[LTP] [PATCH] controllers/cpuset: Make mount failure TCONF

[Cyril Hrubis]

Hi!
> > It appears that if the subsystem is available under V2 then mounting
> > the V1 can fail. Probably when the V2 has processes assigned to a
> > group it controls.
> 
> Sounds likely, but it would be good to check this in the kernel code or with
> kernel cgroup developers.

I'm pretty sure that controller can be used either in v1, or in v2 but
not from both at the same time by choice. Some of the changes between v1
and v2 are incompatible so this couldn't work either way.

I think that once the controller name is written to
/sys/fs/cgroup/unified/cgroup.subtree_controll mounting it to v1 should
fail, so maybe we should just try to grep the fail instead and exit the
test with TCONF if we found the controller bound to v2 already.

-- 
Cyril Hrubis
chrubis@suse.cz