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[70.44.39.90]) by smtp.gmail.com with ESMTPSA id x19sm4049983qkh.42.2020.05.07.14.06.08 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 07 May 2020 14:06:09 -0700 (PDT) Date: Thu, 7 May 2020 17:05:53 -0400 From: Johannes Weiner To: Roman Gushchin Cc: Andrew Morton , Michal Hocko , 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> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200422204708.2176080-11-guro@fb.com> X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: 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 Acked-by: Johannes Weiner