Integrated: 8275055: Improve HeapRegionRemSet::split_card()

[Thomas Schatzl]

On Mon, 11 Oct 2021 15:11:12 GMT, Thomas Schatzl <tschatzl at openjdk.org> wrote:

> Hi all,
> 
>   can I have reviews for this small change that improves HeapRegionRemSet::split_card() by reducing the number of (direct and indirect) memory accesses for it. It is hard to actually measure improvements because it's only called in concurrent code. So no particular improvements measured.
> 
> It also prepares that method for virtualizing the remembered set containers, allowing arbitrarily large heap region sizes [JDK-8275056](https://bugs.openjdk.java.net/browse/JDK-8275056). This change is required then because the splitting of a card index into "region" and "card within region" should not be dependent on *heap regions*.
> 
> Testing: gha, gc/g1 local testing.
> 
> Thanks,
>   Thomas

This pull request has now been integrated.

Changeset: 7e28bdd1
Author:    Thomas Schatzl <tschatzl at openjdk.org>
URL:       https://git.openjdk.java.net/jdk/commit/7e28bdd1eb8276a5f78802febc9bd6f1cf597f55
Stats:     85 lines in 7 files changed: 82 ins; 0 del; 3 mod

8275055: Improve HeapRegionRemSet::split_card()

Reviewed-by: sjohanss, ayang

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PR: https://git.openjdk.java.net/jdk/pull/5895