RFR: 8366157: Clarify in man pages that only G1 supports MaxGCPauseMillis

[Jonas Norlinder]

On Thu, 28 Aug 2025 07:09:49 GMT, Thomas Schatzl <tschatzl at openjdk.org> wrote:

>> Hi all,
>> 
>> This patch clarifies the description of `MaxGCPauseMillis`.
>
> src/java.base/share/man/java.md line 2507:
> 
>> 2505:     specified value doesn't adapt to your heap size. G1's default for the
>> 2506:     maximum pause time target is 200 milliseconds and only G1 currently supports
>> 2507:     a maximum GC pause time target.
> 
> Suggestion:
> 
>     specified value doesn't adapt to your heap size. The default value is 200 milliseconds.
>     Currently only G1 supports a maximum GC pause time target.
> 
> 
> Reason for this suggestion:
> * it seems more important that only G1 supports this value than the default value, so put this first
> * these are two separate statements, so put them into two separate sentences. The default value is also independent of the collector.

> The specified value doesn't adapt to your heap size.

Should we consider putting this last as that seems like a less important implementation detail compared to which GC support it and the default value?

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PR Review Comment: https://git.openjdk.org/jdk/pull/26940#discussion_r2306587544