RFR: 8351091: Shenandoah: global marking context completeness is not accurately maintained [v7]

[Xiaolong Peng]

On Thu, 3 Apr 2025 21:39:33 GMT, Y. Srinivas Ramakrishna <ysr at openjdk.org> wrote:

>> Xiaolong Peng has updated the pull request incrementally with one additional commit since the last revision:
>> 
>>   Can't verify marked object with complete marking after full GC
>
> src/hotspot/share/gc/shenandoah/shenandoahVerifier.cpp line 1191:
> 
>> 1189:           _verify_remembered_after_full_gc,  // verify read-write remembered set
>> 1190:           _verify_forwarded_none,      // all objects are non-forwarded
>> 1191:           _verify_marked_incomplete,   // all objects are marked in incomplete bitmap
> 
> Is the marking bitmap updated as objects are moved to their new locations? Is that done just to satisfy the verifier?

Yes, making bitmaps has been reset after full GC,  except for the for regions with pined objects.
_verify_marked_complete requires complete marking context, it might make more sense to change it to _verify_marked_disable after full GC.

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PR Review Comment: https://git.openjdk.org/jdk/pull/23886#discussion_r2027835236