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=-5.2 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,NICE_REPLY_A,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 A5455C4742C for ; Mon, 16 Nov 2020 03:47:11 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 19E6022280 for ; Mon, 16 Nov 2020 03:47:10 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 19E6022280 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=linux.alibaba.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 237996B0036; Sun, 15 Nov 2020 22:47:10 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 1C2426B005D; Sun, 15 Nov 2020 22:47:10 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 0B0096B0068; Sun, 15 Nov 2020 22:47:10 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0151.hostedemail.com [216.40.44.151]) by kanga.kvack.org (Postfix) with ESMTP id CE2646B0036 for ; Sun, 15 Nov 2020 22:47:09 -0500 (EST) Received: from smtpin06.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay03.hostedemail.com (Postfix) with ESMTP id 5BE328249980 for ; Mon, 16 Nov 2020 03:47:09 +0000 (UTC) X-FDA: 77488895778.06.snail53_3816ab127325 Received: from filter.hostedemail.com (10.5.16.251.rfc1918.com [10.5.16.251]) by smtpin06.hostedemail.com (Postfix) with ESMTP id 36BF41003800F for ; Mon, 16 Nov 2020 03:47:09 +0000 (UTC) X-HE-Tag: snail53_3816ab127325 X-Filterd-Recvd-Size: 4783 Received: from out30-130.freemail.mail.aliyun.com (out30-130.freemail.mail.aliyun.com [115.124.30.130]) by imf40.hostedemail.com (Postfix) with ESMTP for ; Mon, 16 Nov 2020 03:47:07 +0000 (UTC) X-Alimail-AntiSpam:AC=PASS;BC=-1|-1;BR=01201311R141e4;CH=green;DM=||false|;DS=||;FP=0|-1|-1|-1|0|-1|-1|-1;HT=alimailimapcm10staff010182156082;MF=alex.shi@linux.alibaba.com;NM=1;PH=DS;RN=21;SR=0;TI=SMTPD_---0UFSqqZF_1605498418; Received: from IT-FVFX43SYHV2H.local(mailfrom:alex.shi@linux.alibaba.com fp:SMTPD_---0UFSqqZF_1605498418) by smtp.aliyun-inc.com(127.0.0.1); Mon, 16 Nov 2020 11:46:59 +0800 Subject: Re: [PATCH v21 00/19] per memcg lru lock From: Alex Shi To: akpm@linux-foundation.org, mgorman@techsingularity.net, tj@kernel.org, hughd@google.com, khlebnikov@yandex-team.ru, daniel.m.jordan@oracle.com, willy@infradead.org, hannes@cmpxchg.org, lkp@intel.com, linux-mm@kvack.org, linux-kernel@vger.kernel.org, cgroups@vger.kernel.org, shakeelb@google.com, iamjoonsoo.kim@lge.com, richard.weiyang@gmail.com, kirill@shutemov.name, alexander.duyck@gmail.com, rong.a.chen@intel.com, mhocko@suse.com, vdavydov.dev@gmail.com, shy828301@gmail.com References: <1604566549-62481-1-git-send-email-alex.shi@linux.alibaba.com> Message-ID: Date: Mon, 16 Nov 2020 11:45:51 +0800 User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.15; rv:68.0) Gecko/20100101 Thunderbird/68.12.0 MIME-Version: 1.0 In-Reply-To: <1604566549-62481-1-git-send-email-alex.shi@linux.alibaba.com> Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable X-Bogosity: Ham, tests=bogofilter, spamicity=0.000002, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: Hi Andrew, With all patches are acked-by Hugh and Johannes, and full testing from LK= P, is this patchset ready for more testing on linux-next? or anything still = need be improved? Thanks Alex =E5=9C=A8 2020/11/5 =E4=B8=8B=E5=8D=884:55, Alex Shi =E5=86=99=E9=81=93: > This version rebase on next/master 20201104, with much of Johannes's > Acks and some changes according to Johannes comments. And add a new pat= ch > v21-0006-mm-rmap-stop-store-reordering-issue-on-page-mapp.patch to supp= ort > v21-0007. >=20 > This patchset followed 2 memcg VM_WARN_ON_ONCE_PAGE patches which were > added to -mm tree yesterday. > =20 > Many thanks for line by line review by Hugh Dickins, Alexander Duyck an= d > Johannes Weiner. >=20 > So now this patchset includes 3 parts: > 1, some code cleanup and minimum optimization as a preparation.=20 > 2, use TestCleanPageLRU as page isolation's precondition. > 3, replace per node lru_lock with per memcg per node lru_lock. >=20 > Current lru_lock is one for each of node, pgdat->lru_lock, that guard f= or > lru lists, but now we had moved the lru lists into memcg for long time.= Still > using per node lru_lock is clearly unscalable, pages on each of memcgs = have > to compete each others for a whole lru_lock. This patchset try to use p= er > lruvec/memcg lru_lock to repleace per node lru lock to guard lru lists,= make > it scalable for memcgs and get performance gain. >=20 > Currently lru_lock still guards both lru list and page's lru bit, that'= s ok. > but if we want to use specific lruvec lock on the page, we need to pin = down > the page's lruvec/memcg during locking. Just taking lruvec lock first m= ay be > undermined by the page's memcg charge/migration. To fix this problem, w= e could > take out the page's lru bit clear and use it as pin down action to bloc= k the > memcg changes. That's the reason for new atomic func TestClearPageLRU. > So now isolating a page need both actions: TestClearPageLRU and hold th= e > lru_lock. >=20 > The typical usage of this is isolate_migratepages_block() in compaction= .c > we have to take lru bit before lru lock, that serialized the page isola= tion > in memcg page charge/migration which will change page's lruvec and new=20 > lru_lock in it. >=20 > The above solution suggested by Johannes Weiner, and based on his new m= emcg=20 > charge path, then have this patchset. (Hugh Dickins tested and contribu= ted much > code from compaction fix to general code polish, thanks a lot!). >=20 > Daniel Jordan's testing show 62% improvement on modified readtwice case > on his 2P * 10 core * 2 HT broadwell box on v18, which has no much diff= erent > with this v20. > https://lore.kernel.org/lkml/20200915165807.kpp7uhiw7l3loofu@ca-dmjorda= n1.us.oracle.com/ >=20 > Thanks Hugh Dickins and Konstantin Khlebnikov, they both brought this > idea 8 years ago, and others who give comments as well: Daniel Jordan,=20 > Mel Gorman, Shakeel Butt, Matthew Wilcox, Alexander Duyck etc. >=20 > Thanks for Testing support from Intel 0day and Rong Chen, Fengguang Wu, > and Yun Wang. Hugh Dickins also shared his kbuild-swap case. Thanks!