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 DB2DC606A31A for ; Tue, 27 Oct 2026 00:12:53 +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=hxqN4M6Z; dkim=pass (2048-bit key, unprotected) header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=jKfK0sgy 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=/2z2A5flMiKJNvY0JwIpCH3aK/To9m90m+ZoMVFJAbY=; b=hxqN4M6ZpslFiTMQIYdyv4UJaQ mQ+HADRtX+CIunm5rWu77yAgd3w/jJ/8XZ4kUZuItM0onMsjm8eQqpED23nrqo82ai2+Y43AcG481 /0fj2Iav0IxqcPBqITvVw2wFXT/DJZ9sbwQ7OnTL7vaKHBCW3gl8TzBovElF7SF+87O+JkVOAMFcY m186lMOiYFh5yOM9NjtEYZzRTHAcsOYxWSF9WbzySZHx7BESjbg18GnDUmjnszTc8z3ThL5C/eOtp rWJtoMKFdfJTqzx+gDn1ejG14tKP28D5A3fkMoBx5fddwo2Kt6vcF2fBwhdjfzm157mXs6MTj/9y8 Og3IRDLQ==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.100.1 #2 (Red Hat Linux)) id 1xLUo9-00000003V8X-2Tx1; Tue, 27 Oct 2026 00:12:53 +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 1xLUo8-00000003V7X-1ism for kexec@lists.infradead.org; Tue, 27 Oct 2026 00:12:53 +0000 Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) by tor.source.kernel.org (Postfix) with ESMTP id BB73A600CB; Tue, 27 Oct 2026 00:12:51 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id B730D1F01825; Tue, 27 Oct 2026 00:12:48 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1793059971; bh=/2z2A5flMiKJNvY0JwIpCH3aK/To9m90m+ZoMVFJAbY=; h=From:Subject:Reply-To:To:Cc:In-Reply-To:References:Date; b=jKfK0sgy7sDw/r65SnJhorz2KfEoW49+tV57Muebo4YrwayT7a80Lv0kcp6Wiz9XF X4fqpPLrLxOaA7aZ/zH+HWb8FpNBDYfG8wvquOoLrbWRcu1HaUYpX19q+6t7oAlUKL OAbpcjH6BdfM2C83MvaiISTStNB06nOyjt0O0x2MRgQoaM4k+lqJG/T3TkZNdpzzsL eLqqeHje6DRTan93idtttSxY3xuyaGUTCb5dLp4V5I6lWqOt/yrlYiFF+CWgHUxvUt VXNz1eLLm0MvtNOYsiBxeJJVjeJKEBIAKkpLN1yFzkza2N45DemAPynkC/suP7l0Y0 zZhnRn6N07Jrw== Message-ID: From: sashiko-bot@kernel.org Subject: Re: [PATCH 15/46] mm/khugepaged: always recheck the pmd in try_collapse_pte_mapped_thp() 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-v1-15-6f74bec9a5bb@kernel.org> References: <20261027-fixes_core-v1-0-6f74bec9a5bb@kernel.org> <20261027-fixes_core-v1-15-6f74bec9a5bb@kernel.org> Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable Date: Tue, 27 Oct 2026 00:12:48 +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: > From: Josef Bacik >=20 > 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. >=20 > 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. >=20 > Fix it by performing the check unconditionally. >=20 > Fix generated by an LLM and sent by Josef Bacik in private. >=20 > 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 ] > 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=3D15