Re: [PATCH] V2 sched, autogroup: fix crash on reboot when autogroup is disabled

[Mike Galbraith <efault@gmx.de>]

On Mon, 2012-10-29 at 10:42 +0800, Xiaotian Feng wrote:

> I'm okay with the removal of runtime enable/disable autogroup. But can
> we simply remove
> these two knobs that is already exposed to user space since 2.6.38 ?
> So we can't cat /proc/<pid>/autogroup
> or echo <nice level> > /proc/<pid>/autogroup anymore even if autogroup is on?

I should have never made those knobs, as it's against the whole idea of
automatic no muss no fuss group scheduling.  If you want knobs, you want
full cgroups, so I think we should call this a fix opportunity.

If the knobs are seen as being cast in stone, I'll do the full move for
the on/off switch instead, and there will be no user visible change. I'd
rather not do that.  This way, it's really out of the way when disabled,
smaller and simpler is better for this feature.

It's a dinky little sidelines feature, so let's just quietly make kaboom
go away, non-functional on/off go away, along with the silly knobs which
will make kaboom unless you jump through hoops just to keep them alive. 

-Mike