From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.subspace.kernel.org (Postfix) with ESMTP id 47A67606A329 for ; Mon, 2 Nov 2026 07:09:52 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key, unprotected) header.d=linux.alibaba.com header.i=@linux.alibaba.com header.a=rsa-sha256 header.s=default header.b=NZ7mLZNI Received: by kanga.kvack.org (Postfix) id 6D9EC6B05B6; Mon, 2 Nov 2026 02:09:51 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 68A2C6B05B9; Mon, 2 Nov 2026 02:09:51 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 57A186B05BA; Mon, 2 Nov 2026 02:09:51 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0017.hostedemail.com [216.40.44.17]) by kanga.kvack.org (Postfix) with ESMTP id 35F546B05B6 for ; Mon, 2 Nov 2026 02:09:51 -0500 (EST) Received: from smtpin20.hostedemail.com (lb01a-stub [10.200.18.249]) by unirelay07.hostedemail.com (Postfix) with ESMTP id BF3FD160BD3 for ; Mon, 2 Nov 2026 07:09:50 +0000 (UTC) X-FDA: 85389304140.20.A7D42F6 Received: from out30-100.freemail.mail.aliyun.com (out30-100.freemail.mail.aliyun.com [115.124.30.100]) by imf23.hostedemail.com (Postfix) with ESMTP id 9CAD8140007 for ; Mon, 2 Nov 2026 07:09:44 +0000 (UTC) Authentication-Results: imf23.hostedemail.com; dkim=pass header.d=linux.alibaba.com header.s=default header.b=NZ7mLZNI; spf=pass (imf23.hostedemail.com: domain of baolin.wang@linux.alibaba.com designates 115.124.30.100 as permitted sender) smtp.mailfrom=baolin.wang@linux.alibaba.com; dmarc=pass (policy=none) header.from=linux.alibaba.com ARC-Seal: i=1; a=rsa-sha256; d=hostedemail.com; s=arc-20220608; cv=none; t=1793603387; b=7VBVJINXNjHEzrwb1TpNJL3cDSXkoUQKeSaKjPrbGqms9jsYlgfERY9ivvRO+EPnND9GoR rFD01tUbeQLJAciC69YQUkms9XvIznV4uL2Qfq6z5WofMSMACwfB0wmPJD2ziN9p9v92py FwjVyYlKkS6gek6Jt4v1DjK1rAdP3Zg= ARC-Authentication-Results: i=1; imf23.hostedemail.com; dkim=pass header.d=linux.alibaba.com header.s=default header.b=NZ7mLZNI; spf=pass (imf23.hostedemail.com: domain of baolin.wang@linux.alibaba.com designates 115.124.30.100 as permitted sender) smtp.mailfrom=baolin.wang@linux.alibaba.com; dmarc=pass (policy=none) header.from=linux.alibaba.com ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1793603387; h=from:from:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references:dkim-signature; bh=2fO+hC9G2Gl1xqrTCPgoZEeJNl9zikfHS4tc4D1yVE4=; b=IdtbPDCJiE0Sf8iG+Sm6WLAyfzIJt70UtDTkqMI130Ar7uajk1ZTh/6jxVr2XHPLY38i5P 52WN8q2xoTL2cLFN8bNv8+yIvlCeEw8M6TxhgzTeiSglimceEk8Kj3if4Y+U2KUdQ2hphi nnevVuTkwxVl6U0jpOV5agLvDis8lOE= DKIM-Signature:v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.alibaba.com; s=default; t=1793603381; h=Message-ID:Date:MIME-Version:Subject:To:From:Content-Type; bh=2fO+hC9G2Gl1xqrTCPgoZEeJNl9zikfHS4tc4D1yVE4=; b=NZ7mLZNI8uJQaeSYoIVETAzHJapvJamo75sSzNds4uSjfhDqrTaqPehrMJ60C5rszlMXPDweu4AEH4jEF1C9ZCY4BmwceyeJX4+umUKxriKfLXKKyEY/mkB4LmiFHFkr0N9gxbLqutB4xXoI6DG/bGZ22MiHdOO3XcqUwWJSKTg= X-Alimail-AntiSpam:AC=PASS;BC=-1|-1;BR=01201311R371e4;CH=green;DM=||false|;DS=||;FP=0|-1|-1|-1|0|-1|-1|-1;HT=maildocker-contentspam033037009110;MF=baolin.wang@linux.alibaba.com;NM=1;PH=DS;RN=66;SR=0;TI=SMTPD_---0XDudPio_1793603375; Received: from 30.74.144.167(mailfrom:baolin.wang@linux.alibaba.com