[Devel] [PATCH 1/2] memcg: fix memcg_size() calculation

[Michal Hocko]

On Tue 17-12-13 11:48:20, Glauber Costa wrote:
> On Mon, Dec 16, 2013 at 8:47 PM, Michal Hocko <mhocko at suse.cz> wrote:
> > On Sat 14-12-13 12:15:33, Vladimir Davydov wrote:
> >> The mem_cgroup structure contains nr_node_ids pointers to
> >> mem_cgroup_per_node objects, not the objects themselves.
> >
> > Ouch! This is 2k per node which is wasted. What a shame I haven't
> > noticed this back then when reviewing 45cf7ebd5a033 (memcg: reduce the
> > size of struct memcg 244-fold)
> >
> IIRC, they weren't pointers back then. I think they were embedded in
> the structure, and I let
> them embedded.
> My mind may be tricking me, but I think I recall that Johannes changed
> them to pointers
> in a later time. No ?

It was wrapped by mem_cgroup_lru_info back then but the memcg_size
hasn't changed after 54f72fe022d9 (memcg: clean up memcg->nodeinfo) so
the missing * was there since 45cf7ebd5a033

> In any case, this is correct.

-- 
Michal Hocko
SUSE Labs