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Shutemov" , linux-mm@kvack.org, linux-kernel@vger.kernel.org, Andrew Morton , Jens Axboe , Matthew Wilcox , Dennis Dalessandro , Leon Romanovsky , Christian Benvenuti , Nelson Escobar , Bernard Metzler , Peter Zijlstra , Ingo Molnar , Arnaldo Carvalho de Melo , Mark Rutland , Alexander Shishkin , Jiri Olsa , Namhyung Kim , Ian Rogers , Adrian Hunter , Bjorn Topel , Magnus Karlsson , Maciej Fijalkowski , Jonathan Lemon , "David S . Miller" , Eric Dumazet , Jakub Kicinski , Paolo Abeni , Christian Brauner , Richard Cochran , Alexei Starovoitov , Daniel Borkmann , Jesper Dangaard Brouer , John Fastabend , linux-fsdevel@vger.kernel.org, linux-perf-users@vger.kernel.org, netdev@vger.kernel.org, bpf@vger.kernel.org, Oleg Nesterov , John Hubbard , Pavel Begunkov , Mika Penttila , David Hildenbrand , Dave Chinner , Theodore Ts'o , Peter Xu , Matthew Rosato , "Paul E . McKenney" , Christian Borntraeger Subject: Re: [PATCH v9 0/3] mm/gup: disallow GUP writing to file-backed mappings by default Message-ID: References: <20230515110315.uqifqgqkzcrrrubv@box.shutemov.name> <7f6dbe36-88f2-468e-83c1-c97e666d8317@lucifer.local> <20230517072920.bfs7gfo4whdmi6ay@quack3> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: X-SRS-Rewrite: SMTP reverse-path rewritten from by bombadil.infradead.org. See http://www.infradead.org/rpr.html X-Stat-Signature: bouka163574arspthf7mjwc3chmjjky3 X-Rspamd-Server: rspam05 X-Rspamd-Queue-Id: E279A180012 X-Rspam-User: X-HE-Tag: 1684309419-593528 X-HE-Meta: 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 pIhwuBvg pXc8G6enABmjMHX1s7h4oBW5JIzOuAtgdTw2Lk4bT7749JuGq9amDRkU7iJXTG0znqNUE+MnXLG5wodSObTX+Op38d+RgdZpYUvIrlh2nCgenMgXk8UYKVqYTtZKOyXmT788b2JHyOTKxHBX8GBwRWOmOu3V/IXk8z21wATMshDUIj/faZBladLXpYYIFn6l0lx+onlszBA7Yb9PjeZFYRkykaObCCmV34ojqWgTbEi0PygQOkJ70BlrCNRWvaQIhVm2TJ2o6GkSt/M80rzhuX0Mfr80bbmNz6gBuoIMc8cSaR27y7kV10xKxueHRqWqjhVdfNnFyDVvw0ii+p/ZpJw8flq+UazGrEGgcJRv733ecYI4sSAPJNU9UDAAOLrsCUGsQKtnvFVilDUQSqLW9b4R/Td0xbk3ERfKdolldoLUHmMlmFO/yPuT9N3w2hFxVHsG0wU9WBKSj4RI= 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: On Wed, May 17, 2023 at 08:40:26AM +0100, Lorenzo Stoakes wrote: > > I'm not sure what you mean by "total flexibility" here. In my opinion it is > > also about how HW performs checksumming etc. > > I mean to say *_ops allow a lot of flexibility in how things are > handled. Certainly checksumming is a great example but in theory an > arbitrary filesystem could be doing, well, anything and always assuming > that only userland mappings should be modifying the underlying data. File systems need a wait to track when a page is dirtied so that it can be written back. Not much to do with flexbility.