fp:SMTPD_---0XDudPio_1793603375 cluster:ay36) by smtp.aliyun-inc.com; Mon, 02 Nov 2026 15:09:37 +0800 Message-ID: <166bcddc-1a03-421d-9cc0-92b5a0159d69@linux.alibaba.com> Date: Mon, 2 Nov 2026 15:09:35 +0800 X-Archived-By: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v3 15/47] mm/khugepaged: always recheck the pmd in try_collapse_pte_mapped_thp() To: "David Hildenbrand (Arm)" , Andrew Morton , Johannes Weiner , Michal Hocko , Qi Zheng , Shakeel Butt , Lorenzo Stoakes , Kairui Song , Barry Song , Axel Rasmussen , Yuanchu Xie , Wei Xu , Baoquan He , "Liam R. Howlett" , Vlastimil Babka , Mike Rapoport , Suren Baghdasaryan , Michal Hocko , Kees Cook , Peter Zijlstra , Jann Horn , Pedro Falcato , Hugh Dickins , Pasha Tatashin , Pratyush Yadav , "Matthew Wilcox (Oracle)" , Jan Kara , Zi Yan , Lance Yang , Rik van Riel , Harry Yoo , Alistair Popple , Nico Pache , Ryan Roberts , Dev Jain , Usama Arif , Kiryl Shutsemau , Matthew Brost , John Hubbard , Peter Xu , Will Deacon , "Aneesh Kumar K.V" , Nick Piggin , Oscar Salvador , Minchan Kim , Muchun Song , Xu Xin , Chengming Zhou , Chris Li , Kemeng Shi , Nhat Pham , Youngjun Park , Gregory Price , Joshua Hahn , Rakie Kim , Ying Huang , Jason Gunthorpe Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org, kexec@lists.infradead.org, linux-fsdevel@vger.kernel.org, linux-arch@vger.kernel.org, linux-cxl@vger.kernel.org, Josef Bacik , stable@vger.kernel.org, Muhammad Usama Anjum References: <20261031-fixes_core-v3-0-d6437171ecc3@kernel.org> <20261031-fixes_core-v3-15-d6437171ecc3@kernel.org> From: Baolin Wang In-Reply-To: <20261031-fixes_core-v3-15-d6437171ecc3@kernel.org> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit X-Stat-Signature: x4ahtx48t68h4zpjpfkpg1wszyqgqcn6 X-Spam-Status: No, score=-19.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,MAILING_LIST_MULTI,SPF_HELO_PASS,SPF_PASS, UNPARSEABLE_RELAY,USER_AGENT_SANE_1,USER_IN_DEF_DKIM_WL autolearn=unavailable autolearn_force=no version=4.0.1 X-Rspamd-Server: rspam07 X-Rspamd-Queue-Id: 9CAD8140007 X-Rspam-User: X-HE-Tag: 1793603384-490427 X-HE-Meta: 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 MyjPYGw5 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 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: X-Spam-Checker-Version: SpamAssassin 4.0.1 (2024-03-26) on aws-us-west-2-korg-listserv-alma10-1 On 10/31/26 5:39 PM, David Hildenbrand (Arm) wrote: > From: Josef Bacik > > try_collapse_pte_mapped_thp() drops the PTE lock after it has cleared the > page table, and takes the PMD lock and the PTE lock to remove it. > > In between, MADV_DONTNEED with CONFIG_PT_RECLAIM can reclaim the > page table. The pmd_same() check is supposed to handle this, but it is > only done with CONFIG_SPLIT_PTE_PTLOCKS. > > Fix it by performing the check unconditionally. > > Fix generated by an LLM and sent by Josef Bacik in private. > > Fixes: 6375e95f381e ("mm: pgtable: reclaim empty PTE page in madvise(MADV_DONTNEED)") > Cc: stable@vger.kernel.org > Signed-off-by: Josef Bacik > [ david: adjust description ] > Reviewed-by: Gregory Price (Meta) > Tested-by: Gregory Price (Meta) > Tested-by: Muhammad Usama Anjum > Signed-off-by: David Hildenbrand (Arm) > --- LGTM. Reviewed-by: Baolin Wang