RFC: JEP draft: Automatic Heap Sizing for G1

[Thomas Schatzl]

Hi all,

   with this email I would like to collect feedback for the "Automatic 
Heap Sizing for G1" JEP draft I started writing recently [0].

The purpose of this JEP is to have G1 automatically and dynamically 
adapt the maximum heap size according to the environment.

We think there is fair possibility to complete the implementation by 
next JDK's feature complete date as the main preparatory change [1] is 
currently under review (fwiw, please chime in if interested, more 
feedback is always appreciated).

G1 AHS is somewhat different to ZGC's Automatic Heap Sizing proposal as 
part of the functionality proposed there has already been available in 
G1 for a long time.

It should be fairly complete, although I'm still a bit conflicted about 
the usefulness of the proposed G1GCIntensity flag, but we can always 
change that area as needed.

Thanks,
   Thomas

[0] https://bugs.openjdk.org/browse/JDK-8359211
[1] https://bugs.openjdk.org/browse/JDK-8238687 / 
https://git.openjdk.org/jdk/pull/25832