From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.remote-ip=100.103.45.18 ARC-Seal: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=none; t=1794510764; b=cEUIECiSI6KVyQFJ3CiOv01/UvPSM5o8uk7FlJsZIWI7MVCvvVdDTFl4hZ8283Af9uWl mv0npYJofMuelCDfhgY01DMz3g+BuuTPdIpjGD3ThEPhF5YCJMaCgrpJ4SiGZ2rtx6u9I Eq5Tmaktl38VZYCoN3FoDgVEfP9MC+Cfh1H2GJBIHlv4jhxqQ+ps/iGeXX3OG5CkgfxvX lQNtkX9n1ydLXVh++Cw6bA/vDboY73/e1YmsBgaH7zvfkFPDFijA5eI04PZT6YIYs4dj1 iOcfENkwGHEHF3e73EWOSgNSF/ON8oVqquhRdKiG2ZDahQop5qO92yKsIE/AFYxU5JQ== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1794510764; h=Received:DKIM-Signature:Date:From:To:Cc:Subject:Message-ID: References:MIME-Version:Content-Type:Content-Disposition:In-Reply-To; bh=7j0/jh5K7WkVjbCX+ro6AcPTgGQkDu7OOgaa2OHvFf0=; b=LHY4uTA3LeWOuIsXfstwoK8TjqGCz5i/8XYtT3+mUqD31M3qY3Br+pD4ByH3pj3xIvYf OeJd+GmvG4P3OyRYLUSrshdGs/V44wdteXN3n2PO0nVV2VFNRgow3qsXImpsLhMJ+mcGT l+/Fqo2f8QR2XKGVNfFUgHB7ew5wvm7BCgYVeuMpoFV2W5gT08ZqEia8AtlvjjHCs9tY7 DTGjp6wbiMaZ9IDSG2d0EsG8cQtEEy55oli4vBT25e8Gl76GsKnYoc4iq6Phb9cQRoopF AqmfajuHpUdEAOdUqdUEJMQnSX2GHBQFBh57io57HByD3s/H9owWSE3c4L1UDyRbCgA== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=X2DcnQfi; arc=none smtp.remote-ip=100.103.45.18 Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (prime256v1)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 7D85F606A8A8; Thu, 12 Nov 2026 19:12:44 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=X2DcnQfi Received: by smtp.kernel.org (Postfix) with ESMTPSA id 35DA01F000C7; Thu, 12 Nov 2026 19:12:35 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1794510764; bh=7j0/jh5K7WkVjbCX+ro6AcPTgGQkDu7OOgaa2OHvFf0=; h=Date:From:To:Cc:Subject:References:In-Reply-To; b=X2DcnQfispasGV6jq7eKqrWXQYe9QdoB0WVIKnVBn+qVUXoDQaMa2JP35NqG0rUDZ Yrmii1CSQ2kC+kVMFrVPqXYqjbzLC+HPEtZK2S2L8c6rNB2GFxYyNJPZ5sRzmWjMFu +dIYoXUFT/gQ+opKnKXgubaf3HqIYUBd2dghgWCQthT19T/pjLsHIlhSv2PdGSxZ72 Y6caRTdN4ASxjDMe8nlGd346MADQ4oacttKHM+fIxsG0Y7JqOVkTW9E8QoISZYwDzA cnXP1rnM8wHxMGKeIsrR63rxWcT49L3AMLJO5Cgb7ay9St5N9w6vYoCxGoRx1+yipR fXEha8CbDyJjw== Date: Thu, 12 Nov 2026 19:12:32 +0000 From: "Lorenzo Stoakes (ARM)" To: "Gregory Price (Meta)" Cc: David Hildenbrand , "Liam R. Howlett" , Vlastimil Babka , Mike Rapoport , Suren Baghdasaryan , Michal Hocko , David Rientjes , Shakeel Butt , Andrew Morton , Jann Horn , Pedro Falcato , "Matthew Wilcox (Oracle)" , Jan Kara , Nhat Pham , Johannes Weiner , Zi Yan , Matthew Brost , Joshua Hahn , Byungchul Park , Ying Huang , Alistair Popple , Usama Arif , Kairui Song , Balbir Singh , =?utf-8?B?SsOpcsO0bWU=?= Glisse , Kiryl Shutsemau , Yu-cheng Yu , Dave Hansen , Dennis Zhou , Tejun Heo , Christoph Lameter , Peng Fan , Josef Bacik , Chris Mason , linux-mm@kvack.org, linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org, "Borislav Petkov (AMD)" , Mark Brown , "Dennis Zhou (Facebook)" , Rick Edgecombe , Josef Bacik , stable@vger.kernel.org Subject: Re: [PATCH 07/13] mm/migrate_device: look up fault folio after a split Message-ID: References: <20261111-mason-migrate-et-al-fixes-v1-0-3d2454362e8d@kernel.org> <20261111-mason-migrate-et-al-fixes-v1-7-3d2454362e8d@kernel.org> <179450492332.482102.8905567682196853763.b4-reply@b4> X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <179450492332.482102.8905567682196853763.b4-reply@b4> On Thu, Nov 12, 2026 at 12:35:23PM -0500, Gregory Price (Meta) wrote: > On 2026-11-11 18:13 +0000, Lorenzo Stoakes (ARM) wrote: > > From: Josef Bacik > > > > migrate_vma_collect_pmd() looks up the folio of migrate->fault_page once, > > when it is entered, at which point the folio is locked. > > > > The fault folio is assumed not to change after this, however if > > migrate_vma_split_folio() splits a PTE-mapped large folio which contains > > the fault page, the fault page ends up in a different folio. > > > > Resolve the issue by looking up fault_folio again after each restart of the > > walk. > > > > Fixes: 022a12deda53 ("mm/migrate_device: handle partially mapped folios during collection") > > Cc: > > Signed-off-by: Josef Bacik > > [ ljs: pared down commit message ] > > Signed-off-by: Lorenzo Stoakes (ARM) > > Was able to reproduce this, and i think this also reveals (and fixes) > another bug in Nouveau (memory leak). I think the Nouveau driver still > needs a patch, but this otherwise looks correct. I think there was also another in the series that touched nouveau actually also... worrysome :) > > Tested-by: Gregory Price (Meta) Thanks! :) -- Cheers, Lorenzo