On Wed, Jan 06, 2021 at 11:50:44AM -0800, Andrew Morton wrote:
> On Tue, 5 Jan 2021 20:22:39 -0800 Roman Gushchin <guro@xxxxxx> wrote:
>
> > Imran Khan reported a regression in hackbench results caused by the
> > commit f2fe7b09a52b ("mm: memcg/slab: charge individual slab objects
> > instead of pages").
>
> How large was the regression?
~16% according to Imran's data.
>
> > --- a/mm/memcontrol.c
> > +++ b/mm/memcontrol.c
> > @@ -3122,9 +3122,7 @@ void __memcg_kmem_uncharge(struct mem_cgroup *memcg, unsigned int nr_pages)
> > if (!cgroup_subsys_on_dfl(memory_cgrp_subsys))
> > page_counter_uncharge(&memcg->kmem, nr_pages);
> >
> > - page_counter_uncharge(&memcg->memory, nr_pages);
> > - if (do_memsw_account())
> > - page_counter_uncharge(&memcg->memsw, nr_pages);
> > + refill_stock(memcg, nr_pages);
> > }
>
> IOW, which kernel version(s) should we be patching?
5.9+
Thanks!
