Re: [PATCH v6 01/19] mm: memcg: factor out memcg- and lruvec-level changes out of __mod_lruvec_state()

[Roman Gushchin <guro@fb.com>]

On Tue, Jun 16, 2020 at 07:59:40PM -0700, Shakeel Butt wrote:
> On Tue, Jun 16, 2020 at 7:50 PM Roman Gushchin <guro@fb.com> wrote:
> >
> > On Tue, Jun 16, 2020 at 06:52:09PM -0700, Shakeel Butt wrote:
> > > On Mon, Jun 8, 2020 at 4:07 PM Roman Gushchin <guro@fb.com> wrote:
> > > >
> > > > To convert memcg and lruvec slab counters to bytes there must be
> > > > a way to change these counters without touching node counters.
> > > > Factor out __mod_memcg_lruvec_state() out of __mod_lruvec_state().
> > > >
> > > > Signed-off-by: Roman Gushchin <guro@fb.com>
> > > > Acked-by: Johannes Weiner <hannes@cmpxchg.org>
> > > > Reviewed-by: Vlastimil Babka <vbabka@suse.cz>
> > > > ---
> > > >  include/linux/memcontrol.h | 17 +++++++++++++++
> > > >  mm/memcontrol.c            | 43 +++++++++++++++++++++-----------------
> > > >  2 files changed, 41 insertions(+), 19 deletions(-)
> > > >
> > > > diff --git a/include/linux/memcontrol.h b/include/linux/memcontrol.h
> > > > index bbf624a7f5a6..93dbc7f9d8b8 100644
> > > > --- a/include/linux/memcontrol.h
> > > > +++ b/include/linux/memcontrol.h
> > > > @@ -679,11 +679,23 @@ static inline unsigned long lruvec_page_state_local(struct lruvec *lruvec,
> > > >         return x;
> > > >  }
> > > >
> > > > +void __mod_memcg_lruvec_state(struct lruvec *lruvec, enum node_stat_item idx,
> > > > +                             int val);
> > > >  void __mod_lruvec_state(struct lruvec *lruvec, enum node_stat_item idx,
> > > >                         int val);
> > > >  void __mod_lruvec_slab_state(void *p, enum node_stat_item idx, int val);
> > > >  void mod_memcg_obj_state(void *p, int idx, int val);
> > > >
> > > > +static inline void mod_memcg_lruvec_state(struct lruvec *lruvec,
> > > > +                                         enum node_stat_item idx, int val)
> > >
> > > Is this function used in later patches? Any benefit introducing it
> > > here instead of in the patch where it is used for the first time?
> >
> > Yes, it's used in "mm: memcg/slab: charge individual slab objects instead of pages".
> >
> > It's a fairly large patchset with many internal dependencies, so there is
> > always a trade-off between putting everything into a single patch, which is
> > hard to review, and splitting out some changes, which make not much sense
> > without seeing the whole picture.
> >
> > In this particular case splitting out a formal and easy-to-verify change makes
> > the actual non-trivial patch smaller and hopefully easier for a review.
> >
> > But of course it's all subjective.
> >
> > Thanks!
> 
> I am fine with that.
> 
> Reviewed-by: Shakeel Butt <shakeelb@google.com>

Thank you! Appreciate it!