RFR: Handle old, pinned regions [v7]

[William Kemper]

On Fri, 5 Aug 2022 07:25:52 GMT, Y. Srinivas Ramakrishna <ysr at openjdk.org> wrote:

>> William Kemper has updated the pull request with a new target base due to a merge or a rebase. The pull request now contains 21 commits:
>> 
>>  - Merge branch 'shenandoah-master' into fill-old-pinned
>>  - Do not drop abbreviated argument when recording success concurrent cycle
>>  - Fix whitespace
>>  - Prepare for review
>>  - Merge branch 'shenandoah-master' into fill-old-pinned
>>  - Validate old gen state transitions
>>  - Make use of old generation without down casting
>>  - Make verifier aware of changes to old generation state machine
>>  - Make rset scan aware of changes to old generation state machine
>>  - Fix use of index as count and over-counting of garbage
>>  - ... and 11 more: https://git.openjdk.org/shenandoah/compare/60e43d04...bdda91d6
>
> src/hotspot/share/gc/shenandoah/heuristics/shenandoahOldHeuristics.cpp line 274:
> 
>> 272:                _last_old_collection_candidate,
>> 273:                byte_size_in_proper_unit(collectable_garbage), proper_unit_for_byte_size(collectable_garbage),
>> 274:                byte_size_in_proper_unit(immediate_garbage), proper_unit_for_byte_size(immediate_garbage));
> 
> See earlier comment about potentially underreporting `immediate_garbage`. Also, although `immediate_regions` is tracked, it doesn't seem to ever get used anywhere. May be it used to be reported at some point in the past but is no longer? Eliminate its tracking then?

I will report it in the log. We intend to use this value in the same fashion as young collections.

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

PR: https://git.openjdk.org/shenandoah/pull/149