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 Received: from lists.ozlabs.org (lists.ozlabs.org [112.213.38.117]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 7FB44C433F5 for ; Tue, 10 May 2022 04:26:32 +0000 (UTC) Received: from boromir.ozlabs.org (localhost [IPv6:::1]) by lists.ozlabs.org (Postfix) with ESMTP id 4Ky4jy6Mgkz3cB6 for ; Tue, 10 May 2022 14:26:30 +1000 (AEST) Authentication-Results: lists.ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=linux.alibaba.com (client-ip=115.124.30.57; helo=out30-57.freemail.mail.aliyun.com; envelope-from=baolin.wang@linux.alibaba.com; receiver=) Received: from out30-57.freemail.mail.aliyun.com (out30-57.freemail.mail.aliyun.com [115.124.30.57]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 4Ky4jS3plxz3bfH for ; Tue, 10 May 2022 14:26:02 +1000 (AEST) X-Alimail-AntiSpam: AC=PASS; BC=-1|-1; BR=01201311R271e4; CH=green; DM=||false|; DS=||; FP=0|-1|-1|-1|0|-1|-1|-1; HT=e01e04357; MF=baolin.wang@linux.alibaba.com; NM=1; PH=DS; RN=31; SR=0; TI=SMTPD_---0VCp29EM_1652156751; Received: from 30.15.214.13(mailfrom:baolin.wang@linux.alibaba.com fp:SMTPD_---0VCp29EM_1652156751) by smtp.aliyun-inc.com(127.0.0.1); Tue, 10 May 2022 12:25:53 +0800 Message-ID: <0db300f4-8a91-b330-5c6f-bbc63cf2f151@linux.alibaba.com> Date: Tue, 10 May 2022 12:26:32 +0800 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:91.0) Gecko/20100101 Thunderbird/91.8.1 Subject: Re: [PATCH v3 0/3] Fix CONT-PTE/PMD size hugetlb issue when unmapping or migrating To: Andrew Morton References: <20220509210404.6a43aff15d0d6b3af0741001@linux-foundation.org> From: Baolin Wang In-Reply-To: <20220509210404.6a43aff15d0d6b3af0741001@linux-foundation.org> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit X-BeenThere: linuxppc-dev@lists.ozlabs.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: dalias@libc.org, linux-ia64@vger.kernel.org, linux-sh@vger.kernel.org, linux-mips@vger.kernel.org, James.Bottomley@HansenPartnership.com, linux-mm@kvack.org, paulus@samba.org, sparclinux@vger.kernel.org, agordeev@linux.ibm.com, will@kernel.org, linux-arch@vger.kernel.org, linux-s390@vger.kernel.org, gor@linux.ibm.com, deller@gmx.de, ysato@users.osdn.me, catalin.marinas@arm.com, borntraeger@linux.ibm.com, arnd@arndb.de, hca@linux.ibm.com, songmuchun@bytedance.com, linux-arm-kernel@lists.infradead.org, tsbogend@alpha.franken.de, linux-parisc@vger.kernel.org, linux-kernel@vger.kernel.org, svens@linux.ibm.com, linuxppc-dev@lists.ozlabs.org, davem@davemloft.net, mike.kravetz@oracle.com Errors-To: linuxppc-dev-bounces+linuxppc-dev=archiver.kernel.org@lists.ozlabs.org Sender: "Linuxppc-dev" On 5/10/2022 12:04 PM, Andrew Morton wrote: > On Tue, 10 May 2022 11:45:57 +0800 Baolin Wang wrote: > >> Hi, >> >> Now migrating a hugetlb page or unmapping a poisoned hugetlb page, we'll >> use ptep_clear_flush() and set_pte_at() to nuke the page table entry >> and remap it, and this is incorrect for CONT-PTE or CONT-PMD size hugetlb >> page, > > It would be helpful to describe why it's wrong. Something like "should > use huge_ptep_clear_flush() and huge_ptep_clear_flush() for this > purpose"? Sorry for the confusing description. I described the problem explicitly in each patch's commit message. https://lore.kernel.org/all/ea5abf529f0997b5430961012bfda6166c1efc8c.1652147571.git.baolin.wang@linux.alibaba.com/ https://lore.kernel.org/all/730ea4b6d292f32fb10b7a4e87dad49b0eb30474.1652147571.git.baolin.wang@linux.alibaba.com/ > >> which will cause potential data consistent issue. This patch set >> will change to use hugetlb related APIs to fix this issue, please find >> details in each patch. Thanks. > > Is a cc:stable needed here? And are we able to identify a target for a > Fixes: tag? I think need a cc:stable tag, however I am not sure the target fixes tag, since we should trace back to the introduction of CONT-PTE/PMD hugetlb? 66b3923a1a0f ("arm64: hugetlb: add support for PTE contiguous bit")