RFR: JDK-8310233: Fix THP detection on Linux [v3]

[Thomas Stuefe]

On Fri, 14 Jul 2023 05:30:50 GMT, David Holmes <dholmes at openjdk.org> wrote:

>> Thomas Stuefe has updated the pull request incrementally with one additional commit since the last revision:
>> 
>>   Feedback johan
>
> src/hotspot/share/utilities/globalDefinitions.hpp line 413:
> 
>> 411: 
>> 412: #define EXACTFMT            SIZE_FORMAT "%s"
>> 413: #define EXACTFMTARGS(s)     byte_size_in_exact_unit(s), exact_unit_for_byte_size(s)
> 
> Not sure this is worthy of inclusion in globalDefinitions. And I struggle to understand the use of "exact" in this context (pre-existing).

I find it very useful tbh, but of course, that is subjective. These macros complement the existing "PROPER_" format variants above. "PROPER" can lie, since it may round to the chosen SI unit. "PROPER" is useful for human-compatible pretty printing. "EXACT" is similar to proper, but will always choose the units such that no information is lost. E.g. 1G+1K will be shown in "KB".

A comment would certainly be useful, maybe for a followup RFE.

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PR Review Comment: https://git.openjdk.org/jdk/pull/14739#discussion_r1263375519