Re: cgroup: status-quo and userland efforts

[Mike Galbraith <bitbucket@online.de>]

On Wed, 2013-06-26 at 14:20 -0700, Tejun Heo wrote: 
> Hello, Tim.
> 
> On Mon, Jun 24, 2013 at 09:07:47PM -0700, Tim Hockin wrote:
> > I really want to understand why this is SO IMPORTANT that you have to
> > break userspace compatibility?  I mean, isn't Linux supposed to be the
> > OS with the stable kernel interface?  I've seen Linus rant time and
> > time again about this - why is it OK now?
> 
> What the hell are you talking about?  Nobody is breaking userland
> interface.  A new version of interface is being phased in and the old
> one will stay there for the foreseeable future.  It will be phased out
> eventually but that's gonna take a long time and it will have to be
> something hardly noticeable.  Of course new features will only be
> available with the new interface and there will be efforts to nudge
> people away from the old one but the existing interface will keep
> working it does.

I can understand some alarm.  When I saw the below I started frothing at
the face and howling at the moon, and I don't even use the things much.

http://lists.freedesktop.org/archives/systemd-devel/2013-June/011521.html

Hierarchy layout aside, that "private property" bit says that the folks
who currently own and use the cgroups interface will lose direct access
to it.  I can imagine folks who have become dependent upon an on the fly
management agents of their own design becoming a tad alarmed.

-Mike