RFR: 8199407: Skip Rebuild Remset Phase if there are no rebuild candidates [v3]

[Stefan Johansson]

On Fri, 16 Apr 2021 14:24:06 GMT, Ivan Walulya <iwalulya at openjdk.org> wrote:

>> Hi all,
>> 
>> Please review this change that skips the rebuild remset phase and the associated updates after rebuild, If during Remark, G1 finds that there are no remembered sets to rebuild.
>> 
>> Test: tier1-5
>
> Ivan Walulya has updated the pull request incrementally with one additional commit since the last revision:
> 
>   change comment

Looks good, only a minor nit regarding a comment.

src/hotspot/share/gc/g1/g1ConcurrentMark.hpp line 460:

> 458:   // set phase at all.
> 459:   HeapWord* volatile* _top_at_rebuild_starts;
> 460:   // If true, then Remark pause selected regions for rebuilding.

Suggestion:

  // True when Remark pause selected regions for rebuilding.

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Marked as reviewed by sjohanss (Reviewer).

PR: https://git.openjdk.java.net/jdk/pull/3434