Re: [patch 0/3] mm: memcontrol: eliminate charge reparenting

Johannes Weiner
2014-10-08T14:17:54Z

On Wed, Oct 08, 2014 at 02:48:23PM +0200, Michal Hocko wrote:
> On Sat 20-09-14 16:00:32, Johannes Weiner wrote:
> > Hi,
> >
> > we've come a looong way when it comes to the basic cgroups model, and
> > the recent changes there open up a lot of opportunity to make drastic
> > simplifications to memory cgroups as well.
> >
> > The decoupling of css from the user-visible cgroup, word-sized per-cpu
> > css reference counters, and css iterators that include offlined groups
> > means we can take per-charge css references, continue to reclaim from
> > offlined groups, and so get rid of the error-prone charge reparenting.
> >
> > Combined with the higher-order reclaim fixes, lockless page counters,
> > and memcg iterator simplification I sent on Friday, the memory cgroup
> > core code is finally no longer the biggest file in mm/. Yay!
>
> Yeah, the code reduction (as per the diffstat - I didn't get to the code
> yet) seems really promising.

:)

> > These patches are based on mmotm + the above-mentioned changes
>
> > + Tj's percpu-refcount conversion to atomic_long_t.
>
> This is https://lkml.org/lkml/2014/9/20/11 right?

Yep, exactly. All these moving parts are now in -next, though, so as
soon as Andrew flushes his tree for 3.18, I'll rebase and resubmit.

Thanks!