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Date:   Thu, 7 May 2020 17:05:53 -0400
From:   Johannes Weiner <hannes@cmpxchg.org>
To:     Roman Gushchin <guro@fb.com>
Cc:     Andrew Morton <akpm@linux-foundation.org>,
        Michal Hocko <mhocko@kernel.org>, linux-mm@kvack.org,
        kernel-team@fb.com, linux-kernel@vger.kernel.org
Subject: Re: [PATCH v3 10/19] mm: memcg/slab: deprecate memory.kmem.slabinfo
Message-ID: <20200507210553.GE161043@cmpxchg.org>
References: <20200422204708.2176080-1-guro@fb.com>
 <20200422204708.2176080-11-guro@fb.com>
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On Wed, Apr 22, 2020 at 01:46:59PM -0700, Roman Gushchin wrote:
> Deprecate memory.kmem.slabinfo.
> 
> An empty file will be presented if corresponding config options are
> enabled.
> 
> The interface is implementation dependent, isn't present in cgroup v2,
> and is generally useful only for core mm debugging purposes. In other
> words, it doesn't provide any value for the absolute majority of users.
> 
> A drgn-based replacement can be found in tools/cgroup/slabinfo.py .
> It does support cgroup v1 and v2, mimics memory.kmem.slabinfo output
> and also allows to get any additional information without a need
> to recompile the kernel.
> 
> If a drgn-based solution is too slow for a task, a bpf-based tracing
> tool can be used, which can easily keep track of all slab allocations
> belonging to a memory cgroup.
> 
> Signed-off-by: Roman Gushchin <guro@fb.com>

Acked-by: Johannes Weiner <hannes@cmpxchg.org>