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b=ZMOmRJmj9cyIvK+9/Z6Utxfj3hYMxhgiKW5lnB/Rdh4KtUiA3CE+K+wGkmWs5DQdt 4NLrCuli2efs6PS4Z0oCoKWNjitS1zAGNCZgSYv4cboPA9pClWp9qWcbHHL3/s53vN CWVD0N8ojscvM9iXUbVpaFyL+gWZt+xXxZkD6of7jBRqDbIZNeYHbsk7Yo/BjlfUYL MFLL1KsQ1XPaQajU0jgv6HBqcWsmpCYkV3wc6JTgsmCx3yfycOSS4HynN/n/dTdwtM fAF5ACkJYtWCxQrZLPD6hlYp0+0i9OXkn36KCbajewnQupKzwEfLYXjzQ6iRAQTt1S pIM7+EaBAoUrg== Message-ID: <3192eca4-1c90-44ed-8386-bf635db357c4@kernel.org> Date: Fri, 6 Feb 2026 19:09:56 +0100 MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: ksm: initialize rmap values directly and make them const From: "David Hildenbrand (Arm)" To: Matthew Wilcox , xu.xin16@zte.com.cn Cc: akpm@linux-foundation.org, chengming.zhou@linux.dev, hughd@google.com, wang.yaxin@zte.com.cn, yang.yang29@zte.com.cn, linux-mm@kvack.org, linux-kernel@vger.kernel.org References: <202602061522548871ohgXN8z0qq87sTSX-yZc@zte.com.cn> <5a1cf097-5ab4-41d1-a707-a709de6210cf@kernel.org> Content-Language: en-US Autocrypt: addr=david@kernel.org; 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 B3JfpUqcWwE7vUaYrHG1nw54pLUoPG6sAA7Mehl3nd4pZUALHwARAQABzS5EYXZpZCBIaWxk ZW5icmFuZCAoQ3VycmVudCkgPGRhdmlkQGtlcm5lbC5vcmc+wsGQBBMBCAA6AhsDBQkmWAik AgsJBBUKCQgCFgICHgUCF4AWIQQb2cqtc1xMOkYN/MpN3hD3AP+DWgUCaYJt/AIZAQAKCRBN 3hD3AP+DWriiD/9BLGEKG+N8L2AXhikJg6YmXom9ytRwPqDgpHpVg2xdhopoWdMRXjzOrIKD g4LSnFaKneQD0hZhoArEeamG5tyo32xoRsPwkbpIzL0OKSZ8G6mVbFGpjmyDLQCAxteXCLXz ZI0VbsuJKelYnKcXWOIndOrNRvE5eoOfTt2XfBnAapxMYY2IsV+qaUXlO63GgfIOg8RBaj7x 3NxkI3rV0SHhI4GU9K6jCvGghxeS1QX6L/XI9mfAYaIwGy5B68kF26piAVYv/QZDEVIpo3t7 /fjSpxKT8plJH6rhhR0epy8dWRHk3qT5tk2P85twasdloWtkMZ7FsCJRKWscm1BLpsDn6EQ4 jeMHECiY9kGKKi8dQpv3FRyo2QApZ49NNDbwcR0ZndK0XFo15iH708H5Qja/8TuXCwnPWAcJ DQoNIDFyaxe26Rx3ZwUkRALa3iPcVjE0//TrQ4KnFf+lMBSrS33xDDBfevW9+Dk6IISmDH1R HFq2jpkN+FX/PE8eVhV68B2DsAPZ5rUwyCKUXPTJ/irrCCmAAb5Jpv11S7hUSpqtM/6oVESC 3z/7CzrVtRODzLtNgV4r5EI+wAv/3PgJLlMwgJM90Fb3CB2IgbxhjvmB1WNdvXACVydx55V7 LPPKodSTF29rlnQAf9HLgCphuuSrrPn5VQDaYZl4N/7zc2wcWM7BTQRVy5+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: <5a1cf097-5ab4-41d1-a707-a709de6210cf@kernel.org> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit X-Rspamd-Queue-Id: 9BC341C0010 X-Rspam-User: X-Rspamd-Server: rspam05 X-Stat-Signature: 3u7t5jdieh4d18m9qb88w3ckbq44aqdn X-HE-Tag: 1770401402-269394 X-HE-Meta: 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 LcMvW2n0 29FPhiYDihWYm+MszoIWL7h+xEATpqonKMZA9ifkp1vvss+Om273iuPZYYPMFopQ2IxhBP0VXLJro1F3OKy8ng1AoU2/a6b9F5ybPTmLmQajcTjNZpoqjTT4lJb0KOigZczy7Pn0nFJufIkX0yQ9Ngro8JbMuREuRi/bt0YlK+aS3mej18JblfKzkKxSry33LL/UoMWx54upyvwUwdSK4LmrgEEwW1e2DtDVPBC40TYODp9810VSvADuUGbqBlJMkOh3obzGapd/m/AB+hvsGFtziPKNoRMatxl9V1G81jgtSTJijfjUZlF3u5mNHyjOGN9pulCvLpLNUbIQQRpLKhFbP5A== 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 2/6/26 18:34, David Hildenbrand (Arm) wrote: > On 2/6/26 16:29, Matthew Wilcox wrote: >> On Fri, Feb 06, 2026 at 03:22:54PM +0800, xu.xin16@zte.com.cn wrote: >>> make them const to make code more robust. Besides, since KSM folios >>> are always >>> order-0, so folio_nr_pages(KSM folio) is always 1, so the line: >>> >>>     "pgoff_end = pgoff_start + folio_nr_pages(folio) - 1;" >>> >>> becomes directly: >>> >>>     "pgoff_end = pgoff_start;" >> >> How do you know KSM folios will always be order 0?  I don't.  NAK this >> change. > > Once that changes we can revisit. ACK from me stands. And just to elaborate a bit: I don't see support for > 0 happening any time soon, and it will require significant changes that I am not even sure we would want to maintain upstream :) -- Cheers, David