Re: [PATCH -v2 next 4/4] memcg: factor out stat(event)/stat_local(event_local) reading functions

[Shakeel Butt]

On Tue, Jan 14, 2025 at 06:45:20PM +0000, Roman Gushchin wrote:
> On Tue, Jan 14, 2025 at 12:25:19PM +0000, Chen Ridong wrote:
> > From: Chen Ridong <chenridong@xxxxxxxxxx>
> > 
> > The only difference between 'lruvec_page_state' and
> > 'lruvec_page_state_local' is that they read 'state' and 'state_local',
> > respectively. Factor out an inner functions to make the code more concise.
> > Do the same for reading 'memcg_page_stat' and 'memcg_events'.
> > 
> > Signed-off-by: Chen Ridong <chenridong@xxxxxxxxxx>
> > ---
> >  mm/memcontrol.c | 72 +++++++++++++++++++++----------------------------
> >  1 file changed, 30 insertions(+), 42 deletions(-)
> > 
> > diff --git a/mm/memcontrol.c b/mm/memcontrol.c
> > index b10e0a8f3375..14541610cad0 100644
> > --- a/mm/memcontrol.c
> > +++ b/mm/memcontrol.c
> > @@ -375,7 +375,8 @@ struct lruvec_stats {
> >  	long state_pending[NR_MEMCG_NODE_STAT_ITEMS];
> >  };
> >  
> > -unsigned long lruvec_page_state(struct lruvec *lruvec, enum node_stat_item idx)
> > +static unsigned long __lruvec_page_state(struct lruvec *lruvec,
> > +		enum node_stat_item idx, bool local)
> >  {
> >  	struct mem_cgroup_per_node *pn;
> >  	long x;
> > @@ -389,7 +390,8 @@ unsigned long lruvec_page_state(struct lruvec *lruvec, enum node_stat_item idx)
> >  		return 0;
> >  
> >  	pn = container_of(lruvec, struct mem_cgroup_per_node, lruvec);
> > -	x = READ_ONCE(pn->lruvec_stats->state[i]);
> > +	x = local ? READ_ONCE(pn->lruvec_stats->state_local[i]) :
> > +		    READ_ONCE(pn->lruvec_stats->state[i]);
> >  #ifdef CONFIG_SMP
> >  	if (x < 0)
> >  		x = 0;
> > @@ -397,27 +399,16 @@ unsigned long lruvec_page_state(struct lruvec *lruvec, enum node_stat_item idx)
> >  	return x;
> >  }
> >  
> > +
> > +unsigned long lruvec_page_state(struct lruvec *lruvec, enum node_stat_item idx)
> > +{
> > +	return __lruvec_page_state(lruvec, idx, false);
> > +}
> 
> I'd move these wrapper function definitions to memcontrol.h and make them
> static inline.

+1

> 
> Other than that, lgtm.
> 
> Thank you!