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To: Gregory Price Cc: Zi Yan , linux-mm@kvack.org, linux-kernel@vger.kernel.org, kernel-team@meta.com, akpm@linux-foundation.org, vbabka@suse.cz, surenb@google.com, mhocko@suse.com, jackmanb@google.com, hannes@cmpxchg.org References: <20251020170615.1000819-1-gourry@gourry.net> <487730c6-423a-4a03-a668-9b9ff92a5cfb@redhat.com> <609E7E01-33A6-4931-AC89-1F4B2944FB64@nvidia.com> <272c425a-b191-4eef-af6e-2bca1db7a940@redhat.com> <0d92a675-ab24-4b1c-be71-956f09a9e973@redhat.com> <451b72a3-8052-4dfb-84e7-1e97c3388db0@redhat.com> From: David Hildenbrand Autocrypt: addr=david@redhat.com; keydata= xsFNBFXLn5EBEAC+zYvAFJxCBY9Tr1xZgcESmxVNI/0ffzE/ZQOiHJl6mGkmA1R7/uUpiCjJ dBrn+lhhOYjjNefFQou6478faXE6o2AhmebqT4KiQoUQFV4R7y1KMEKoSyy8hQaK1umALTdL QZLQMzNE74ap+GDK0wnacPQFpcG1AE9RMq3aeErY5tujekBS32jfC/7AnH7I0v1v1TbbK3Gp XNeiN4QroO+5qaSr0ID2sz5jtBLRb15RMre27E1ImpaIv2Jw8NJgW0k/D1RyKCwaTsgRdwuK Kx/Y91XuSBdz0uOyU/S8kM1+ag0wvsGlpBVxRR/xw/E8M7TEwuCZQArqqTCmkG6HGcXFT0V9 PXFNNgV5jXMQRwU0O/ztJIQqsE5LsUomE//bLwzj9IVsaQpKDqW6TAPjcdBDPLHvriq7kGjt WhVhdl0qEYB8lkBEU7V2Yb+SYhmhpDrti9Fq1EsmhiHSkxJcGREoMK/63r9WLZYI3+4W2rAc UucZa4OT27U5ZISjNg3Ev0rxU5UH2/pT4wJCfxwocmqaRr6UYmrtZmND89X0KigoFD/XSeVv jwBRNjPAubK9/k5NoRrYqztM9W6sJqrH8+UWZ1Idd/DdmogJh0gNC0+N42Za9yBRURfIdKSb B3JfpUqcWwE7vUaYrHG1nw54pLUoPG6sAA7Mehl3nd4pZUALHwARAQABzSREYXZpZCBIaWxk ZW5icmFuZCA8ZGF2aWRAcmVkaGF0LmNvbT7CwZoEEwEIAEQCGwMCF4ACGQEFCwkIBwICIgIG FQoJCAsCBBYCAwECHgcWIQQb2cqtc1xMOkYN/MpN3hD3AP+DWgUCaJzangUJJlgIpAAKCRBN 3hD3AP+DWhAxD/9wcL0A+2rtaAmutaKTfxhTP0b4AAp1r/eLxjrbfbCCmh4pqzBhmSX/4z11 opn2KqcOsueRF1t2ENLOWzQu3Roiny2HOU7DajqB4dm1BVMaXQya5ae2ghzlJN9SIoopTWlR 0Af3hPj5E2PYvQhlcqeoehKlBo9rROJv/rjmr2x0yOM8qeTroH/ZzNlCtJ56AsE6Tvl+r7cW 3x7/Jq5WvWeudKrhFh7/yQ7eRvHCjd9bBrZTlgAfiHmX9AnCCPRPpNGNedV9Yty2Jnxhfmbv Pw37LA/jef8zlCDyUh2KCU1xVEOWqg15o1RtTyGV1nXV2O/mfuQJud5vIgzBvHhypc3p6VZJ lEf8YmT+Ol5P7SfCs5/uGdWUYQEMqOlg6w9R4Pe8d+mk8KGvfE9/zTwGg0nRgKqlQXrWRERv cuEwQbridlPAoQHrFWtwpgYMXx2TaZ3sihcIPo9uU5eBs0rf4mOERY75SK+Ekayv2ucTfjxr Kf014py2aoRJHuvy85ee/zIyLmve5hngZTTe3Wg3TInT9UTFzTPhItam6dZ1xqdTGHZYGU0O otRHcwLGt470grdiob6PfVTXoHlBvkWRadMhSuG4RORCDpq89vu5QralFNIf3EysNohoFy2A LYg2/D53xbU/aa4DDzBb5b1Rkg/udO1gZocVQWrDh6I2K3+cCs7BTQRVy5+RARAA59fefSDR 9nMGCb9LbMX+TFAoIQo/wgP5XPyzLYakO+94GrgfZjfhdaxPXMsl2+o8jhp/hlIzG56taNdt VZtPp3ih1AgbR8rHgXw1xwOpuAd5lE1qNd54ndHuADO9a9A0vPimIes78Hi1/yy+ZEEvRkHk /kDa6F3AtTc1m4rbbOk2fiKzzsE9YXweFjQvl9p+AMw6qd/iC4lUk9g0+FQXNdRs+o4o6Qvy