Bug#803013: systemd should not destroy application created cgroups

[paul.szabo at sydney.edu.au]

severity 803013 critical
tag 803013 - moreinfo unreproducible + confirmed
thanks

Dear Michael,

You did not reply for a week, so I am trying to set tags myself.

Also, while doing this, am trying to set severity back to "critical":
this bug does break unrelated software.

---

For the record: the following steps will reproduce the issue, on a
freshly-installed jessie machine:

 - Run command
     dpkg-reconfigure libpam-runtime
   and de-select the
     [ ] Register user sessions in the systemd control group hierarchy
   option; then reboot.
 - Log in to the machine; probably not via GDM3 as that might not work
   at all; not via getty as then the issue will not show(?!!); but log
   in via XDM, or via telnetd or sshd.
 - Become root (log in as such, or use su).
 - As root, do commands:
     # Set things up
     mkdir /sys/fs/cgroup/cpu/mytest
     echo $$ > /sys/fs/cgroup/cpu/mytest/tasks
     # Check it is there
     grep . /sys/fs/cgroup/cpu/mytest/tasks
     # Do the systemd thing
     systemctl daemon-reload
     systemctl start anacron
     # See it gone
     grep . /sys/fs/cgroup/cpu/mytest/tasks

Cheers, Paul

Paul Szabo   psz at maths.usyd.edu.au   http://www.maths.usyd.edu.au/u/psz/
School of Mathematics and Statistics   University of Sydney    Australia