Re: [PATCH v3 01/19] mm: memcg: factor out memcg- and lruvec-level changes out of __mod_lruvec_state()

[Vlastimil Babka]

On 4/22/20 10:46 PM, Roman Gushchin 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@xxxxxx>

Reviewed-by: Vlastimil Babka <vbabka@xxxxxxx>

Nit below:

> --- a/mm/memcontrol.c
> +++ b/mm/memcontrol.c
> @@ -713,30 +713,14 @@ parent_nodeinfo(struct mem_cgroup_per_node *pn, int nid)
>  	return mem_cgroup_nodeinfo(parent, nid);
>  }
>  
> -/**
> - * __mod_lruvec_state - update lruvec memory statistics
> - * @lruvec: the lruvec
> - * @idx: the stat item
> - * @val: delta to add to the counter, can be negative
> - *
> - * The lruvec is the intersection of the NUMA node and a cgroup. This
> - * function updates the all three counters that are affected by a
> - * change of state at this level: per-node, per-cgroup, per-lruvec.
> - */
> -void __mod_lruvec_state(struct lruvec *lruvec, enum node_stat_item idx,
> -			int val)
> +void __mod_memcg_lruvec_state(struct lruvec *lruvec, enum node_stat_item idx,
> +			      int val)
>  {
>  	pg_data_t *pgdat = lruvec_pgdat(lruvec);

Looks like the pgdat can now be moved into the MEMCG_CHARGE_BATCH if().