025 13:52:41 GMT, Johan Sjölen <jsjolen at openjdk.org> wrote:

>> Albert Mingkun Yang 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 three additional commits since the last revision:
>> 
>>  - review
>>  - Merge branch 'master' into no-commit-stack-guard-page
>>  - no-commit-stack-guard-page
>
> src/hotspot/os/bsd/os_bsd.inline.hpp line 44:
> 
>> 42:   assert(uses_stack_guard_pages(), "sanity check");
>> 43:   return false;
>> 44: }
> 
> I'm missing why it's OK to remove this.

Previously, we require stack-guard-pages to be committed, and mmap MAP_STACK does "lazy" commit, so we have to perform commit explicitly. Now, we switch to reserve-only stack-guard-pages, so no explicit commit is needed.

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PR Review Comment: https://git.openjdk.org/jdk/pull/26571#discussion_r2251679047