From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 56A60D3CC82 for ; Wed, 14 Jan 2026 21:48:31 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id F3C4D10E698; Wed, 14 Jan 2026 21:48:30 +0000 (UTC) Authentication-Results: gabe.freedesktop.org; dkim=pass (1024-bit key; unprotected) header.d=linux-foundation.org header.i=@linux-foundation.org header.b="P6vtWoYC"; dkim-atps=neutral Received: from tor.source.kernel.org (tor.source.kernel.org [172.105.4.254]) by gabe.freedesktop.org (Postfix) with ESMTPS id 695FE10E695; Wed, 14 Jan 2026 21:48:28 +0000 (UTC) Received: from smtp.kernel.org (transwarp.subspace.kernel.org [100.75.92.58]) by tor.source.kernel.org (Postfix) with ESMTP id 105006001D; Wed, 14 Jan 2026 21:48:27 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 94455C4CEF7; Wed, 14 Jan 2026 21:48:25 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linux-foundation.org; s=korg; t=1768427306; bh=sVjE+SfQsdIUMHLLdK2WZZMe9meeOIqp+vLdzF39rao=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=P6vtWoYCIlr2XYuGHN8Ct1JWv57QVflPPPZ09aqbdSf6sWvv6Psm4BbFl9dEKxvME 9IiuEcpRE83qTyXp72NniYCaihdkRtUtnm5MV6es8ZMUNP2zri1F+QO+WeYttAzUaW ul+FCK9Uuub6AWdHHLL0xvAdQEb3R2ZlrFvcN/18= Date: Wed, 14 Jan 2026 13:48:25 -0800 From: Andrew Morton To: Francois Dugast Cc: intel-xe@lists.freedesktop.org, dri-devel@lists.freedesktop.org, Matthew Brost , Zi Yan , Alistair Popple , adhavan Srinivasan , Nicholas Piggin , Michael Ellerman , "Christophe Leroy (CS GROUP)" , Felix Kuehling , Alex Deucher , Christian =?UTF-8?B?S8O2bmln?= , David Airlie , Simona Vetter , Maarten Lankhorst , Maxime Ripard , Thomas Zimmermann , Lyude Paul , Danilo Krummrich , David Hildenbrand , Oscar Salvador , Jason Gunthorpe , Leon Romanovsky , Lorenzo Stoakes , "Liam R . Howlett" , Vlastimil Babka , Mike Rapoport , Suren Baghdasaryan , Michal Hocko , Balbir Singh , linuxppc-dev@lists.ozlabs.org, kvm@vger.kernel.org, linux-kernel@vger.kernel.org, amd-gfx@lists.freedesktop.org, nouveau@lists.freedesktop.org, linux-mm@kvack.org, linux-cxl@vger.kernel.org Subject: Re: [PATCH v5 1/5] mm/zone_device: Reinitialize large zone device private folios Message-Id: <20260114134825.8bf1cb3e897c8e41c73dc8ae@linux-foundation.org> In-Reply-To: <20260114192111.1267147-2-francois.dugast@intel.com> References: <20260114192111.1267147-1-francois.dugast@intel.com> <20260114192111.1267147-2-francois.dugast@intel.com> X-Mailer: Sylpheed 3.7.0 (GTK+ 2.24.33; x86_64-pc-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit X-BeenThere: intel-xe@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Intel Xe graphics driver List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: intel-xe-bounces@lists.freedesktop.org Sender: "Intel-xe" On Wed, 14 Jan 2026 20:19:52 +0100 Francois Dugast wrote: > Reinitialize metadata for large zone device private folios in > zone_device_page_init prior to creating a higher-order zone device > private folio. This step is necessary when the folio’s order changes > dynamically between zone_device_page_init calls to avoid building a > corrupt folio. As part of the metadata reinitialization, the dev_pagemap > must be passed in from the caller because the pgmap stored in the folio > page may have been overwritten with a compound head. Thanks. What are the worst-case userspace-visible effects of the bug?