RFR: 8343191: Cgroup v1 subsystem fails to set subsystem path [v9]

[Severin Gehwolf]

On Wed, 11 Dec 2024 15:19:06 GMT, Sergey Chernyshev <schernyshev at openjdk.org> wrote:

>> src/hotspot/os/linux/cgroupV2Subsystem_linux.cpp line 322:
>> 
>>> 320:     } else {
>>> 321:       log_warning(os, container)("Cgroup cpu/memory controller path includes '../', detected limits won't be accurate");
>>> 322:     }
>> 
>> Please move this warning to `CgroupUtil::adjust_controller` and abort the adjustment, we don't need to issue this warning multiple times, and we'd not be able to adjust it to a path that will work. Showing the warning once should be sufficient. We shouldn't see this path in any non-moved scenarios. It would perhaps help if we included some detail why this warning is being shown. I suggest:
>> 
>> ```cgroup controller path seems to have moved (includes '.../'), detected limits won't be accurate```
>
> Would you recommand also to include the paths in that warning? Something like
> ```cgroup controller path at '/sys/fs/cgroup' seems to have moved to '../../test', detected limits won't be accurate```
> This way it will have all the necessary information to investigate customer cases.

Seems fine yes.

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

PR Review Comment: https://git.openjdk.org/jdk/pull/21808#discussion_r1880407169