Integrated: 8354517: Parallel: JDK-8339668 causes up to 3.7x slowdown in openjdk.bench.vm.gc.systemgc

[Albert Mingkun Yang]

On Thu, 22 May 2025 06:34:07 GMT, Albert Mingkun Yang <ayang at openjdk.org> wrote:

> Before JDK-8339668, full-gc marking array-chunk size uses `ObjArrayMarkingStride`. This patch restores the old behavior (performance).
> 
> The fix is extract out the chunk-size from `PartialArraySplitter` and use the either `ParGCArrayScanChunk` or `ObjArrayMarkingStride`, depending on the context -- the former is used during young-gc while the latter full-gc.
> 
> Test: tier1-3; checked perf regression is gone

This pull request has now been integrated.

Changeset: 36f6d155
Author:    Albert Mingkun Yang <ayang at openjdk.org>
URL:       https://git.openjdk.org/jdk/commit/36f6d155e3b9d0b279be33414573217ea38551ac
Stats:     9 lines in 5 files changed: 3 ins; 0 del; 6 mod

8354517: Parallel: JDK-8339668 causes up to 3.7x slowdown in openjdk.bench.vm.gc.systemgc

Reviewed-by: tschatzl, aboldtch, zgu

-------------

PR: https://git.openjdk.org/jdk/pull/25382