RFR: Add generations to freeset [v5]

[Kelvin Nilsen]

On Thu, 13 Apr 2023 11:21:09 GMT, Aleksey Shipilev <shade at openjdk.org> wrote:

>> Kelvin Nilsen has updated the pull request incrementally with one additional commit since the last revision:
>> 
>>   Remove debug instrumentation
>
> src/hotspot/share/gc/shenandoah/shenandoahFreeSet.cpp line 652:
> 
>> 650: }
>> 651: 
>> 652: bool ShenandoahFreeSet::expand_collector_bounds_maybe(size_t idx) {
> 
> For this and the following method, the return value is not used, can be dropped.

done

> src/hotspot/share/gc/shenandoah/shenandoahFreeSet.cpp line 1065:
> 
>> 1063:         buffer[idx] = 'C';
>> 1064:       }
>> 1065:       else if (r->is_humongous()) {
> 
> Suggestion:
> 
>       } else if (r->is_humongous()) {

fixed.

> src/hotspot/share/gc/shenandoah/shenandoahHeap.hpp line 323:
> 
>> 321: 
>> 322:     // The evacuation reserves for old-gen and young-gen are available
>> 323:     VALID_EVACUATION_RESERVE_QUANTITIES_BITPOS = 6
> 
> I think we only do these when we want to access the flags from generated code. If we only do the accesses from the GC code, this could be just a plan `bool` field.

Thanks for explanation.  I'm changing to use a boolean.

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

PR Review Comment: https://git.openjdk.org/shenandoah/pull/250#discussion_r1170588359
PR Review Comment: https://git.openjdk.org/shenandoah/pull/250#discussion_r1170589727
PR Review Comment: https://git.openjdk.org/shenandoah/pull/250#discussion_r1170590252