Hello Tejun, At some point, I'd like to add some details about cgroups v2 "thread mode" to the cgroup(7) manual page. I think I understand most of the details by now, but there's one question I still can't work out an answer to: why does the "domain invalid" cgroup type exist?
I did find the July 2017 mail thread "[PATCH 5/6] cgroup: implement cgroup v2 thread support" (https://marc.info/?t=150025735500001&r=1&w=2) where this cgroup type was discussed, but I must admit that I still don't get it. Instead of converting cgroups under a threaded subtree to "domain invalid" type, why can't they just be turned straight into "threaded" type? I guess another way of asking this question is: what possibilities does manually switching each "domain invalid" cgroup to "threaded" allow that wouldn't be allowed by immediately making all of the cgroups in a threaded subtree "threaded"? Cheers, Michael -- Michael Kerrisk Linux man-pages maintainer; http://www.kernel.org/doc/man-pages/ Linux/UNIX System Programming Training: http://man7.org/training/