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

[Shakeel Butt <shakeelb@google.com>]

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?

> +{
> +       unsigned long flags;
> +
> +       local_irq_save(flags);
> +       __mod_memcg_lruvec_state(lruvec, idx, val);
> +       local_irq_restore(flags);
> +}
> +
[...]