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=-10.5 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,MENTIONS_GIT_HOSTING, NICE_REPLY_A,SPF_HELO_NONE,SPF_PASS,UNPARSEABLE_RELAY,USER_AGENT_SANE_1 autolearn=unavailable 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 B3083C433E0 for ; Mon, 20 Jul 2020 07:30:26 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 8146220729 for ; Mon, 20 Jul 2020 07:30:26 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 8146220729 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 0CD156B0003; Mon, 20 Jul 2020 03:30:26 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 07CA66B0005; Mon, 20 Jul 2020 03:30:26 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id E87C36B0006; Mon, 20 Jul 2020 03:30:25 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0065.hostedemail.com [216.40.44.65]) by kanga.kvack.org (Postfix) with ESMTP id CF3F66B0003 for ; Mon, 20 Jul 2020 03:30:25 -0400 (EDT) Received: from smtpin04.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay04.hostedemail.com (Postfix) with ESMTP id 417F81D40EF for ; Mon, 20 Jul 2020 07:30:25 +0000 (UTC) X-FDA: 77057631210.04.metal31_3e02cd026f23 Received: from filter.hostedemail.com (10.5.16.251.rfc1918.com [10.5.16.251]) by smtpin04.hostedemail.com (Postfix) with ESMTP id 1DB2380058E1 for ; Mon, 20 Jul 2020 07:30:25 +0000 (UTC) X-HE-Tag: metal31_3e02cd026f23 X-Filterd-Recvd-Size: 4560 Received: from out30-130.freemail.mail.aliyun.com (out30-130.freemail.mail.aliyun.com [115.124.30.130]) by imf19.hostedemail.com (Postfix) with ESMTP for ; Mon, 20 Jul 2020 07:30:23 +0000 (UTC) X-Alimail-AntiSpam:AC=PASS;BC=-1|-1;BR=01201311R221e4;CH=green;DM=||false|;DS=||;FP=0|-1|-1|-1|0|-1|-1|-1;HT=e01e01358;MF=alex.shi@linux.alibaba.com;NM=1;PH=DS;RN=17;SR=0;TI=SMTPD_---0U3DnCGw_1595230215; Received: from IT-FVFX43SYHV2H.local(mailfrom:alex.shi@linux.alibaba.com fp:SMTPD_---0U3DnCGw_1595230215) by smtp.aliyun-inc.com(127.0.0.1); Mon, 20 Jul 2020 15:30:16 +0800 Subject: Re: [PATCH v16 00/22] 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, yang.shi@linux.alibaba.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 References: <1594429136-20002-1-git-send-email-alex.shi@linux.alibaba.com> Message-ID: <04a2ad99-5d88-a300-6430-7a8da0946f04@linux.alibaba.com> Date: Mon, 20 Jul 2020 15:30:14 +0800 User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.15; rv:68.0) Gecko/20100101 Thunderbird/68.7.0 MIME-Version: 1.0 In-Reply-To: <1594429136-20002-1-git-send-email-alex.shi@linux.alibaba.com> Content-Type: text/plain; charset=utf-8 X-Rspamd-Queue-Id: 1DB2380058E1 X-Spamd-Result: default: False [0.00 / 100.00] X-Rspamd-Server: rspam04 Content-Transfer-Encoding: quoted-printable X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: I am preparing/testing the patch v17 according comments from Hugh Dickins and Alexander Duyck.=20 Many thanks for line by line review and patient suggestion! Please drop me any more comments or concern of any patches! Thanks a lot! Alex =E5=9C=A8 2020/7/11 =E4=B8=8A=E5=8D=888:58, Alex Shi =E5=86=99=E9=81=93: > The new version which bases on v5.8-rc4. Add 2 more patchs: > 'mm/thp: remove code path which never got into' > 'mm/thp: add tail pages into lru anyway in split_huge_page()' > and modified 'mm/mlock: reorder isolation sequence during munlock' >=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 > The patchset includes 3 parts: > 1, some code cleanup and minimum optimization as a preparation. > 2, use TestCleanPageLRU as page isolation's precondition > 3, replace per node lru_lock with per memcg per node lru_lock >=20 > Following Daniel Jordan's suggestion, I have run 208 'dd' with on 104 > containers on a 2s * 26cores * HT box with a modefied case: > https://git.kernel.org/pub/scm/linux/kernel/git/wfg/vm-scalability.git/= tree/case-lru-file-readtwice > With this patchset, the readtwice performance increased about 80% > in concurrent containers. >=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 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!