RFR: 8294844: Improve G1 young gen length revise trigger

[Kim Barrett]

On Tue, 11 Oct 2022 13:56:17 GMT, Thomas Schatzl <tschatzl at openjdk.org> wrote:

> Hi all,
> 
>   please review this change that makes actual young gen length revising unconditional.
> 
> This solves the following issues:
> * currently young gen revising would only shrink the young gen, which would waste time available in the pause.
> * young gen sizing is not only dependent on remembered sets (it has been gated on changes to the remembered set only) but also significantly on the pending cards length. This means that in some cases necessary revising would not occur, being a cause for greatly missing pause times.
> 
> Depends on PR#10651, please review that one first.
> 
> Testing: Testing: gha, local testing, tier1-5 with other changes in this patch series, perf testing with other changes in this patch series
> 
> Thanks,
>   Thomas

Looks good.

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Marked as reviewed by kbarrett (Reviewer).

PR: https://git.openjdk.org/jdk/pull/10652