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

Michal Hocko
2014-10-08T12:48:23Z

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?

> Thanks!
>
> include/linux/cgroup.h | 26 +++
> include/linux/percpu-refcount.h | 43 ++++-
> mm/memcontrol.c | 337 ++------------------------------------
> 3 files changed, 75 insertions(+), 331 deletions(-)
>

--
Michal Hocko
SUSE Labs