RFR: 8204088: Dynamic Max Memory Limit

[Thomas Schatzl]

Hi,

On Wed, 2018-06-20 at 18:32 +0200, Per Liden wrote:
> Hi Rodrigo,
> 
> A general comment, which applies to both JDK-8204088 and JDK-8204089, 
> is that I would like to see this code move into G1 itself. We should
> strive to avoid introducing global concepts and options that are not
> applicable to other GCs. I can't see anything obvious in neither JDK-
> 8204088 nor JDK-8204089 that would stop you from doing that.

  only talking about the option changes for JDK-8204088 right now, but
I think it would be useful that the CurrentMaxHeapSize flag should be
gc global - it is a known useful feature that is also already available
in J9.

It would be a waste of time to first implement it G1 specific (and
potentially using a G1 prefix for it, e.g. G1CurrentMaxHeapSize) and
then it gets picked up by others.

I am mostly concerned about removing and maintaining both
G1CurrentMaxHeapSize and CurrentHeapMaxSize for some time if it can be
avoided (given that other VMs already implemented it, and it does seem
more generally useful than many other "generic" GC options there are).

Thanks,
  Thomas