[jdk21u-dev] RFR: 8343191: Cgroup v1 subsystem fails to set subsystem path

[Goetz Lindenmaier]

On Fri, 22 Aug 2025 06:14:26 GMT, lingjun-cg <duke at openjdk.org> wrote:

>> There are follow-ups for this to prepare. Please prepare dependent PRs for those: [JDK-8352926](https://bugs.openjdk.org/browse/JDK-8352926), JDK-8360533, JDK-8354475, JDK-8351382
>
>> There are follow-ups for this to prepare. Please prepare dependent PRs for those: [JDK-8352926](https://bugs.openjdk.org/browse/JDK-8352926), JDK-8360533, JDK-8354475, JDK-8351382
> 
> Thanks for your review.  Because  the JDK-8352926, JDK-8360533, JDK-8354475, JDK-8351382 depends on current JDK-8343191,  and the 4 JBS issues have dependency on each other, so I merge all of them into the current PR.
> I'm not sure is it OK? If not, maybe need create 5 PRs one by one according the dependency between PRs.
> If that, please review the first current PR, then I create others.
> 
> Also there has a test failed: tools/javac/patterns/SOEDeeplyNestedBlocksTest.java
> But it has nothing to do with current PR.

Hi @lingjun-cg 
for the follow-ups:
I ran this PR through our testing. It makes jdk/internal/platform/docker/TestDockerMemoryMetricsSubgroup.java fail.
You can not push it this way.

Yes, it's not nice to merge 5 changes into one, especially if the changes backport clean.  The merged change will require a review, and that review will be unnecessary complex.

If the follow up is a very simple change, and a bad bug like one that kills the build, you should include it right away.
If the follow-up is urgent, like the one that probably fixes TestDockerMemoryMetricsSubgroup, make a dependent pull request so that you can push them right after each other.
To do so check out origin/pr/2109  and place the backport on top of that.  

For other follow-ups, 1. inform in your approval comment that they are needed, and 2. backport them in a timely manner.  Don't let us approvers discover such a situation!!

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PR Comment: https://git.openjdk.org/jdk21u-dev/pull/2109#issuecomment-3213248524