Integrated: 8368006: Parallel: Skip full regions in dense prefix during Full GC

[Albert Mingkun Yang]

On Thu, 18 Sep 2025 18:00:18 GMT, Albert Mingkun Yang <ayang at openjdk.org> wrote:

> Implement skip-full-region optimization for filler related operations on dense-prefix. I constrained the filler-creation task to a single worker for simpler implementation. During the compaction phase, the most expensive part is almost always the non-dense-prefix part, so letting the rest of workers to start with the expensive tasks seems sensible.
> 
> Synthetic bms shows good reduction in full-gc time in debug build; perf-neutral for other bms (specjvm2008,specjbb2015) in release build.
> 
> Test: tier1-5

This pull request has now been integrated.

Changeset: 87307802
Author:    Albert Mingkun Yang <ayang at openjdk.org>
URL:       https://git.openjdk.org/jdk/commit/873078028b7cac1df94cd5a09e403c8537f14ba9
Stats:     96 lines in 2 files changed: 40 ins; 25 del; 31 mod

8368006: Parallel: Skip full regions in dense prefix during Full GC

Reviewed-by: gli, fandreuzzi

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PR: https://git.openjdk.org/jdk/pull/27369