[crac] RFR: 8364554: [CRaC] Improve CRaC VM options' docs [v2]

[Radim Vansa]

On Sat, 2 Aug 2025 13:03:59 GMT, Timofei Pushkin <tpushkin at openjdk.org> wrote:

>> Timofei Pushkin has updated the pull request incrementally with one additional commit since the last revision:
>> 
>>   Improve wording for CRaCMinPid
>
> src/java.base/share/man/java.md line 1090:
> 
>> 1088: `-XX:CRaCMinPid=`*value*
>> 1089: :   A desired minimal PID value for checkpointed process. Used by the launcher,
>> 1090:     only on POSIX-like platforms.
> 
> BTW, I thought about removing `CRaCMinPid` from `globals.hpp` since it is not used by the VM at all but decided against it (too big of a change for a pretty general PR like this) and just documented that it is to be used by the launcher.
> 
> Since it is (or should be) possible to use JVM without the default launcher we could add a check in VM that the option is honored and at least warn if it is not.
> 
> Internally we've had similar problems with Tomcat launching JVM directly and thus not honoring options implemented purely in the launcher.

I don't think we should remove; it should be normally listed with `-XX:PrintFlagsFinal` etc.

Regarding wording, I don't think that "launcher" is a term that we should use in user-facing documentation.

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

PR Review Comment: https://git.openjdk.org/crac/pull/256#discussion_r2251565150