[jdk25u-dev] RFR: 8212084: G1: Implement UseGCOverheadLimit

[Richard Reingruber]

On Wed, 10 Dec 2025 12:18:03 GMT, Goetz Lindenmaier <goetz at openjdk.org> wrote:

> I backport this for parity with 25.0.3-oracle.
> 
> src/hotspot/share/gc/g1/g1CollectedHeap.cpp
> Deleting two blocks failed. The code is not in 25. It came by "8366865: Allocation GC Pauses Triggered after JVM has started shutdown". The original change just moved this code.  I omit adding it in the new location, too.
> 
> src/hotspot/share/gc/parallel/parallelArguments.cpp
> Deleting one block failed. The code is not in 25.
> 
> src/hotspot/share/gc/parallel/parallelScavengeHeap.cpp
> Omitted two patches that make only sense with "8338977: Parallel: Improve heap resizing heuristics"
> 
> src/hotspot/share/gc/parallel/parallelScavengeHeap.hpp
> Omitted one patch that makes only sense with "8338977: Parallel: Improve heap resizing heuristics"
> 
> Compilation stumbles, as long_term_gc_time_ratio() is not available in 25.
> This was introduced by "8359348: G1: Improve cpu usage measurements for heap sizing".
> I replace it by it's predecessor method long_term_pause_time_ratio().
> I also need a new include to make it compile. See second commit.
> 
> The new test runs with G1 and parallel GC.
> As "8338977: Parallel: Improve heap resizing heuristics" is not in 25 and
> I omitted the patches for parallelScavengeHeap.cpp form this change,
> the test does not work.  I disabled it.  See third commit.

Looks good.
Cheers, Richard.

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Marked as reviewed by rrich (Reviewer).

PR Review: https://git.openjdk.org/jdk25u-dev/pull/74#pullrequestreview-3588607497