Intentional heap bounds change?

[Roman Kennke]

Hello GC devs,

I see a case where heap may shrink below -Xms. This may be intentional 
or not. -Xms is initial heap size after all, not necessarily minimum 
heap size. However, there is also documentation that -Xms *does* provide 
the lower bounds for heap sizing policy, e.g. [1]

I believe this is due to this change:

https://github.com/openjdk/jdk/commit/1ed5b22d6e48ffbebaa53cf79df1c5c790aa9d71#diff-74a766b0aa16c688981a4d7b20da1c93315ce72358cac7158e9b50f82c9773a3L567

I.e. instead of adjusting old-gen minimum size with young-gen minimum 
size, it is set to _gen_alignment.

Is this intentional?

Thanks,
Roman


[1] 
https://docs.oracle.com/en/java/javase/11/gctuning/factors-affecting-garbage-collection-performance.html#GUID-B0BFEFCB-F045-4105-BFA4-C97DE81DAC5B