From mboxrd@z Thu Jan  1 00:00:00 1970
From: Tejun Heo <tj-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org>
Subject: Re: [PATCH v6 2/3] cgroups: allow a cgroup subsystem to reject a fork
Date: Thu, 26 Mar 2015 18:18:23 -0400
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To: Aleksa Sarai <cyphar-gVpy/LI/lHzQT0dZR+AlfA@public.gmane.org>
Cc: lizefan-hv44wF8Li93QT0dZR+AlfA@public.gmane.org, mingo-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org, peterz-wEGCiKHe2LqWVfeAwA7xHQ@public.gmane.org, richard-/L3Ra7n9ekc@public.gmane.org, =?iso-8859-1?Q?Fr=E9d=E9ric?= Weisbecker <fweisbec-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>, linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, cgroups-u79uwXL29TY76Z2rM5mHXA@public.gmane.org

On Fri, Mar 27, 2015 at 08:41:05AM +1100, Aleksa Sarai wrote:
> > You can't pin css_set from inside cgroup callbacks.  It's a construct
> > which in general shouldn't be accessible outside cgroup core.
> 
> Yeah, sorry I meant css (you aren't pinning, but you're still saving under RCU
> and dealing with the association-related stuff inside post_fork).

How would that work without pinning?  What'd keep the css from going
away between pre and post?

Thanks.

-- 
tejun