On Fri, Jun 19, 2020 at 6:14 PM Roman Gushchin <g...@fb.com> wrote: > > On Sat, Jun 20, 2020 at 09:00:40AM +0800, Zefan Li wrote: > > I think so, though I'm not familiar with the bfp cgroup code. > > > > > If so, we might wanna fix it in a different way, > > > just checking if (!(css->flags & CSS_NO_REF)) in cgroup_bpf_put() > > > like in cgroup_put(). It feels more reliable to me. > > > > > > > Yeah I also have this idea in my mind. > > I wonder if the following patch will fix the issue?
Interesting, AFAIU, this refcnt is for bpf programs attached to the cgroup. By this suggestion, do you mean the root cgroup does not need to refcnt the bpf programs attached to it? This seems odd, as I don't see how root is different from others in terms of bpf programs which can be attached and detached in the same way. I certainly understand the root cgroup is never gone, but this does not mean the bpf programs attached to it too. What am I missing? Thanks.
