RFR: 8350075: Performance difference between SegmentAllocator methods [v2]

[Maurizio Cimadamore]

On Thu, 10 Apr 2025 06:00:48 GMT, Per Minborg <pminborg at openjdk.org> wrote:

>> This PR proposes to add `@ForceInline` to the `default` methods in `SegmentAllocator` that do not already have it.
>
> Per Minborg 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:
> 
>  - Add benchmark
>  - Merge branch 'master' into ms-add-missing-force-inline
>  - Add @ForceInline to default methods

If I'm reading the latest bench results correctly -- the gain seems to be minimal. And, if somebody defines a custom arena and overrides that allocation method, there would be no way to put `FI` back in the equation. So I'm not sure how much this is worth it TBH.

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

PR Comment: https://git.openjdk.org/jdk/pull/23628#issuecomment-2794288731