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charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit X-Rspam-User: X-Rspamd-Server: rspam09 X-Rspamd-Queue-Id: 7DEBA40003 X-Stat-Signature: zjfyqorxcfdngpudomuzp155jjbybuog X-HE-Tag: 1750699519-766474 X-HE-Meta: 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 eS42RIsk yXJLRD4Ib1QHWUZxQe3aIWuhJNvMxyDw3RxvJIfhoPiUB2tdrkPk0yLaT+OEg+f8tYcWrKczfySHU+p84TZawlXw9pyXGTgAD7AcnE7xBQAc81hXHP0R+YvMNyWq/YM2Sms8gBQkHNabIGGuM9I4XkV9blsm98E7rZIJKqacxrxGpy2qpydCy/Hd4wJZEtNrX9ngm 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: >>> >>> How about an updated commit like this? >>> >>> Currently, most of the userfaultfd features are implemented directly in the >>> core mm. It will invoke VMA specific functions whenever necessary. So far >>> it is fine because it almost only interacts with shmem and hugetlbfs. >>> >>> This patch introduces a generic userfaultfd API for vm_operations_struct, >>> so that any type of file (including kernel modules that can be compiled >>> separately from the kernel core) can support userfaults without modifying >>> the core files. >> >> .... is it really "any file" ? I doubt it, but you likely have a better idea >> on how it all could just work with "any file". >> >>> >>> After this API applied, if a module wants to support userfaultfd, the >>> module should only need to touch its own file and properly define >>> vm_uffd_ops, instead of changing anything in core mm. >>> >>> ... >> >> Talking about files and modules is still confusing I'm afraid. It's really a >> special-purpose file (really, not any ordinary files on ordinary >> filesystems), no? > > One major reason I wanted to avoid the term "in-memory" is that we already > support most of the files on WP_ASYNC, so emphasizing on in-memory might be > misleading, even though WP_ASYNC isn't much taken into the picture of the > vm_uffd_ops being proposed. Oh, yes, agreed on WP_ASYNC. But they would not be using the vma_ops thingy, right? -- Cheers, David / dhildenb