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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) X-Mailing-List: linuxppc-dev@lists.ozlabs.org List-Id: List-Help: List-Owner: List-Post: List-Archive: , List-Subscribe: , , List-Unsubscribe: Precedence: list Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit 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?