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Howlett" , Nico Pache , Ryan Roberts , Dev Jain , Barry Song , Lyude Paul , Danilo Krummrich , David Airlie , Simona Vetter , Ralph Campbell , =?UTF-8?Q?Mika_Penttil=C3=A4?= , Matthew Brost , Francois Dugast References: <20250916122128.2098535-1-balbirs@nvidia.com> <20250916122128.2098535-5-balbirs@nvidia.com> <7987AB89-4E80-4A0D-8736-E95F998698DA@nvidia.com> <901c82e7-0442-4791-b249-b035f8ee428d@nvidia.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: hvXF72Np17B0EWCOjHvl2McgFD2bNscb9eA9LpEnQ0U_1758794782 X-Mimecast-Originator: redhat.com Content-Language: en-US Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit X-Stat-Signature: 7md7ijaq1g69oh68dqosb4a7zjg71cnx X-Rspam-User: X-Rspamd-Queue-Id: 1A68210000D X-Rspamd-Server: rspam04 X-HE-Tag: 1758794784-870092 X-HE-Meta: U2FsdGVkX1+GPgl46cNCXZzLnvNivfRb942UeEzaaDEfV70Z/FW5XNPxdluPL80R3CC5+sje86DbfruSX4b4c3D8lSdCR7x5KF0kfkA7ztJbFJfVvs1GY4nt3NJddoU/p0jjapmG7WxXmK5tXzQX1cBlIDykPh2TgeHghQ14hQAc5OWWWf2HIExrcL+tNB5cbaRaRzBAfF2OgzRYSQqnWSr8gttAnDOkyCKhpxzqlueJjBTuYtV6QI2i/WQ5UgLTsthtBec02bQtiT2iWARpleJpZ8WA7a8jk/xc9F1zW0JuJVoZjfh9frsfcjeCSYiwX/7Rq1YggNbflapwphxPh2BHfmS4QswYOKZ7eQZJiyc9PllQs3F3KXWuaUYHZsZSqEmp113pQPZhREqzJA+C/FfKvW7erPY5zwR7E5v9O06alcxN2Gehuu3g3o6H51HbVaKK1aRmh6dnNynrHfXIIUvyIFCGnvYSVBrRSMQ+TBBfnYrryTFt2X00hapW9cy0CKarKoJoTLAyZrOwnm9dE/9IhGcOjlLkt7Eq6XwoZKFhkSxoqU8iYlF/QWDzOpIzvIDyyTmG29TZXa+mzAU3kHz0FpVJN5i3YNrcTgSxbYuVMxUAqkPL9OJZvgeYLMJKd53NkB2Ofm34S27WuL8wbHi7yRAufzecVdyCfuNs01Z1bqNS9sTGGqdKIj5f4sHYfXJ3cKK9PwxWb5tFSRNpD0WV1JELgHQzyjj8WdMjbuaWDUBDTkzgBoryMavcVnUDiQxTWGO1IaJEjSu5pcGdh7OzIXlqo5vNMx1pJAX4sZz3rj6SXtkMpeY3sNLsK096H28QHBbxMguS3VCp7L0l+Wc9R73XQq3x6oBJ+oBsBa4musJdm8driCgEVnZnEY3XNF/dgf19Ban7rYYpBRZwKJ/pzLZU56l0R4ATLv6hL34jLg17MnjPV/R74uxgdiEyKYihqfFYc8GXMVIVlAY GX/2a6fN 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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: >>> Even if this is the only call site, there is no guarantee that >>> there will be none in the future. I am not sure why we want caller >>> to handle this special case. Who is going to tell the next user >>> of RMP_USE_SHARED_ZEROPAGE or caller to try_to_map_unused_to_zeropage() >>> that device private is incompatible with them? >>> >> >> I don't disagree, but the question was why are device private pages even making >> it to try_to_map_unused_to_zeropage()>> > > Then, it could be done in remove_migration_pte(): > > if (rmap_walk_arg->map_unused_to_zeropage && > !folio_is_device_private(folio) && > try_to_map_unused_to_zeropage(&pvmw, folio, idx)) > continue; > > Maybe I am too hung up on this and someone else could pat on my back and > tell me it is OK to just do this at the only caller instead. :) I think we shouldn't set a flag for a folio that does not make any sense. Just like we don't set the flag for non-anon folios? In addition, we could add a VM_WARN_ON_ONCE(folio_is_device_private(folio)) in try_to_map_unused_to_zeropage(), to catch any future abuse. -- Cheers David / dhildenb