From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (prime256v1) server-digest SHA256) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 589BB606A31B for ; Tue, 27 Oct 2026 00:12:37 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key, unprotected) header.d=lists.infradead.org header.i=@lists.infradead.org header.a=rsa-sha256 header.s=bombadil.20210309 header.b=k4Yw73hd; dkim=pass (2048-bit key, unprotected) header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=U6aX/Mc1 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:Reply-To:List-Subscribe: List-Help:List-Post:List-Archive:List-Unsubscribe:List-Id:Date: Content-Transfer-Encoding:Content-Type:References:In-Reply-To:Cc:To:Subject: From:Message-ID:MIME-Version:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Unsubscribe-Post:List-Owner; bh=xl+lnIz22yv+dylM+iND4dJU9HljvViAFRhFII06DTw=; b=k4Yw73hdHUZd3S1+a3RSOcJtgf YA1knVsQdk4Fz9stMpW6Aatf3sL5Q78LDeg3VEaAz+sr93qh/hLHWeErjBH6sQ7f136agvZEaAiGh Gg56v0EYTNzeMNG3iZX9X9qg+Vf0IKxgg2QIuYCFyVle7SLdRMNHdtrJKEKofKcYX6SjD6jfL1fo9 lOpFXaSJLL+Rujre3VVEXqD3uwq8tNebUd8nBx1NhUs+piV2JncKdcpHTDLFS3IPFm4jS1yWM59Ao 4LhtMiXF6EUQRtPH2+sEWcoYDQOwRg1iM6g2vJ0cWweJlHg4Y9Lh5VfeATClGkADq93s3NujALhbX cT6VBB2g==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.100.1 #2 (Red Hat Linux)) id 1xLUnt-00000003UuJ-0AEK; Tue, 27 Oct 2026 00:12:37 +0000 Received: from tor.source.kernel.org ([172.105.4.254]) by bombadil.infradead.org with esmtps (Exim 4.100.1 #2 (Red Hat Linux)) id 1xLUnr-00000003Usy-3ZCr for kexec@lists.infradead.org; Tue, 27 Oct 2026 00:12:35 +0000 Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) by tor.source.kernel.org (Postfix) with ESMTP id 499DF600DA; Tue, 27 Oct 2026 00:12:35 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 76BBB1F01825; Tue, 27 Oct 2026 00:12:32 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1793059955; bh=xl+lnIz22yv+dylM+iND4dJU9HljvViAFRhFII06DTw=; h=From:Subject:Reply-To:To:Cc:In-Reply-To:References:Date; b=U6aX/Mc1CEWj9cXl8yu64bquQqMm2m52cvjp/vBP4NRNBObXnjYgl607wKum2H+wy SIpDQ8iJp85BtuLA7lnQdDfqLAa6878oordA6i2xCZbpGKYeQLgRLi8n31MxSmuM/K eMIwuo5JSkBmhkNt3OEUvNgOm6kPfKwPCwDJmr5kepKRB7uEi/6jOQElFckWWGYN/s END+JveeOHPdnzWrR3zkl9sXsHUgZrMmKvRA/KvsfMmj45eUYpCmoWKttfMpsjbnwI hlEgznPvfPrNBspjpWyD0XG6kl7+xK/Uv9Q6BAk4zJUDEDVAh4ekkdQ2hCtmvAkN3J 2EdZfi48IFtjA== Message-ID: From: sashiko-bot@kernel.org Subject: Re: [PATCH 10/46] mm/huge_memory: fix list corruption when deferred_split_scan() races with deferred_split_folio() To: =?utf-8?b?RGF2aWQgSGlsZGVuYnJhbmQgKEFybSk=?= , "Andrew Morton" , "Johannes Weiner" , "Michal Hocko" , "Qi Zheng" , "Shakeel Butt" , "Lorenzo Stoakes" , "Kairui Song" , "Barry Song" , "Axel Rasmussen" , "Yuanchu Xie" , "Wei Xu" , "Baoquan He" , "Baolin Wang" , "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" , =?utf-8?b?TWF0dGhldyBXaWxjb3ggKE9yYWNsZSk=?= , "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: kexec@lists.infradead.org, "Josef Bacik" In-Reply-To: <20261027-fixes_core-v1-10-6f74bec9a5bb@kernel.org> References: <20261027-fixes_core-v1-0-6f74bec9a5bb@kernel.org> <20261027-fixes_core-v1-10-6f74bec9a5bb@kernel.org> Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable Date: Tue, 27 Oct 2026 00:12:32 +0000 X-BeenThere: kexec@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Archive: List-Post: List-Help: List-Subscribe: , Reply-To: sashiko-reviews@lists.linux.dev Sender: "kexec" X-Spam-Status: No, score=-11.2 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS autolearn=ham autolearn_force=no version=4.0.1 X-Spam-Checker-Version: SpamAssassin 4.0.1 (2024-03-26) on aws-us-west-2-korg-listserv-alma10-1 X-Archived-By: > Since the deferred split queue became a list_lru, the isolate callback > moves the folios it took a reference on to an on-stack list, linked > through folio->_deferred_list, and deferred_split_scan() takes them off > that list with list_del_init() without holding the list_lru lock. >=20 > deferred_split_folio() does not know about the on-stack list. It only > holds the list_lru lock when it looks at the same list_head, and it can > run for such a folio: a THP is queued when it is mapped, as a candidate > for the underused check, and is queued "again" when a part of it gets > unmapped: >=20 > CPU0 deferred_split_scan() CPU1 deferred_split_folio() > list_del_init(&folio->_deferred_list) > next->prev =3D prev > prev->next =3D next > [ ... ] >=20 > Fixes: fafaeceb89a5 ("mm: switch deferred split shrinker to list_lru") > Cc: stable@vger.kernel.org > Reported-by: Josef Bacik > Signed-off-by: David Hildenbrand (Arm) Sashiko has reviewed this patch and found no issues. --=20 Sashiko AI review =C2=B7 https://sashiko.dev/#/patchset/20261027-fixes_core= -v1-0-6f74bec9a5bb@kernel.org?part=3D10