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 6C7A0C43215 for ; Mon, 18 Nov 2019 12:23:23 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 4E94020730 for ; Mon, 18 Nov 2019 12:23:23 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726769AbfKRMXW (ORCPT ); Mon, 18 Nov 2019 07:23:22 -0500 Received: from out30-132.freemail.mail.aliyun.com ([115.124.30.132]:44977 "EHLO out30-132.freemail.mail.aliyun.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726464AbfKRMXV (ORCPT ); Mon, 18 Nov 2019 07:23:21 -0500 X-Alimail-AntiSpam: AC=PASS;BC=-1|-1;BR=01201311R871e4;CH=green;DM=||false|;FP=0|-1|-1|-1|0|-1|-1|-1;HT=e01e01422;MF=alex.shi@linux.alibaba.com;NM=1;PH=DS;RN=38;SR=0;TI=SMTPD_---0TiTs0oQ_1574079792; Received: from IT-FVFX43SYHV2H.local(mailfrom:alex.shi@linux.alibaba.com fp:SMTPD_---0TiTs0oQ_1574079792) by smtp.aliyun-inc.com(127.0.0.1); Mon, 18 Nov 2019 20:23:13 +0800 Subject: Re: [PATCH v3 3/7] mm/lru: replace pgdat lru_lock with lruvec lock To: Shakeel Butt Cc: Cgroups , LKML , Linux MM , Andrew Morton , Mel Gorman , Tejun Heo , Hugh Dickins , Konstantin Khlebnikov , Daniel Jordan , Yang Shi , Matthew Wilcox , Johannes Weiner , 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: <1573874106-23802-1-git-send-email-alex.shi@linux.alibaba.com> <1573874106-23802-4-git-send-email-alex.shi@linux.alibaba.com> From: Alex Shi Message-ID: <3f179d84-85e2-bace-2dbc-e77f73883c71@linux.alibaba.com> Date: Mon, 18 Nov 2019 20:23:12 +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: 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 2019/11/16 下午3:03, Shakeel Butt 写道: >> +reget_lruvec: >> + lruvec = mem_cgroup_page_lruvec(page, pgdat); >> + >> /* If we already hold the lock, we can skip some rechecking */ >> - if (!locked) { >> - locked = compact_lock_irqsave(&pgdat->lru_lock, >> - &flags, cc); >> + if (lruvec != locked_lruvec) { >> + if (locked_lruvec) { >> + spin_unlock_irqrestore(&locked_lruvec->lru_lock, >> + locked_lruvec->irqflags); >> + locked_lruvec = NULL; >> + } > What guarantees the lifetime of lruvec? You should read the comment on > mem_cgroup_page_lruvec(). Have you seen the patches Hugh had shared? > Please look at the trylock_page_lruvec(). > Thanks for comments, Shakeel. lruvec lifetime is same as memcg, which allocted in mem_cgroup_alloc()->alloc_mem_cgroup_per_node_info() I have read Hugh's patchset, even not every lines. But what's point of you here? > BTW have you tested Hugh's patches? > yes, I have tried the case-lru-file-readtwice on my machine w/o containers, it show a bit more regression. Thanks Alex