RFR: 8338977: Parallel: Improve heap resizing heuristics [v3]

[Guoxiong Li]

On Sun, 18 May 2025 18:01:44 GMT, Guoxiong Li <gli at openjdk.org> wrote:

>> 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 five additional commits since the last revision:
>> 
>>  - review
>>  - Merge branch 'master' into pgc-size-policy
>>  - review
>>  - Merge branch 'master' into pgc-size-policy
>>  - pgc-size-policy
>
> src/hotspot/share/gc/parallel/parallelScavengeHeap.cpp line 343:
> 
>> 341:       if (_gc_overhead_counter >= GCOverheadLimitThreshold) {
>> 342:         return nullptr;
>> 343:       }
> 
> Returning `nullptr` means the `OutOfMemoryException` should be thrown later. Is it good to add a `error` level log here?

And notice: we can't identify the `OutOfMemoryException` whether because `gc overhead limit is exceeded`.

As I pointed out before: `the field MemAllocator::Allocation::_overhead_limit_exceeded are not used now`.

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PR Review Comment: https://git.openjdk.org/jdk/pull/25000#discussion_r2094591384