cgroup freezer

From Documentation/cgroups/freezer-subsystem.txt, the following words describe the purpose of cgroups freezer: "The cgroup freezer is useful to batch job management system which start and stop sets of tasks in order to schedule the resources of a machine according to the desires of a system administrator." IMHO, when system load is high, administrator could freeze some of cpu-hogged tasks in favor of more important ones, once system is most likely to be idle, frozen tasks could be thaw back on line. I don't know this idea is right or wrong, can somebody give me some hints about practical usage of cgroup freezer? thanks -- I am a slow learner but I will keep trying to fight for my dreams! --bill