Re: [patch 13/13] mm: memcontrol: rewrite uncharge API

From: Michal Hocko
Date: Thu Jul 24 2014 - 05:03:10 EST


On Thu 24-07-14 10:46:44, Michal Hocko wrote:
> On Wed 23-07-14 17:02:41, Johannes Weiner wrote:
[...]
> We can reduce the lookup only to lruvec==true case, no?

Dohh
s@can@should@

newpage shouldn't charged in all other cases and it would be bug.
Or am I missing something?

> Acked-by: Michal Hocko <mhocko@xxxxxxx>
>
> > ---
> > mm/memcontrol.c | 6 ++++++
> > 1 file changed, 6 insertions(+)
> >
> > diff --git a/mm/memcontrol.c b/mm/memcontrol.c
> > index b7c9a202dee9..3eaa6e83c168 100644
> > --- a/mm/memcontrol.c
> > +++ b/mm/memcontrol.c
> > @@ -6660,6 +6660,12 @@ void mem_cgroup_migrate(struct page *oldpage, struct page *newpage,
> > if (mem_cgroup_disabled())
> > return;
> >
> > + /* Page cache replacement: new page already charged? */
> > + pc = lookup_page_cgroup(newpage);
> > + if (PageCgroupUsed(pc))
> > + return;
> > +
> > + /* Re-entrant migration: old page already uncharged? */
> > pc = lookup_page_cgroup(oldpage);
> > if (!PageCgroupUsed(pc))
> > return;
> > --
> > 2.0.0
> >
>
> --
> Michal Hocko
> SUSE Labs
>
> --
> To unsubscribe, send a message with 'unsubscribe linux-mm' in
> the body to majordomo@xxxxxxxxxx For more info on Linux MM,
> see: http://www.linux-mm.org/ .
> Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>

--
Michal Hocko
SUSE Labs
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/