From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754524AbdKMTKg (ORCPT ); Mon, 13 Nov 2017 14:10:36 -0500 Received: from out0-249.mail.aliyun.com ([140.205.0.249]:37345 "EHLO out0-249.mail.aliyun.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751576AbdKMTKe (ORCPT ); Mon, 13 Nov 2017 14:10:34 -0500 X-Alimail-AntiSpam: AC=PASS;BC=-1|-1;BR=01201311R111e4;FP=0|-1|-1|-1|0|-1|-1|-1;HT=e02c03302;MF=yang.s@alibaba-inc.com;NM=1;PH=DS;RN=6;SR=0;TI=SMTPD_---.9OoH80f_1510600223; Subject: Re: [PATCH v2] fs: fsnotify: account fsnotify metadata to kmemcg To: Michal Hocko , Jan Kara Cc: amir73il@gmail.com, linux-fsdevel@vger.kernel.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org References: <1509128538-50162-1-git-send-email-yang.s@alibaba-inc.com> <20171030124358.GF23278@quack2.suse.cz> <76a4d544-833a-5f42-a898-115640b6783b@alibaba-inc.com> <20171031101238.GD8989@quack2.suse.cz> <20171109135444.znaksm4fucmpuylf@dhcp22.suse.cz> From: "Yang Shi" Message-ID: <10924085-6275-125f-d56b-547d734b6f4e@alibaba-inc.com> Date: Tue, 14 Nov 2017 03:10:22 +0800 User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.12; rv:52.0) Gecko/20100101 Thunderbird/52.2.1 MIME-Version: 1.0 In-Reply-To: <20171109135444.znaksm4fucmpuylf@dhcp22.suse.cz> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 11/9/17 5:54 AM, Michal Hocko wrote: > [Sorry for the late reply] > > On Tue 31-10-17 11:12:38, Jan Kara wrote: >> On Tue 31-10-17 00:39:58, Yang Shi wrote: > [...] >>> I do agree it is not fair and not neat to account to producer rather than >>> misbehaving consumer, but current memcg design looks not support such use >>> case. And, the other question is do we know who is the listener if it >>> doesn't read the events? >> >> So you never know who will read from the notification file descriptor but >> you can simply account that to the process that created the notification >> group and that is IMO the right process to account to. > > Yes, if the creator is de-facto owner which defines the lifetime of > those objects then this should be a target of the charge. > >> I agree that current SLAB memcg accounting does not allow to account to a >> different memcg than the one of the running process. However I *think* it >> should be possible to add such interface. Michal? > > We do have memcg_kmem_charge_memcg but that would require some plumbing > to hook it into the specific allocation path. I suspect it uses kmalloc, > right? Yes. I took a look at the implementation and the callsites of memcg_kmem_charge_memcg(). It looks it is called by: * charge kmem to memcg, but it is charged to the allocator's memcg * allocate new slab page, charge to memcg_params.memcg I think this is the plumbing you mentioned, right? Thanks, Yang >