RFR: 8373714: Shenandoah: Register heuristic penalties following a degenerated GC [v6]

[William Kemper]

On Wed, 7 Jan 2026 18:19:35 GMT, Kelvin Nilsen <kdnilsen at openjdk.org> wrote:

>> Add a triggering penalty when we execute degenerated GC cycle.
>
> Kelvin Nilsen has updated the pull request with a new target base due to a merge or a rebase. The incremental webrev excludes the unrelated changes brought in by the merge/rebase. The pull request contains nine additional commits since the last revision:
> 
>  - Combine successful and unsuccessful into single method: report_degenerated()
>  - remove gratuitous blank line
>  - Merge remote-tracking branch 'jdk/master' into add-degen-penalty
>  - touch file to force tests
>  - Merge remote-tracking branch 'jdk/master' into add-degen-penalty
>  - Merge remote-tracking branch 'jdk/master' into add-degen-penalty
>  - refactor for reviewer requests
>  - remove redundant code
>  - Increase heuristic penalties following degenerated GC

Looks good to integrate, assuming testing pipelines pass.

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Marked as reviewed by wkemper (Reviewer).

PR Review: https://git.openjdk.org/jdk/pull/28834#pullrequestreview-3636442278