[Devel] Re: [PATCH v3 04/13] kmem accounting basic infrastructure

[Michal Hocko]

On Thu 27-09-12 16:20:55, Glauber Costa wrote:
> On 09/27/2012 04:15 PM, Michal Hocko wrote:
> > On Wed 26-09-12 16:33:34, Tejun Heo wrote:
> > [...]
> >>>> So, this seems properly crazy to me at the similar level of
> >>>> use_hierarchy fiasco.  I'm gonna NACK on this.
> >>>
> >>> As I said: all use cases I particularly care about are covered by a
> >>> global switch.
> >>>
> >>> I am laying down my views because I really believe they make more sense.
> >>> But at some point, of course, I'll shut up if I believe I am a lone voice.
> >>>
> >>> I believe it should still be good to hear from mhocko and kame, but from
> >>> your point of view, would all the rest, plus the introduction of a
> >>> global switch make it acceptable to you?
> >>
> >> The only thing I'm whining about is per-node switch + silently
> >> ignoring past accounting, so if those two are solved, I think I'm
> >> pretty happy with the rest.
> > 
> > I think that per-group "switch" is not nice as well but if we make it
> > hierarchy specific (which I am proposing for quite some time) and do not
> > let enable accounting for a group with tasks then we get both
> > flexibility and reasonable semantic. A global switch sounds too coars to
> > me and it really not necessary.
> > 
> > Would this work with you?
> > 
> 
> How exactly would that work? AFAIK, we have a single memcg root, we
> can't have multiple memcg hierarchies in a system. Am I missing something?

Well root is so different that we could consider the first level as the
real roots for hierarchies.
-- 
Michal Hocko
SUSE Labs