Re: [PATCH 2/2] mm: memcontrol: account pagetables per node

[Shakeel Butt <shakeelb@google.com>]

On Mon, Nov 30, 2020 at 12:21 PM Johannes Weiner <hannes@cmpxchg.org> wrote:
>
> On Wed, Nov 25, 2020 at 04:56:03PM -0800, Shakeel Butt wrote:
> > For many workloads, pagetable consumption is significant and it makes
> > sense to expose it in the memory.stat for the memory cgroups. However at
> > the moment, the pagetables are accounted per-zone. Converting them to
> > per-node and using the right interface will correctly account for the
> > memory cgroups as well.
> >
> > Signed-off-by: Shakeel Butt <shakeelb@google.com>
>
> Agreed, this is a useful stat item to have.
>
> Just one trivial issue:
>
> > --- a/include/linux/mmzone.h
> > +++ b/include/linux/mmzone.h
> > @@ -151,7 +151,6 @@ enum zone_stat_item {
> >       NR_ZONE_UNEVICTABLE,
> >       NR_ZONE_WRITE_PENDING,  /* Count of dirty, writeback and unstable pages */
> >       NR_MLOCK,               /* mlock()ed pages found and moved off LRU */
> > -     NR_PAGETABLE,           /* used for pagetables */
> >       /* Second 128 byte cacheline */
> >       NR_BOUNCE,
> >  #if IS_ENABLED(CONFIG_ZSMALLOC)
> > @@ -206,6 +205,7 @@ enum node_stat_item {
> >  #if IS_ENABLED(CONFIG_SHADOW_CALL_STACK)
> >       NR_KERNEL_SCS_KB,       /* measured in KiB */
> >  #endif
> > +     NR_PAGETABLE,           /* used for pagetables */
> >       NR_VM_NODE_STAT_ITEMS
> >  };
>
> You need to update mm/vmstat.c::vmstat_text accordingly or
> /proc/vmstat output will be bogus.

Oh I missed that. Thanks for catching.

>
> With that fixed, please feel free to add:
> Acked-by: Johannes Weiner <hannes@cmpxchg.org>

Thanks.