RFR: 8337511: Implement JEP-404: Generational Shenandoah (Experimental) [v3]

[Y. Srinivas Ramakrishna]

On Thu, 10 Oct 2024 18:07:27 GMT, Roman Kennke <rkennke 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 478 commits:
>> 
>>  - Fix merge error
>>  - Merge remote-tracking branch 'jdk/master' into great-genshen-pr-redux
>>  - Merge remote-tracking branch 'jdk/master' into great-genshen-pr-redux
>>  - Merge branch 'shenandoah/master' into great-genshen-pr-redux
>>  - Merge
>>  - 8341099: GenShen: assert(HAS_FWD == _heap->has_forwarded_objects()) failed: Forwarded object status is sane
>>    
>>    Reviewed-by: kdnilsen
>>  - 8341485: GenShen: Make evac tracker a non-product feature and confine it to generational mode
>>    
>>    Reviewed-by: kdnilsen, ysr
>>  - Merge
>>  - 8341042: GenShen: Reset mark bitmaps for unaffiliated regions when preparing for a cycle
>>    
>>    Reviewed-by: kdnilsen
>>  - 8339616: GenShen: Introduce new state to distinguish promote-in-place phase as distinct from concurrent evacuation
>>    
>>    Reviewed-by: kdnilsen, shade, ysr
>>  - ... and 468 more: https://git.openjdk.org/jdk/compare/b9db74a6...4db1e0e1
>
> src/hotspot/share/gc/shenandoah/shenandoahCardStats.hpp line 40:
> 
>> 38:   DIRTY_SCAN_OBJS     = 6,
>> 39:   ALTERNATIONS        = 7,
>> 40:   MAX_CARD_STAT_TYPE  = 8
> 
> Are the numerical values relevant or what is the reason to spell them out?

Not needed; explicit enumeration values can be removed.

> src/hotspot/share/gc/shenandoah/shenandoahCardStats.hpp line 46:
> 
>> 44:   CARD_STAT_SCAN_RS       = 0,
>> 45:   CARD_STAT_UPDATE_REFS   = 1,
>> 46:   MAX_CARD_STAT_LOG_TYPE  = 2
> 
> Same here?

Yes, same; explicit enumeration values can be removed.

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

PR Review Comment: https://git.openjdk.org/jdk/pull/21273#discussion_r1797462093
PR Review Comment: https://git.openjdk.org/jdk/pull/21273#discussion_r1797462886