RFR: 8366881: Parallel: Obsolete HeapMaximumCompactionInterval [v2]

[Francesco Andreuzzi]

On Fri, 5 Sep 2025 09:30:45 GMT, Albert Mingkun Yang <ayang at openjdk.org> wrote:

>> Remove a produce flag that controls maximum-compaction during a full-gc. The existing criteria, such as heap usage, old-gen density, are enough for deciding maximum-compaction.
>> 
>> Test: tier1-3
>
> Albert Mingkun Yang 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 three additional commits since the last revision:
> 
>  - review
>  - Merge branch 'master' into pgc-max-compaction-obsolete
>  - pgc-max-compaction-obsolete

src/hotspot/share/gc/parallel/parallelScavengeHeap.cpp line 342:

> 340:   // No need for max-compaction in this context.
> 341:   const bool should_do_max_compaction = false;
> 342:   PSParallelCompact::invoke(clear_all_soft_refs, should_do_max_compaction);

Perhaps this might do too, without the need for an additional variable?
Suggestion:

  PSParallelCompact::invoke(clear_all_soft_refs, false /* should_do_max_compaction */);

src/hotspot/share/runtime/arguments.cpp line 571:

> 569: 
> 570:   { "PretenureSizeThreshold",       JDK_Version::undefined(), JDK_Version::jdk(26), JDK_Version::jdk(27) },
> 571:   { "HeapMaximumCompactionInterval",JDK_Version::undefined(), JDK_Version::jdk(26), JDK_Version::jdk(27) },

Maybe add a space?
Suggestion:

  { "HeapMaximumCompactionInterval", JDK_Version::undefined(), JDK_Version::jdk(26), JDK_Version::jdk(27) },

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

PR Review Comment: https://git.openjdk.org/jdk/pull/27091#discussion_r2330468557
PR Review Comment: https://git.openjdk.org/jdk/pull/27091#discussion_r2330473880