RFR: 8373116: Genshen: arraycopy_work should be always done for arrays in old gen during young concurrent marking [v7]

[William Kemper]

On Mon, 8 Dec 2025 21:43:26 GMT, Xiaolong Peng <xpeng at openjdk.org> wrote:

>> Thanks to make it so clear, I did similar evaluation and knew we will call arraycopy_work when (B && C) is true, but it shouldn't cause crash from OldGC, we will be more conservative in such case resulting in maybe more live objects.
>> 
>> I'll try to make the tests here more accurate in the PR.
>
> arraycopy_work will be called when (B && C) is true if only A is also true, it is expected and what we wanted.

Condition `D` should be sufficient when we are marking old. That is, I don't believe we need to check `B` or `C` when we are marking old.

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PR Review Comment: https://git.openjdk.org/jdk/pull/28669#discussion_r2600245936