[lworld] RFR: 8373494: [lworld] markWord preservation for ParallelGC [v3]

[Stefan Karlsson]

On Fri, 12 Dec 2025 09:52:50 GMT, Joel Sikström <jsikstro at openjdk.org> wrote:

>> Yes, I agree, we overlooked that we had that information inside `do_addr`.
>
> The remaining_words here are the remaining words in the "from"/"source" region, while the `words_remaining()` inside `do_addr` are the words remaining in the "to"/"destination" region. We could rename remaining_words to something like `from_words_remaining`?
> 
> The reason we can't handle this in `do_addr` is because obj_size can be larger than the words we have remaining in the from region.

Ahh. Thanks for the explanation.

I wonder if you could get rid of the confusion if you changed the code to be:

      markWord mark = safe_mark_prototype(cur_addr, end_addr);

And performed the calculation hidden iside the safe_mark_protype?

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PR Review Comment: https://git.openjdk.org/valhalla/pull/1785#discussion_r2613656897