Hello, Michal. On Tue, Aug 20, 2024 at 04:38:40PM +0200, Michal Koutný wrote: > On Wed, Aug 07, 2024 at 02:25:23PM GMT, Tejun Heo <tj@xxxxxxxxxx> wrote: > > +void cgroup_show_cftype(struct cftype *cft, bool show) > > +{ > > + struct cgroup_subsys *ss = cft->ss; > > + struct cgroup *root = ss ? &ss->root->cgrp : &cgrp_dfl_root.cgrp; > > Strictly speaking, this (v1) cgroup_root dereference should be guarded > with cgroup_mutex too (should be the root destroy concurrently). Ah, right. I think I might just drop this patch. Hiding and showing the interface files dynamically doesn't seem to work that well in practive (ie. it causes more production problems than it solves). Something a bit more boring like triggering a warning when a unimplemented feature is used is probably better here. Thanks. -- tejun