Bug#1108294: kernel 6.12 breaks cgroup awareness of openjdk 21

[Harald Dunkel <harri@afaics.de>]

Ben Hutchings wrote:
> Thank you for bringing this to our attention.
>
> I don't think it makes sense for us to re-enable cgroups v1, given that
> it has been deprecated for so long and OpenJDK itself can use v2.

You are right, it's been deprecated for quite some time, and this is
clearly a bug in openjdk, but currently there is no better version of
JDK21. I am not sure what you mean by "OpenJDK itself can use v2".

> I will look into whether we can instead provide only a /proc/cgroups
> file, which seems to be all that OpenJDK actually needed.

How is this supposed to work? Since we are talking about the host system
here you cannot know how /proc was mounted in the container, which
Container framework is involved, or whether the container is based on
Debian at all.