Re: [GIT PULL] kdbus for 4.1-rc1

Michal Schmidt
2015-04-15T14:49:14Z

On 04/15/2015 09:31 AM, Mike Galbraith wrote:
> it seems [systemd] has now mandated group scheduling.

What makes you think so? Was it the fact that by default you have a
populated /sys/fs/cgroup/cpu/ hierarchy? This is either because some
unit requests the use of the cpu controller using one of the CPU*=
directives from systemd.resource-control(5), or (perhaps more likely)
because there is a privileged unit with Delegate=yes. The most likely
candidate is user@0.service, and so you could try preventing it from
starting:
systemctl mask user@0.service

Note that systemd still works without group scheduling or any cgroup
subsystems enabled in the kernel:

$ grep GROUP .config
CONFIG_CGROUPS=y
# CONFIG_CGROUP_DEBUG is not set
# CONFIG_CGROUP_FREEZER is not set
# CONFIG_CGROUP_DEVICE is not set
# CONFIG_CGROUP_CPUACCT is not set
# CONFIG_CGROUP_HUGETLB is not set
# CONFIG_CGROUP_PERF is not set
# CONFIG_CGROUP_SCHED is not set
# CONFIG_BLK_CGROUP is not set
# CONFIG_SCHED_AUTOGROUP is not set
# CONFIG_NETFILTER_XT_MATCH_CGROUP is not set
# CONFIG_NETFILTER_XT_MATCH_DEVGROUP is not set
# CONFIG_NET_CLS_CGROUP is not set
# CONFIG_CGROUP_NET_PRIO is not set
# CONFIG_CGROUP_NET_CLASSID is not set

Michal