RFR: 8311843: GenShen: assertion failed "Old generation affiliated regions must be less than capacity" [v2]

[Kelvin Nilsen]

On Fri, 25 Aug 2023 23:59:03 GMT, Kelvin Nilsen <kdnilsen at openjdk.org> wrote:

>> I understand that it checks, but the check should never fail, because the two asserts that precede the call (and did not need to be removed) confirm that the region to be flipped is in the Mutator free set (i.e. is part of young capacity) and is entirely empty (so must be unaffiliated).
>> 
>> I need to study the reserve_regions problem more.  I saw that you refactored a bit.  I didn't catch that you were fixing a bug.
>
> Agree that changing shFreeSet to sole arbiter is probably a separate PR, that might be a good improvement.

Given that full-gc is allowed to violate the min/max constraints on generation sizes, I'm inclined to allow the same here, and revert this to force_transfer_to_old().  If that doesn't work, maybe a comment to explain why.  Because I'm not understanding this entirely.

-------------

PR Review Comment: https://git.openjdk.org/shenandoah/pull/311#discussion_r1306239408