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=-5.5 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 7167EC433E1 for ; Thu, 13 Aug 2020 07:45:40 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 38D0B20716 for ; Thu, 13 Aug 2020 07:45:40 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 38D0B20716 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 B7C896B000E; Thu, 13 Aug 2020 03:45:39 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id B2DB08D0002; Thu, 13 Aug 2020 03:45:39 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id A1CFA8D0001; Thu, 13 Aug 2020 03:45:39 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0182.hostedemail.com [216.40.44.182]) by kanga.kvack.org (Postfix) with ESMTP id 8B5E16B000E for ; Thu, 13 Aug 2020 03:45:39 -0400 (EDT) Received: from smtpin30.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay01.hostedemail.com (Postfix) with ESMTP id 40B93180AD806 for ; Thu, 13 Aug 2020 07:45:39 +0000 (UTC) X-FDA: 77144760798.30.crack96_0e08d9326ff2 Received: from filter.hostedemail.com (10.5.16.251.rfc1918.com [10.5.16.251]) by smtpin30.hostedemail.com (Postfix) with ESMTP id 900A5180B3C83 for ; Thu, 13 Aug 2020 07:45:38 +0000 (UTC) X-HE-Tag: crack96_0e08d9326ff2 X-Filterd-Recvd-Size: 3277 Received: from out30-45.freemail.mail.aliyun.com (out30-45.freemail.mail.aliyun.com [115.124.30.45]) by imf27.hostedemail.com (Postfix) with ESMTP for ; Thu, 13 Aug 2020 07:45:36 +0000 (UTC) X-Alimail-AntiSpam:AC=PASS;BC=-1|-1;BR=01201311R111e4;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=19;SR=0;TI=SMTPD_---0U5dIbAA_1597304727; Received: from IT-FVFX43SYHV2H.local(mailfrom:alex.shi@linux.alibaba.com fp:SMTPD_---0U5dIbAA_1597304727) by smtp.aliyun-inc.com(127.0.0.1); Thu, 13 Aug 2020 15:45:29 +0800 Subject: Re: [RFC PATCH 1/3] mm: Drop locked from isolate_migratepages_block To: Alexander Duyck Cc: yang.shi@linux.alibaba.com, lkp@intel.com, rong.a.chen@intel.com, khlebnikov@yandex-team.ru, kirill@shutemov.name, hughd@google.com, linux-kernel@vger.kernel.org, daniel.m.jordan@oracle.com, linux-mm@kvack.org, shakeelb@google.com, willy@infradead.org, hannes@cmpxchg.org, tj@kernel.org, cgroups@vger.kernel.org, akpm@linux-foundation.org, richard.weiyang@gmail.com, mgorman@techsingularity.net, iamjoonsoo.kim@lge.com References: <20200813035100.13054.25671.stgit@localhost.localdomain> <20200813040224.13054.96724.stgit@localhost.localdomain> From: Alex Shi Message-ID: <4403f572-03c3-3061-6fc4-f56e3b6d7b67@linux.alibaba.com> Date: Thu, 13 Aug 2020 15:44:51 +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: <20200813040224.13054.96724.stgit@localhost.localdomain> Content-Type: text/plain; charset=utf-8 X-Rspamd-Queue-Id: 900A5180B3C83 X-Spamd-Result: default: False [0.00 / 100.00] X-Rspamd-Server: rspam02 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: =E5=9C=A8 2020/8/13 =E4=B8=8B=E5=8D=8812:02, Alexander Duyck =E5=86=99=E9= =81=93: > - rcu_read_lock(); > - lruvec =3D mem_cgroup_page_lruvec(page, pgdat); > - > /* If we already hold the lock, we can skip some rechecking */ > - if (lruvec !=3D locked) { > - if (locked) > - unlock_page_lruvec_irqrestore(locked, flags); > + if (!lruvec || !lruvec_holds_page_lru_lock(page, lruvec)) { Ops, lruvec_holds_page_lru_lock need rcu_read_lock.=20 > + if (lruvec) > + unlock_page_lruvec_irqrestore(lruvec, flags); > =20 > + lruvec =3D mem_cgroup_page_lruvec(page, pgdat); > compact_lock_irqsave(&lruvec->lru_lock, &flags, cc); > - locked =3D lruvec; > rcu_read_unlock(); > =20 and some bugs: [ 534.564741] CPU: 23 PID: 545 Comm: kcompactd1 Kdump: loaded Tainted: G= S W 5.8.0-next-20200803-00028-g9a7ff2cd6e5c #85 [ 534.577320] Hardware name: Alibaba Alibaba Cloud ECS/Alibaba Cloud ECS= , BIOS 1.0.PL.IP.P.027.02 05/29/2020 [ 534.587693] Call Trace: [ 534.590522] dump_stack+0x96/0xd0 [ 534.594231] ___might_sleep.cold.90+0xff/0x115 [ 534.599102] kcompactd+0x24b/0x370 [ 534.602904] ? finish_wait+0x80/0x80 [ 534.606897] ? kcompactd_do_work+0x3d0/0x3d0 [ 534.611566] kthread+0x14e/0x170 [ 534.615182] ? kthread_park+0x80/0x80 [ 534.619252] ret_from_fork+0x1f/0x30 [ 535.629483] BUG: sleeping function called from invalid context at incl= ude/linux/freezer.h:57 [ 535.638691] in_atomic(): 0, irqs_disabled(): 0, non_block: 0, pid: 545= , name: kcompactd1 [ 535.647601] INFO: lockdep is turned off.