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b=dUgjHgXCJ4vLfIuFrQEgzWR4UlIov1j6lq3IiUh6JykkYZoVRU4FVQ+eqKzEWh5JP bGhTuBV6JzJbZD3EjvcLgLbt0bqoT3GIfOiZwPcqVKjryOgz8ZWvBYHCUZGyH46jvf OHaWWaQzE1JxaRR+skY0/u9B3GBcNsWDTwe71wYLsulu3nOBOfQtuA/9M9RJahs96+ NFAos8uWErreYYeOHA8j4HPZ2s6teErhWiB8tB3nga6FegO5utJqYFN57oH5LdO4zo Em+16p83yNb+piA3yiqaSL7fPNO0DXlZ2SfnI+pnTKb5X3SUIKBv8vT7hvRXNbwVEp gs0KuoCw3FFGA== Message-ID: <01d7d54d-0047-4eb6-a1d2-5b3f113f26cf@kernel.org> Date: Tue, 27 Oct 2026 09:57:48 +0100 X-Archived-By: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH 0/6] mm: fix pfn walker races with memory offline To: "Gregory Price (Meta)" , linux-mm@kvack.org Cc: linux-kernel@vger.kernel.org, linux-cxl@vger.kernel.org, kernel-team@meta.com, akpm@linux-foundation.org, vbabka@kernel.org, surenb@google.com, mhocko@suse.com, brendan.jackman@linux.dev, hannes@cmpxchg.org, ziy@nvidia.com, linmiaohe@huawei.com, nao.horiguchi@gmail.com, ljs@kernel.org, liam@infradead.org, rppt@kernel.org, osalvador@suse.de, muchun.song@linux.dev, iamjoonsoo.kim@lge.com, anshuman.khandual@arm.com References: <20261027042204.3741307-1-gourry@gourry.net> From: "David Hildenbrand (Arm)" Content-Language: en-US Autocrypt: addr=david@kernel.org; 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charset=UTF-8 Content-Transfer-Encoding: 7bit X-Rspamd-Queue-Id: 5BF2C40004 X-Stat-Signature: giscsqudubu1wt68e63acuxru73m1sb5 X-Spam-Status: No, score=-7.6 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_PASS,SPF_PASS,USER_AGENT_SANE_1 autolearn=no autolearn_force=no version=4.0.1 X-Rspam-User: X-Rspamd-Server: rspam09 X-HE-Tag: 1793091477-829349 X-HE-Meta: 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 5wARvmXd PRULvssIEsiLN8Jw0vGZbEh6yEwlNcsZc9uKWPxYdWwZ3muzwhl+HS6zgye+vMklKLU3yJs82xWc+kAz9ym8HFzqCa6hm3wt6hSi437sNmFQWzLWdXsyOJ8YK3+dkozNxR+EWtDVxfbimqAib8Bmzg9QJRun6g1IG7OYI6RhQt7KThdHl28aUybVdtrRBcrthRAB0UiORhUBguhKO6P5ar+7FpbHnql4j59ETE1YuNUZl0D/1MHRnnGvWXso5oyv15yuzr9Z0NhxxQzpUAYlvZgQ+EwpfhJhZbj60qtz606k/8tW57aXE1h20njUkLTyrFQYPioRsUfcp4398Q5dH97qAVQ== Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: X-Spam-Checker-Version: SpamAssassin 4.0.1 (2024-03-26) on aws-us-west-2-korg-listserv-alma10-1 On 10/27/26 05:21, Gregory Price (Meta) wrote: > Several pfn walkers check that a struct page is online, then use it > after memory offline has poisoned it (CONFIG_DEBUG_VM) or removal has > freed the vmemmap. Five of the races crash the kernel; the sixth leaves > an offline spinning with the device hotplug lock held. I have roughly the exact same list of AI garbage fixes here from a certain company. And I consider this all extremely low priority. So this is something to discuss throughout the next months and do it properly. -- Cheers, David