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[2003:d8:2f23:c700:d8ae:41bf:492a:9e4c]) by smtp.gmail.com with ESMTPSA id 5b1f17b1804b1-45a1c773e57sm88724495e9.23.2025.08.15.23.31.59 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Fri, 15 Aug 2025 23:31:59 -0700 (PDT) Message-ID: <15ccbbb0-8ebc-4c50-a1c8-fbe5416ecf46@redhat.com> Date: Sat, 16 Aug 2025 08:31:59 +0200 MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH 2/3] mm/rmap: could be partially_mapped only after no entire map To: Lorenzo Stoakes , Wei Yang Cc: akpm@linux-foundation.org, riel@surriel.com, Liam.Howlett@oracle.com, vbabka@suse.cz, harry.yoo@oracle.com, linux-mm@kvack.org References: <20250815084943.23063-1-richard.weiyang@gmail.com> <20250815084943.23063-3-richard.weiyang@gmail.com> <458c4ea9-1e33-4159-a545-6ad2c5b81add@lucifer.local> 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: <458c4ea9-1e33-4159-a545-6ad2c5b81add@lucifer.local> X-Mimecast-Spam-Score: 0 X-Mimecast-MFC-PROC-ID: YPMEhSlOY5ldnVPRdp02Z_H-XRnheFfLvGuYBOOAdzA_1755325921 X-Mimecast-Originator: redhat.com Content-Language: en-US Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit X-Rspamd-Server: rspam10 X-Rspamd-Queue-Id: 4DA111C0007 X-Stat-Signature: okuqr3ebgmq9ekqipn4wzkecy7f3ai7a X-Rspam-User: X-HE-Tag: 1755325925-593081 X-HE-Meta: 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 iyKcW8Nn 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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 15.08.25 12:08, Lorenzo Stoakes wrote: > On Fri, Aug 15, 2025 at 08:49:42AM +0000, Wei Yang wrote: >> If it is not the last entire map, we are sure the folio is not partially >> mapped. >> >> Move the check when there is no entire map. >> > > This one I don't like, you're having to sit and think about why it is that > this would be the case, vs. just unconditionally doing it. > > Again, as mentioned on previous series, just because we could do something > doesn't mean we should, unless there's statistically reliable perf data on > something real-world indicating we _must_, code clarity absolutely beats > everything else on importance. > > So yeah, sorry but no to this patch, please resend with just the two > reviewed (unless David radically disagrees with me :) The compiler can figure out that "nr == 0" if the "if (last)" branch is not taken. So I tend to prefer keeping it as is. -- Cheers David / dhildenb