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 3F06D606A31A for ; Fri, 30 Oct 2026 03:42:36 +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=b4Hor+Lq; dkim=pass (2048-bit key, unprotected) header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=itx+Xv1t 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=tpeknwVNJmP/bKKG+fXm/2Q3N6ESvrFSEq0ZVqkxjXo=; b=b4Hor+LqSTATu3yVSck3PYitMY hqVbjxgbCVNrfpPIwhGBhaHCrH/hXQvbBjxWWBxJEFUufn7EniKV8bH6NvcgtRlUrZMkmERNOZnvO U5XmmnWlsC/Ybb7Drbxrc5VUZpwjmOxvJqE88wEuAdHa3ELmlmQmUgbSoy9Up0x/pCAF724Qmw1Fb 0EcdF8DmG5/xs/duKW1AjLDlY5zXE4poW1WkqjkiB7ygRsraygb/TDdNVc7n3ZP8nI5PLGrb8LBYq E5ABrx7SLJvSyo0JGnqfzZMWNQex9h/5dwf45QHMfah3haL6HgYbtyX8nHNVtl/QZS0qfZHTtfI7S fqZJUrtw==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.100.1 #2 (Red Hat Linux)) id 1xMdVj-0000000AlFt-3fep; Fri, 30 Oct 2026 03:42:35 +0000 Received: from sea.source.kernel.org ([2600:3c0a:e001:78e:0:1991:8:25]) by bombadil.infradead.org with esmtps (Exim 4.100.1 #2 (Red Hat Linux)) id 1xMdVi-0000000AlEJ-13AF for kexec@lists.infradead.org; Fri, 30 Oct 2026 03:42:34 +0000 Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) by sea.source.kernel.org (Postfix) with ESMTP id 026E640444; Fri, 30 Oct 2026 03:42:34 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id D35851F00A02; Fri, 30 Oct 2026 03:42:30 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1793331753; bh=tpeknwVNJmP/bKKG+fXm/2Q3N6ESvrFSEq0ZVqkxjXo=; h=From:Subject:Reply-To:To:Cc:In-Reply-To:References:Date; b=itx+Xv1tuOl2fS/x35e04kS2m3+RtcQGcYRf7iqwkM/rWJ9UsF7NqLdUzbGiFAUib dF5Ut7kniw77qXpLAD/xtefZwBopd1sTzFMt7kneV9JwdVrZYL3djKRegvXcFkB/Qz Pe19hqDgtWewUWdj3/7u9y/DYSS5j/ebdQrcwIQG04PcL78p1HWtFEqo1BirKJz2+B FCKNuf1ONrByNQAV0nFlatf1IK3j9OfEy/6xL9xC+A8KU8rYiCr8oENRKafhjLTtno Z1e+LAST9fDkMFW7fw6kQ5HqX5NS9ABi7fxmFIAk/clpV0Rs83EXW/MFzo49mXAlmL 6cHykGwT5hnGg== Message-ID: From: sashiko-bot@kernel.org Subject: Re: [PATCH v2 43/47] mm/huge_memory: split huge PUDs when adjusting VMA boundaries 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 In-Reply-To: <20261029-fixes_core-v2-43-a64ce7f83abb@kernel.org> References: <20261029-fixes_core-v2-0-a64ce7f83abb@kernel.org> <20261029-fixes_core-v2-43-a64ce7f83abb@kernel.org> Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable Date: Fri, 30 Oct 2026 03:42:30 +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: > PFN mappings such as VFIO PCI BAR mappings can use PUD leaves while > allowing VMA splits at page granularity. However, vma_adjust_trans_huge() > only handles PMDs. >=20 > After faulting a writable PUD-sized VFIO BAR mapping, changing its first > page to read-only with mprotect() makes the PMD walk treat the PUD leaf > as a PMD table. Applying MADV_DONTFORK to the first PMD-sized chunk leaves > the PUD spanning two VMAs: the PMD-aligned boundary skips splitting. >=20 > Walk the page tables once at each adjusted boundary and split a huge > PUD or PMD leaf as needed. Handle PUD leaves even when the boundary is > PMD-aligned. >=20 > Fixes: f9e54c3a2f5b7 ("vfio/pci: implement huge_fault support") > Cc: stable@vger.kernel.org > 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=3D43