Examine the output of the command:

The names in the first column represent cgroup subsystems that are currently attached to any cgroup hierarchy regardless of whether they are mounted or unmounted. 

freezer, net, cls, and perf_event are group subsystems and they are attached to unmounted cgroup hierarchies. The second column represents the arbitrary system-assigned cgroup hierarchy number. 

spuset, cpu, memory cpuacct, and blkio are cgroup subsystems and they are attached to mounted cgroup hierarchies. The second column represents the mount point of the cgroup hierarchy. 

freezer, net_cls, and perf_event are group subsystems and they are attached to mounted cgroup hierarchies. The numbers in the second column represent the number of cgroups in each cgroup hierarchy. 

cpuset, cpu, memory, cpuacct, and blkio are cgroup subsystems and they are attached to unmounted cgroup hierarchies. The second column represents the configuration file for the corresponding cgroup hierarchy.