I plan to work w/cgroups in OpenSuSE 12.1 but have some basic misunderstandings.

1) Do I understand correctly that (by default) after OpenSuSE 12.1 booting there is 2 active cgroups hierarchies - systemd and cpuset ?

2) boot.cgroup service in /etc/init.d is used for mounting of /sys/fs/cgroup.
chkconfig says that boot.cgroup is off (chkconfig forwarded request to systemd confirms - "no active"), but

/etc/init.d/boot.cgroup status

says that this service is "running". And /sys/fs/cgroup really contains some subdirectories for systemd etc.

Why there is such contradiction ?

3) /usr/src/linux/Documentation/cgroups as also OpenSuSE System Analysis and Tuning Guide
describes creation and management of cgroups using /sys/fs/cgroup

But there is other sources w/examples of cgroups creation at other mounting points, for example in /mnt or even somewhere in /dev.
Do I understand correctly that cgroup hierachy may be created (mounted) at any appropriate point in my filesystems ?

BTW, do I unerstand correctly that

mount -t tmpfs .... /sys/fs/cgroup

has no immediate relation to cgroups itself - it's simple the command which creates some appropriate mounting point for subsequent mounting of cgroups ?

4) ps xawf -e -o pid,users,cgroup,args

gives me

PID USER CGROUP COMMAND
2 root 9:perf_event:/?8:blkio:/?7 [kthreadd]
3 root \_ 9:perf_event:/?8:blkio \_ [ksoftirqd/0]
..............................
1345 root \_ 9:perf_event:/?8:blkio \_ [kworker/1:0]
1 root 9:perf_event:/?8:blkio:/?7 /sbin/init
318 root 9:perf_event:/?8:blkio:/?7 /sbin/udevd
1203 root \_ 9:perf_event:/?8:blkio \_ /sbin/udevd
1207 root \_ 9:perf_event:/?8:blkio \_ /sbin/udevd
596 root 9:perf_event:/?8:blkio:/?7 /lib/systemd/systemd-stdout-syslog-bridge
....................................
1009 root 9:perf_event:/?8:blkio:/?7 /usr/sbin/sshd -o PidFile=/var/run/sshd.init.pid
1035 root 9:perf_event:/?8:blkio:/?7 /usr/sbin/console-kit-daemon --no-daemon
1102 root 9:perf_event:/?8:blkio:/?7 /usr/lib/polkit-1/polkitd --no-debug

what means that all the processes belongs to blkio cgroup. Why ?