RFR: 8365880: Shenandoah: Unify memory usage accounting in ShenandoahFreeSet [v12]

[Kelvin Nilsen]

On Thu, 2 Oct 2025 23:20:50 GMT, William Kemper <wkemper at openjdk.org> wrote:

>> Kelvin Nilsen has updated the pull request incrementally with five additional commits since the last revision:
>> 
>>  - small refactoring
>>  - OO refinements to used_regions_size()
>>  - fix broken assert from previous commit
>>  - OO refinements to free_unaffiliated_regions()
>>  - OO refinements to max_capacity()
>
> src/hotspot/share/gc/shenandoah/shenandoahConcurrentGC.cpp line 1153:
> 
>> 1151: void ShenandoahConcurrentGC::op_final_update_refs() {
>> 1152:   ShenandoahHeap* const heap = ShenandoahHeap::heap();
>> 1153:   bool is_generational = heap->mode()->is_generational();
> 
> Are the changes here necessary? This is a big PR, it would be helpful to minimize unnecessary changes.

I've reverted these changes.  Thanks.

> src/hotspot/share/gc/shenandoah/shenandoahFullGC.cpp line 1145:
> 
>> 1143:   _preserved_marks->reclaim();
>> 1144: 
>> 1145:   // We defer generation resizing actions until after cset regions have been recycled.  We do this even following an
> 
> Stale comment?

Yes.  Removed.

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PR Review Comment: https://git.openjdk.org/jdk/pull/26867#discussion_r2411316966
PR Review Comment: https://git.openjdk.org/jdk/pull/26867#discussion_r2411321130