"Right now only the memory usage with respect to a cgroup can be controlled.
The swap space used by the tasks within a cgroup cannot be controlled."
The above is followed by:
"...This feature can be exploited by passing the kernel boot parameter "swapaccount=1" and can be disabled by passing "swapaccount=0". If the feature is enabled, an interface by name "memory.memsw.limit_in_bytes"
will be present under the memory controller...