Re: [PATCH v2 3/7] memcg: reduce memory for the lruvec and memcg stats

From: Shakeel Butt
Date: Fri Apr 26 2024 - 21:16:45 EST


On Fri, Apr 26, 2024 at 05:51:23PM -0700, Yosry Ahmed wrote:
> On Fri, Apr 26, 2024 at 5:37 PM Shakeel Butt <shakeel.butt@xxxxxxxxx> wrote:
> >
> > At the moment, the amount of memory allocated for stats related structs
> > in the mem_cgroup corresponds to the size of enum node_stat_item.
> > However not all fields in enum node_stat_item has corresponding memcg
> > stats. So, let's use indirection mechanism similar to the one used for
> > memcg vmstats management.
>
> Just curious, does the indirection table cause any noticeable
> performance impact? My guess is no, but the update paths are usually
> very performance sensitive.
>
> I guess lkp will shout at us if there are any noticeable regressions.

Yeah and that is the reason I made the indirection table smaller (i.e.
int8_t) to keep more entries in a single cacheline.