[systemd-devel] No cgroups in cpu,cpuacct despite autogrouping

[Jan Engelhardt]

In my kernel, there is CONFIG_SCHED_AUTOGROUP=y set. I believe that since
systemd is capable of, and is doing grouping on its own, the kernel option has
no effect. This seems reflected in /sys/fs/cgroups/cpu,cpuacct having
no subdirectories:

12:34 ares40:../cgroup/cpu,cpuacct > ls -Fax
./                   ../                  cgroup.clone_children cgroup.procs
cgroup.sane_behavior cpu.cfs_period_us    cpu.cfs_quota_us      cpu.rt_period_us
cpu.rt_runtime_us    cpu.shares           cpu.stat              cpuacct.stat
cpuacct.usage        cpuacct.usage_percpu notify_on_release     release_agent
tasks


As a result of this, all processes get equal shares, rather than all
SID groups getting equal shares, causing BOINC to outmonopolize VirtualBox:


/$ systemd-cgls
├─1 /usr/lib/systemd/systemd --switched-root --system --deserialize 20
[...]
└─user.slice
  └─user-25121.slice
    ├─session-3.scope
    │ ├─  376 ../../projects/boinc.fzk.de_poem/poempp_2.21_x86_64-pc-linux-gn...
    │ ├─ 2200 ../../projects/boinc.fzk.de_poem/poempp_2.21_x86_64-pc-linux-gn...
    │ ├─ 2578 ../../projects/boinc.fzk.de_poem/poempp_2.21_x86_64-pc-linux-gn...
    │ ├─ 2826 ../../projects/boinc.fzk.de_poem/poempp_2.21_x86_64-pc-linux-gn...
    │ ├─ 3162 ../../projects/boinc.fzk.de_poem/poempp_2.21_x86_64-pc-linux-gn...
    │ ├─ 3697 SCREEN
    │ ├─ 3698 -/bin/bash
    │ ├─ 6070 ../../projects/boinc.fzk.de_poem/poempp_2.21_x86_64-pc-linux-gn...
    │ ├─ 6554 ../../projects/boinc.fzk.de_poem/poempp_2.21_x86_64-pc-linux-gn...
    │ ├─14171 /usr/lib/virtualbox/VBoxXPCOMIPCD
    │ ├─14176 /usr/lib/virtualbox/VBoxSVC --auto-shutdown
    │ ├─14255 /usr/lib/virtualbox/VBoxNetDHCP --ip-address 192.168.100.100 --...
    │ ├─25859 boinc
    │ └─30167 ../../projects/boinc.fzk.de_poem/poempp_2.21_x86_64-pc-linux-gn...


How would one re-enable the SID-style cpuacct grouping with systemd?