Re: [RFC PATCH 3/3] cgroup: Do not take css_set_lock in cgroup_show_path

[Tejun Heo]

Hello,

On Fri, May 05, 2023 at 07:32:40PM +0200, Michal Koutný wrote:
> On Fri, May 05, 2023 at 05:45:58AM -1000, Tejun Heo <tj@xxxxxxxxxx> wrote:
> > > There are three relevant nodes for each cgroupfs entry:
> > > 
> > >         R ... cgroup hierarchy root
> > >         M ... mount root
> > >         C ... reader's cgroup NS root
> > > 
> > > mountinfo is supposed to show path from C to M.
> > 
> > At least for cgroup2, the path from C to M isn't gonna change once NS is
> > established, right?
> 
> Right. Although, the argument about M (when C above M or when C and M in
> different subtrees) implicitly relies on the namespace_sem.

I don't follow. Can you please elaborate a bit more?

Thanks.

-- 
tejun