Re: [PATCH v3] memcg, kmem: further deprecate kmem.limit_in_bytes

[Shakeel Butt]

On Tue, Oct 19, 2021 at 12:51 PM Andrew Morton
<akpm@xxxxxxxxxxxxxxxxxxxx> wrote:
>
> On Tue, 19 Oct 2021 08:34:08 -0700 Shakeel Butt <shakeelb@xxxxxxxxxx> wrote:
>
> > The deprecation process of kmem.limit_in_bytes started with the commit
> > 0158115f702 ("memcg, kmem: deprecate kmem.limit_in_bytes") which also
> > explains in detail the motivation behind the deprecation. To summarize,
> > it is the unexpected behavior on hitting the kmem limit. This patch
> > moves the deprecation process to the next stage by disallowing to set
> > the kmem limit. In future we might just remove the kmem.limit_in_bytes
> > file completely.
> >
> > ...
> >
> > @@ -3791,10 +3766,8 @@ static ssize_t mem_cgroup_write(struct kernfs_open_file *of,
> >                       ret = mem_cgroup_resize_max(memcg, nr_pages, true);
> >                       break;
> >               case _KMEM:
> > -                     pr_warn_once("kmem.limit_in_bytes is deprecated and will be removed. "
> > -                                  "Please report your usecase to linux-mm@xxxxxxxxx if you "
> > -                                  "depend on this functionality.\n");
> > -                     ret = memcg_update_kmem_max(memcg, nr_pages);
> > +                     /* kmem.limit_in_bytes is deprecated. */
> > +                     ret = -ENOTSUPP;
> >                       break;
> >               case _TCP:
> >                       ret = memcg_update_tcp_max(memcg, nr_pages);
>
> checkpatch said "ENOTSUPP is not a SUSV4 error code, prefer EOPNOTSUPP"?

I should have run checkpatch and Andrew, please replace ENOTSUPP with
EOPNOTSUPP. Thanks for catching this.