Re: + mm-memcontrol-correct-the-nr_anon_thps-counter-of-hierarchical-memcg-fix.patch added to -mm tree

Re: + mm-memcontrol-correct-the-nr_anon_thps-counter-of-hierarchical-memcg-fix.patch added to -mm tree

[Michal Hocko]

On Mon 26-10-20 14:08:01, Andrew Morton wrote:
[...]
> From: Andrew Morton <akpm@linux-foundation.org>
> Subject: mm-memcontrol-correct-the-nr_anon_thps-counter-of-hierarchical-memcg-fix
> 
> fix printk warning
> 
> Cc: Johannes Weiner <hannes@cmpxchg.org>
> Cc: Michal Hocko <mhocko@suse.com>
> Cc: zhongjiang-ali <zhongjiang-ali@linux.alibaba.com>
> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
> ---
> 
>  mm/memcontrol.c |    2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> --- a/mm/memcontrol.c~mm-memcontrol-correct-the-nr_anon_thps-counter-of-hierarchical-memcg-fix
> +++ a/mm/memcontrol.c
> @@ -4107,7 +4107,7 @@ static int memcg_stat_show(struct seq_fi
>  		if (memcg1_stats[i] == NR_ANON_THPS)
>  			nr *= HPAGE_PMD_NR;
>  #endif
> -		seq_printf(m, "total_%s %llu\n", memcg1_stat_names[i],
> +		seq_printf(m, "total_%s %lu\n", memcg1_stat_names[i],
>  						nr * PAGE_SIZE);

Shouldn't we cast to u64 instead? 32b systems with a lot of memory are
quite rare but going over 4G here is not something unimaginable. The
similar is true for other counters.
-- 
Michal Hocko
SUSE Labs

Re: + mm-memcontrol-correct-the-nr_anon_thps-counter-of-hierarchical-memcg-fix.patch added to -mm tree

[Andrew Morton]

On Tue, 27 Oct 2020 08:21:57 +0100 Michal Hocko <mhocko@suse.com> wrote:

> > --- a/mm/memcontrol.c~mm-memcontrol-correct-the-nr_anon_thps-counter-of-hierarchical-memcg-fix
> > +++ a/mm/memcontrol.c
> > @@ -4107,7 +4107,7 @@ static int memcg_stat_show(struct seq_fi
> >  		if (memcg1_stats[i] == NR_ANON_THPS)
> >  			nr *= HPAGE_PMD_NR;
> >  #endif
> > -		seq_printf(m, "total_%s %llu\n", memcg1_stat_names[i],
> > +		seq_printf(m, "total_%s %lu\n", memcg1_stat_names[i],
> >  						nr * PAGE_SIZE);
> 
> Shouldn't we cast to u64 instead? 32b systems with a lot of memory are
> quite rare but going over 4G here is not something unimaginable. The
> similar is true for other counters.

Sure..

--- a/mm/memcontrol.c~mm-memcontrol-correct-the-nr_anon_thps-counter-of-hierarchical-memcg-fix-fix
+++ a/mm/memcontrol.c
@@ -4119,8 +4119,8 @@ static int memcg_stat_show(struct seq_fi
 		if (memcg1_stats[i] == NR_ANON_THPS)
 			nr *= HPAGE_PMD_NR;
 #endif
-		seq_printf(m, "total_%s %lu\n", memcg1_stat_names[i],
-						nr * PAGE_SIZE);
+		seq_printf(m, "total_%s %llu\n", memcg1_stat_names[i],
+						(u64)nr * PAGE_SIZE);
 	}
 
 	for (i = 0; i < ARRAY_SIZE(memcg1_events); i++)
_