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 70226606A31A for ; Fri, 30 Oct 2026 03:40:20 +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=FTuYC1ZV; dkim=pass (2048-bit key, unprotected) header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=I5GuMBeM 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=Bv38qew6Wsr0ojuGu26s7yan/OuyYioSrYN2sDRrsjM=; b=FTuYC1ZV5LW8VHbX5QjEZPkVfE AcU81sOn+YTW41wiLkdDUVnlbD4jyx/cgSKc5SXCxFDAwgY1FQ0qQdedS6eXsvJf3SYtECSJmEXRh KkgFzusmDzzcBKsGpafEGfCCP6qBftVgbtQ1LNM7IKtqSdK8de7aGjqir3M2DYaSIVR99njGcGltF +RRYF6lDJn2XigU8JdwZcbzJ8hpcS3CG3+RYvc0Qeze95YmFlTnoWoHYl6bnh6Isa8+upnYSuut0M nkaxKtFJaqTDyORCwSsAfVXK4M66IwiuIR3WICtWHYEYDVyJ1VVTbMei11dI3PF6pMdGFZhuIL1uJ k6Cl2PCg==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.100.1 #2 (Red Hat Linux)) id 1xMdTW-0000000AjgD-3dM8; Fri, 30 Oct 2026 03:40:18 +0000 Received: from sea.source.kernel.org ([172.234.252.31]) by bombadil.infradead.org with esmtps (Exim 4.100.1 #2 (Red Hat Linux)) id 1xMdTU-0000000Ajg2-2cAy for kexec@lists.infradead.org; Fri, 30 Oct 2026 03:40:16 +0000 Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) by sea.source.kernel.org (Postfix) with ESMTP id E7B03403F4; Fri, 30 Oct 2026 03:40:14 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 373651F000C1; Fri, 30 Oct 2026 03:40:12 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1793331614; bh=Bv38qew6Wsr0ojuGu26s7yan/OuyYioSrYN2sDRrsjM=; h=From:Subject:Reply-To:To:Cc:In-Reply-To:References:Date; b=I5GuMBeMlvP7xOF2reJ/9htIAgEgMSim3T/wHhP38g6j0ydv3kUTNlIBO3g+DSRfL A65PcwerGwEIRqfjP4owXvaRvPk13TylRHZrkEFOh4gyIwHwL2kFVoGYiCZeIR0Rcx kuz2Tg/JGT2tJ8yRYe/j5ZOmvXEw+PO+xDqH7MnJcz1fhjWCoId4r/tn2fJR0kXE/9 mYWcHrTtDsLFsEulgb649N9GhfERZNgqhOBJ+M1YjANmOPek1W/mBY0ul8CRfK4INi RHRSKIEgYa1OclNYrOv/SHkuCBTTF3DLO3yPrJOx8U6jfIU9wVgmTJLdYIbjIm7WOq CM/A3AjjzvJ1g== Message-ID: From: sashiko-bot@kernel.org Subject: Re: [PATCH v2 01/47] mm/mglru: don't use stack pointers when walking PUD and PMD tables 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" , "Muhammad Usama Anjum" In-Reply-To: <20261029-fixes_core-v2-1-a64ce7f83abb@kernel.org> References: <20261029-fixes_core-v2-0-a64ce7f83abb@kernel.org> <20261029-fixes_core-v2-1-a64ce7f83abb@kernel.org> Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable Date: Fri, 30 Oct 2026 03:40:11 +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=-10.9 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: > From: Josef Bacik >=20 > MGLRU passes stack copies of page-table entries in walk_pud_range() and > walk_pmd_range() when walking to the next level. These copies can become > stale when khugepaged or MADV_DONTNEED (CONFIG_PT_RECLAIM) removes a PTE > table concurrently. >=20 > This pattern dates back to commit bd74fdaea146 ("mm: multi-gen LRU: > support page table walks"). Likely, earlier locking masked the latent > bug. Later changes exposed it: commit 1d65b771bc08 ("mm/khugepaged: > retract_page_tables() without mmap or vma lock") allowed concurrent > retraction, and commit cf4a65539c13 ("memcg-v1: no need for memcg locking > for MGLRU") dropped the walker's outer RCU protection. >=20 > The fix is simple, so just fix the original commit so we don't have to > [ ... ] > Reviewed-by: Barry Song > Reviewed-by: Baolin Wang > Reviewed-by: Pedro Falcato > Reviewed-by: Kiryl Shutsemau (Meta) > 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/20261029-fixes_core= -v2-0-a64ce7f83abb@kernel.org?part=3D1