Re: [PATCH v1] mm: Defines obj_cgroup_get() if CONFIG_MEMCG is not defined.

[Michal Hocko <mhocko@suse.com>]

On Wed 21-08-24 19:40:42, Sridhar, Kanchana P wrote:
> 
> > -----Original Message-----
> > From: Nhat Pham <nphamcs@gmail.com>
> > Sent: Wednesday, August 21, 2024 12:24 PM
> > To: Sridhar, Kanchana P <kanchana.p.sridhar@intel.com>
> > Cc: linux-kernel@vger.kernel.org; linux-mm@kvack.org;
> > hannes@cmpxchg.org; yosryahmed@google.com; ryan.roberts@arm.com;
> > Huang, Ying <ying.huang@intel.com>; 21cnbao@gmail.com; akpm@linux-
> > foundation.org; Zou, Nanhai <nanhai.zou@intel.com>; Feghali, Wajdi K
> > <wajdi.k.feghali@intel.com>; Gopal, Vinodh <vinodh.gopal@intel.com>
> > Subject: Re: [PATCH v1] mm: Defines obj_cgroup_get() if CONFIG_MEMCG is
> > not defined.
> > 
> > On Tue, Aug 20, 2024 at 3:50 PM Kanchana P Sridhar
> > <kanchana.p.sridhar@intel.com> wrote:
> > >
> > > This resolves an issue with obj_cgroup_get() not being defined
> > > if CONFIG_MEMCG is not defined. This causes build errors if
> > > obj_cgroup_get() is called from code that is agnostic of CONFIG_MEMCG.
> > >
> > > The patch resolves this.
> > >
> > > Signed-off-by: Kanchana P Sridhar <kanchana.p.sridhar@intel.com>
> > > ---
> > 
> > This is only exposed because of your zswap mTHP patch series right?
> > Could you include this patch as part of that series (since we don't
> > need this without that patch series), or make it clear in the change
> > log?
> 
> That's correct, Nhat. Although, it might be useful to have obj_cgroup_get()
> defined in the case where CONFIG_MEMCG is not defined. memcontrol.h
> handles obj_cgroup_put() similarly. Would it be Ok if I included a reference
> to the zswap mTHP patch series in the change log?

I would just fold it into the patch which exposes use without
CONFIG_MEMCG. We currently do not have any such user. That's why I've
asked what is this patch based on.
-- 
Michal Hocko
SUSE Labs