RFR: 8047998: -XX:MaxNewSize is unnecessarily set to NewSize if NewSize is too low

[Guoxiong Li]

On Mon, 29 May 2023 11:43:08 GMT, Albert Mingkun Yang <ayang at openjdk.org> wrote:

> > The condition MaxHeapSize == InitialHeapSize is often meet
> 
> True, but additionally specifying both `NewSize` and `MaxNewSize` is uncommon, IMO.
> 
> > I do worry that such exiting may break some current online systems
> 
> Actually, I think it's desirable to fail loudly if the JVM cmd flags contain errors. Hard to say whether this is an error or not, but debugging suboptimal performance (from incorrect heap/generation-size) is much harder. Therefore, notifying developers at jvm-startup when cmd flags can't be satisfied might be appreciated. Again, this setup should be rare.
> 
> (I agree this is subjective.)

I will be ok with your previous suggestion (exiting the vm) if this PR is intergrated into JDK22, which means we should integrate it into mainline after June 08, 2023 [1] . What do you think about it?

[1] https://openjdk.org/projects/jdk/21/

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PR Comment: https://git.openjdk.org/jdk/pull/13876#issuecomment-1567237493