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Cpuset
CPUsets are deprecated on Linux, and have been for some time! They are implemented in terms of version 1 control groups. Almost everything one can do with a a CPUset can be done with a version 2 control group plus the cpuset controller, but it will be better integrated with other resource controllers, and be more reliable.
Don't use CPUsets! This includes libcpuset, which is a farce, and the cgroupv1 filesystem often mounted at /dev/cpuset.
You will not be able to mount the cpuset hierarchy if the unified cgroupv2 hierarchy exists, and cpuset is present in any cgroup.subtree_control node (the mount will fail with EBUSY). Likewise, a mounted cpuset hierarchy will prevent cpuset from being added to a cgroupv2 cgroup.subtree_control (the write will fail with ENOENT).