[Date Prev][Date Next] [Thread Prev][Thread Next] [Date Index] [Thread Index]

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



On Thu, 2025-06-26 at 20:40 +0200, Harald Dunkel wrote:
> 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".

OpenJDK (from v11 onwards) appears to use v2 of the cgroups API if
available, and only mistakenly relied on /proc/cgroups for detection of
which controllers are enabled.

> > 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.

We have to assume that /proc/cgroups and cgroupfs are exposed to the
container, otherwise none of this detection could have worked before...

Ben.

-- 
Ben Hutchings
Quantity is no substitute for quality, but it's the only one we've got.

Attachment: signature.asc
Description: This is a digitally signed message part


Reply to: