From mboxrd@z Thu Jan  1 00:00:00 1970
From: Vladimir Davydov <vdavydov.dev@gmail.com>
Subject: Re: [PATCH v5 7/7] mm: fix /proc/kpagecgroup interface for slab pages
Date: Tue, 28 May 2019 20:38:16 +0300
Message-ID: <20190528173815.2km65nchedfumslt@esperanza>
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To: Roman Gushchin <guro@fb.com>
Cc: Andrew Morton <akpm@linux-foundation.org>, linux-mm@kvack.org, linux-kernel@vger.kernel.org, kernel-team@fb.com, Johannes Weiner <hannes@cmpxchg.org>, Michal Hocko <mhocko@kernel.org>, Rik van Riel <riel@surriel.com>, Shakeel Butt <shakeelb@google.com>, Christoph Lameter <cl@linux.com>, cgroups@vger.kernel.org, Waiman Long <longman@redhat.com>

On Tue, May 21, 2019 at 01:07:35PM -0700, Roman Gushchin wrote:
> Switching to an indirect scheme of getting mem_cgroup pointer for
> !root slab pages broke /proc/kpagecgroup interface for them.
> 
> Let's fix it by learning page_cgroup_ino() how to get memcg
> pointer for slab pages.
> 
> Reported-by: Shakeel Butt <shakeelb@google.com>
> Signed-off-by: Roman Gushchin <guro@fb.com>
> Reviewed-by: Shakeel Butt <shakeelb@google.com>
> ---
>  mm/memcontrol.c  |  5 ++++-
>  mm/slab.h        | 25 +++++++++++++++++++++++++
>  mm/slab_common.c |  1 +
>  3 files changed, 30 insertions(+), 1 deletion(-)

What about mem_cgroup_from_kmem, see mm/list_lru.c?
Shouldn't we fix it, too?