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From:   Shakeel Butt <shakeelb@google.com>
Date:   Fri, 2 Apr 2021 18:10:48 -0700
Message-ID: <CALvZod4O-Y2LBQhEKQjWShm_dd6VNi0GUuev7PmMw_6GqGWFPA@mail.gmail.com>
Subject: Re: [PATCH] mm: memcontrol: fix forget to obtain the ref to objcg in split_page_memcg
To:     Andrew Morton <akpm@linux-foundation.org>
Cc:     Roman Gushchin <guro@fb.com>, Miaohe Lin <linmiaohe@huawei.com>,
        Muchun Song <songmuchun@bytedance.com>,
        LKML <linux-kernel@vger.kernel.org>,
        Linux MM <linux-mm@kvack.org>,
        Xiongchun duan <duanxiongchun@bytedance.com>,
        Christian Borntraeger <borntraeger@de.ibm.com>,
        Johannes Weiner <hannes@cmpxchg.org>,
        Michal Hocko <mhocko@kernel.org>,
        Vladimir Davydov <vdavydov.dev@gmail.com>
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On Fri, Apr 2, 2021 at 6:04 PM Andrew Morton <akpm@linux-foundation.org> wrote:
>
> On Wed, 31 Mar 2021 20:35:02 -0700 Roman Gushchin <guro@fb.com> wrote:
>
> > On Thu, Apr 01, 2021 at 11:31:16AM +0800, Miaohe Lin wrote:
> > > On 2021/4/1 11:01, Muchun Song wrote:
> > > > Christian Borntraeger reported a warning about "percpu ref
> > > > (obj_cgroup_release) <= 0 (-1) after switching to atomic".
> > > > Because we forgot to obtain the reference to the objcg and
> > > > wrongly obtain the reference of memcg.
> > > >
> > > > Reported-by: Christian Borntraeger <borntraeger@de.ibm.com>
> > > > Signed-off-by: Muchun Song <songmuchun@bytedance.com>
> > >
> > > Thanks for the patch.
> > > Is a Fixes tag needed?
> >
> > No, as the original patch hasn't been merged into the Linus's tree yet.
> > So the fix can be simply squashed.
>
> Help.  Which is "the original patch"?

"mm: memcontrol: use obj_cgroup APIs to charge kmem pages"