I created a cgroup manually under the cgroups v2 hierarchy on the Linux system. I am running Ubuntu 22.04 with 6.1.25 Linux kernel if that matters.

These are the steps are followed as root:

Step 1: mkdir /sys/fs/cgroup/test_group
Step 2: echo "+cpu" > cgroup.subtree_control

I get the following error after executing step 2:

bash: echo: write error: No such file or directory

I do have all the permissions required to execute.