RFR: 8373714: Shenandoah: Register heuristic penalties following a degenerated GC [v2]

[William Kemper]

On Tue, 16 Dec 2025 16:57:53 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 incrementally with one additional commit since the last revision:
> 
>   refactor for reviewer requests

src/hotspot/share/gc/shenandoah/shenandoahDegeneratedGC.cpp line 322:

> 320:   } else {
> 321:     _generation->heuristics()->record_unsuccessful_degenerated();
> 322:   }

Suggestion:

  policy->record_degenerated(_generation->is_young(), _abbreviated, progress);
   _generation->heuristics()->record_success_degenerated();
  if (progress) {
    heap->notify_gc_progress();
  } else if (!heap->mode()->is_generational() || policy->generational_should_upgrade_degenerated_gc()) {
    // Upgrade to full GC, register full-GC impact on heuristics.
    op_degenerated_futile();
  }

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PR Review Comment: https://git.openjdk.org/jdk/pull/28834#discussion_r2624207680