RFR: 8229147: Linux os::create_thread() overcounts guardpage size with newer glibc (>=2.27)

[David Holmes]

On Sat, 22 Apr 2023 14:00:07 GMT, Thomas Stuefe <stuefe at openjdk.org> wrote:

>> Can we also assert the lifecycle for this flag is correct? E.g.:
>> 
>> 
>> private:
>>  static bool _init_adjust_...; // Maybe simpler name?
>>  static bool _adjust_...;
>> 
>>  static void init_...() {
>>    ...
>>    _init_adjust_... = true;
>>  }
>> 
>> public:
>>  static bool adjust_stacksize_for_guard_pages() {
>>    assert(_init_adjust..., "Should be initialized");
>>    return _adjust_...;
>>  }
>
> I would it prefer if this switch were named like the behaviour we probe for, not the action that results from it. E.g. "_glibc_includes_guards_in_stack_size". Also makes it clearer that this is a glibc-only thing. And I agree with @shipilev that this looks like a flag. I sometimes prefix local globals with `g_`.
> 
> But its up to you.

<sigh>

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PR Review Comment: https://git.openjdk.org/jdk/pull/13571#discussion_r1174490748