iOQJfGQ4UcBuOy1IrkJrd8qq5jet1fcM2j4QvsW8CLDWZS1L7kZ5gT5EycMKxUWb8LuRjxzZ 3QY1aQH2kkzn6acigU3HLtgFyV1gBNV44ehjgvJpRY2cC8VhanTx0dZ9mj1YKIky5N+C0f21 zvntBqcxV0+3p8MrxRRcgEtDZNav+xAoT3G0W4SahAaUTWXpsZoOecwtxi74CyneQNPTDjNg azHmvpdBVEfj7k3p4dmJp5i0U66Onmf6mMFpArvBRSMOKU9DlAzMi4IvhiNWjKVaIE2Se9BY FdKVAJaZq85P2y20ZBd08ILnKcj7XKZkLU5FkoA0udEBvQ0f9QLNyyy3DZMCQWcwRuj1m73D sq8DEFBdZ5eEkj1dCyx+t/ga6x2rHyc8Sl86oK1tvAkwBNsfKou3v+jP/l14a7DGBvrmlYjO 59o3t6inu6H7pt7OL6u6BQj7DoMAEQEAAcLBfAQYAQgAJgIbDBYhBBvZyq1zXEw6Rg38yk3e EPcA/4NaBQJonNqrBQkmWAihAAoJEE3eEPcA/4NaKtMQALAJ8PzprBEXbXcEXwDKQu+P/vts IfUb1UNMfMV76BicGa5NCZnJNQASDP/+bFg6O3gx5NbhHHPeaWz/VxlOmYHokHodOvtL0WCC 8A5PEP8tOk6029Z+J+xUcMrJClNVFpzVvOpb1lCbhjwAV465Hy+NUSbbUiRxdzNQtLtgZzOV Zw7jxUCs4UUZLQTCuBpFgb15bBxYZ/BL9MbzxPxvfUQIPbnzQMcqtpUs21CMK2PdfCh5c4gS sDci6D5/ZIBw94UQWmGpM/O1ilGXde2ZzzGYl64glmccD8e87OnEgKnH3FbnJnT4iJchtSvx yJNi1+t0+qDti4m88+/9IuPqCKb6Stl+s2dnLtJNrjXBGJtsQG/sRpqsJz5x1/2nPJSRMsx9 5YfqbdrJSOFXDzZ8/r82HgQEtUvlSXNaXCa95ez0UkOG7+bDm2b3s0XahBQeLVCH0mw3RAQg r7xDAYKIrAwfHHmMTnBQDPJwVqxJjVNr7yBic4yfzVWGCGNE4DnOW0vcIeoyhy9vnIa3w1uZ 3iyY2Nsd7JxfKu1PRhCGwXzRw5TlfEsoRI7V9A8isUCoqE2Dzh3FvYHVeX4Us+bRL/oqareJ CIFqgYMyvHj7Q06kTKmauOe4Nf0l0qEkIuIzfoLJ3qr5UyXc2hLtWyT9Ir+lYlX9efqh7mOY qIws/H2t In-Reply-To: X-Mimecast-Spam-Score: 0 X-Mimecast-MFC-PROC-ID: q2nWTo8qXRdSH06_2C1Bcj5alBKattYmkbyYlyuiiyM_1760992710 X-Mimecast-Originator: redhat.com Content-Language: en-US Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit X-Rspamd-Queue-Id: F06F910000A X-Rspamd-Server: rspam11 X-Rspam-User: X-Stat-Signature: ujtxqw3p6eztrs8mz7cdsqwcp6gpggcs X-HE-Tag: 1760992720-115307 X-HE-Meta: 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 SiBWuFDX 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 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: On 20.10.25 22:27, Gregory Price wrote: > On Mon, Oct 20, 2025 at 10:17:42PM +0200, David Hildenbrand wrote: >> Yes, it's completely racy. >> >> I was primarily concerned about us calling functions that will VM_WARN_ON() >> etc due to the races; not that they would make us accept/jump over a range >> although we shouldn't. >> >> Of course, regarding the latter, we want to try as good as possible to avoid >> jumping over ranges that we can actually handle. >> > > I'll go ahead and add a snapshot_page. I'd say it's probably good enough initially to just use compound_head() and filter out crazy values. -- Cheers David / dhildenb