Integrated: 8271163: G1 uses wrong degree of MT processing since JDK-8270169

[Thomas Schatzl]

On Fri, 23 Jul 2021 10:33:18 GMT, Thomas Schatzl <tschatzl at openjdk.org> wrote:

> Hi all,
> 
>   JDK-8270169 changed the amount of resources supplied by the CM reference processor, assuming that the CM ref processor is only ever used with the marking threads.
> This is unfortunately not true, the CM reference processor is also used by the Remark pause for discovery using the parallel gc worker threads.
> 
> This causes crashes because of the code assuming single threaded operation while it is not.
> 
> The solution proposed here is to just revert JDK-8270169 which introduced  that change. Applies cleanly.
> 
> I also added a comment in the reference processor constructor to why we need to consider both thread counts.
> 
> Thanks,
>   Thomas

This pull request has now been integrated.

Changeset: 8c8e3a0d
Author:    Thomas Schatzl <tschatzl at openjdk.org>
URL:       https://git.openjdk.java.net/jdk/commit/8c8e3a0df2dac94a2978ec86093985af47ffe330
Stats:     4 lines in 1 file changed: 2 ins; 0 del; 2 mod

8271163: G1 uses wrong degree of MT processing since JDK-8270169

Reviewed-by: kbarrett, ayang

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

PR: https://git.openjdk.java.net/jdk/pull/4888