From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755254AbdJIQor (ORCPT ); Mon, 9 Oct 2017 12:44:47 -0400 Received: from out0-237.mail.aliyun.com ([140.205.0.237]:59065 "EHLO out0-237.mail.aliyun.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755201AbdJIQoo (ORCPT ); Mon, 9 Oct 2017 12:44:44 -0400 X-Alimail-AntiSpam: AC=PASS;BC=-1|-1;BR=01201311R181e4;FP=0|-1|-1|-1|0|-1|-1|-1;HT=e02c03305;MF=yang.s@alibaba-inc.com;NM=1;PH=DS;RN=8;SR=0;TI=SMTPD_---.951Gadc_1507567469; Subject: Re: [PATCH 3/3] mm: oom: show unreclaimable slab info when unreclaimable slabs > user memory To: Michal Hocko Cc: cl@linux.com, penberg@kernel.org, rientjes@google.com, iamjoonsoo.kim@lge.com, akpm@linux-foundation.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org References: <1507152550-46205-1-git-send-email-yang.s@alibaba-inc.com> <1507152550-46205-4-git-send-email-yang.s@alibaba-inc.com> <20171006093702.3ca2p6ymyycwfgbk@dhcp22.suse.cz> <20171009063316.qjmunbabyr2nzh52@dhcp22.suse.cz> <20171009063642.nykrjazifntrj5zz@dhcp22.suse.cz> From: "Yang Shi" Message-ID: Date: Tue, 10 Oct 2017 00:44:21 +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: <20171009063642.nykrjazifntrj5zz@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 10/8/17 11:36 PM, Michal Hocko wrote: > On Mon 09-10-17 08:33:16, Michal Hocko wrote: >> On Sat 07-10-17 00:37:55, Yang Shi wrote: >>> >>> >>> On 10/6/17 2:37 AM, Michal Hocko wrote: >>>> On Thu 05-10-17 05:29:10, Yang Shi wrote: >> [...] >>>>> + list_for_each_entry_safe(s, s2, &slab_caches, list) { >>>>> + if (!is_root_cache(s) || (s->flags & SLAB_RECLAIM_ACCOUNT)) >>>>> + continue; >>>>> + >>>>> + memset(&sinfo, 0, sizeof(sinfo)); >>>> >>>> why do you zero out the structure. All the fields you are printing are >>>> filled out in get_slabinfo. >>> >>> No special reason, just wipe out the potential stale data on the stack. >> >> Do not add code that has no meaning. The OOM killer is a slow path but >> that doesn't mean we should throw spare cycles out of the window. > > With this fixed and the compile fix [1] folded, feel free to add my > Acked-by: Michal Hocko Sure, thanks. I think I'd better to send out a new version so that Andrew could replace them easily. Yang > > [1] http://lkml.kernel.org/r/1507492085-42264-1-git-send-email-yang.s@alibaba-inc.com >