RFR: 8339162: [REDO] JDK-8338440 Parallel: Improve fragmentation mitigation in Full GC

[Guoxiong Li]

On Mon, 4 Nov 2024 10:55:45 GMT, Albert Mingkun Yang <ayang at openjdk.org> wrote:

> This PR consists of two commits, the original and bug-fix.
> 
> The original patch calculates the dest-count for the preceding live words incorrectly -- `preceding_destination` can be on region-boundary.
> 
> Test: TEST=gc/TestSoftReferencesBehaviorOnOOME.java fails ~4/100 without the fix but passes with the fix.

Looks good. Nice found. The `region_align_up`  is not the `next_region_start_address`.

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Marked as reviewed by gli (Reviewer).

PR Review: https://git.openjdk.org/jdk/pull/21872#pullrequestreview-2417193301