From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-2.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,UNPARSEABLE_RELAY,USER_AGENT_SANE_1 autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id E0092C43603 for ; Tue, 17 Dec 2019 13:11:29 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id BCF57206EC for ; Tue, 17 Dec 2019 13:11:29 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728010AbfLQNL2 (ORCPT ); Tue, 17 Dec 2019 08:11:28 -0500 Received: from out30-132.freemail.mail.aliyun.com ([115.124.30.132]:36181 "EHLO out30-132.freemail.mail.aliyun.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726962AbfLQNL2 (ORCPT ); Tue, 17 Dec 2019 08:11:28 -0500 X-Alimail-AntiSpam: AC=PASS;BC=-1|-1;BR=01201311R171e4;CH=green;DM=||false|;DS=||;FP=0|-1|-1|-1|0|-1|-1|-1;HT=e01e04394;MF=alex.shi@linux.alibaba.com;NM=1;PH=DS;RN=38;SR=0;TI=SMTPD_---0TlCXr4r_1576588278; Received: from IT-FVFX43SYHV2H.local(mailfrom:alex.shi@linux.alibaba.com fp:SMTPD_---0TlCXr4r_1576588278) by smtp.aliyun-inc.com(127.0.0.1); Tue, 17 Dec 2019 21:11:19 +0800 Subject: Re: [PATCH v6 02/10] mm/lru: replace pgdat lru_lock with lruvec lock To: Matthew Wilcox Cc: cgroups@vger.kernel.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, akpm@linux-foundation.org, mgorman@techsingularity.net, tj@kernel.org, hughd@google.com, khlebnikov@yandex-team.ru, daniel.m.jordan@oracle.com, yang.shi@linux.alibaba.com, shakeelb@google.com, hannes@cmpxchg.org, Michal Hocko , Vladimir Davydov , Roman Gushchin , Chris Down , Thomas Gleixner , Vlastimil Babka , Qian Cai , Andrey Ryabinin , "Kirill A. Shutemov" , =?UTF-8?B?SsOpcsO0bWUgR2xpc3Nl?= , Andrea Arcangeli , David Rientjes , "Aneesh Kumar K.V" , swkhack , "Potyra, Stefan" , Mike Rapoport , Stephen Rothwell , Colin Ian King , Jason Gunthorpe , Mauro Carvalho Chehab , Peng Fan , Nikolay Borisov , Ira Weiny , Kirill Tkhai , Yafang Shao References: <1576488386-32544-1-git-send-email-alex.shi@linux.alibaba.com> <1576488386-32544-3-git-send-email-alex.shi@linux.alibaba.com> <20191216121427.GZ32169@bombadil.infradead.org> <286c11c2-480f-37d6-e9fe-91822f862cd6@linux.alibaba.com> <20191217021613.GB32169@bombadil.infradead.org> From: Alex Shi Message-ID: Date: Tue, 17 Dec 2019 21:11:18 +0800 User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.15; rv:60.0) Gecko/20100101 Thunderbird/60.9.1 MIME-Version: 1.0 In-Reply-To: <20191217021613.GB32169@bombadil.infradead.org> Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 在 2019/12/17 上午10:16, Matthew Wilcox 写道: >>> You still didn't fix this function. Go back and look at my comment from >>> the last time you sent this patch set. >>> >> Sorry for the misunderstanding. I guess what your want is fold the patch 9th into this, is that right? >> Any comments for the 9th patch? > I didn't get as far as looking at the ninth patch because I saw this > one was wrong and stopped looking. This is not the first time *with > this patch set* that you've been told to *fix the patch*, not submit > something that's broken and fix it in a later patch. > > I'll look at patch 9 later. Thanks a lot for the nice cocaching and quick response! What the problem for me here is I didn't find a bug here. From the commit_charge's explanations and mem_cgroup_commit_charge comments, as well as call path when lrucare is ture, The lock is just to guard the task migration(which would be lead to move_account) So, It's just a clean up to give up locking when !PageLRU in patch 9. And even w/o patch 9, the page just locked root_mem_cgroup's lru_lock, same as old function does, while the page isn't on any LRU. Useless, but it's still safe. Do you mind to point out anything else I missed? Thanks a lot! Alex