RFR: 8222252 - Java ergonomics limits heap to 128GB with disabled compressed oops

[Thomas Schatzl]

Hi,

On Wed, 2019-05-15 at 10:52 -0400, Bob Vandette wrote:
> I’ve updated the webrev based on your comments.
> 
> http://cr.openjdk.java.net/~bobv/8222252/webrev.02/
> 
> Changes:
> 
> 1. MaxRAM is updated if fractional flags cause us to use OS memory
> size for heap selection.
> 2. If MaxRAM is specified with the other fractional based flags, we
> will use MaxRAM as
>    upper limit instead of OS memory size.
> 
> 
> Here’s a proposed CSR for this behavioral change.
> 
> https://bugs.openjdk.java.net/browse/JDK-8223957

Please provide a jtreg test checking resulting heap sizing in the
various situations. Not all combinations are interesting of course,
e.g. I think the *Fraction flags can be ignored in these tests as they
are obsolete and others.

The value of os::physical_memory() could be provided by an appropriate
whitebox method if not already done.

Thanks,
  Thomas