linux-kernel - Re: [RFC] cgroup: deprecate clone

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <20121105192636.GG19354@mtj.dyndns.org>
Date:	Mon, 5 Nov 2012 11:26:36 -0800
From:	Tejun Heo <tj@...nel.org>
To:	Serge Hallyn <serge.hallyn@...onical.com>
Cc:	Glauber Costa <glommer@...allels.com>, rjw@...k.pl,
	linux-pm@...r.kernel.org, fweisbec@...il.com,
	containers@...ts.linux-foundation.org,
	linux-kernel@...r.kernel.org, mhocko@...e.cz,
	cgroups@...r.kernel.org
Subject: Re: [RFC] cgroup: deprecate clone_children

Hello, Serge.

On Mon, Nov 05, 2012 at 01:17:14PM -0600, Serge Hallyn wrote:
> > As this is unnecessary feature with very limited use and awkward in
> 
> clone_children is currently required by lxc.  Of course lxc could
> manually set the .cpus and .mems in the newly created child, but if
> those interfaces or others like it ever change (i.e. any new ones which
> must be set before a task can join a cgroup) we'll get into yet more of
> a rats nets of code to support different kernel versions.

If lxc is using it, this will have to stay then.  I'll try to make it
a cpuset specific thing.

> (Just as an idea, if there was a way to generically tell from the list
> of files in my cgroups dir which files need to be initialized before a
> task can join, I think that would suffice.  Maybe a cgroups.needssetup
> file which right now contains 'cpuset.mems\ncpuset.cpus'. Then if we
> find a file we don't recognize in there we can throw an intelligent
> error, or guess at duplicating the parent value.)

Hmmm... I think the root problem is that different controllers don't
agree on the way they inherit configurations from parents.  cgroup
really is a trainwreck.  :(

I don't know whether "needssetup" is the right way to deal with it.
I'll think more about it.

> > co-mounted use cases, let's try to deprecate it.  Whine on the mount
> > option and accesses to cgroupfs knobs.
> > 
> > Signed-off-by: Tejun Heo <tj@...nel.org>
> > Cc: Glauber Costa <glommer@...allels.com>
> > Cc: Peter Zijlstra <peterz@...radead.org>
> > ---
> > Glauber, I think this is more befitting change for .post_clone().  If
> 
> What do you mean by that?  That he is working on a patch-set which will
> remove post_clone and this belongs there, or that there is a proposed
> alternative?

The former.  There was a patchset from Glauber updating ->post_clone()
(which didn't change the behavior).

Thanks.

-- 
tejun
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/