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([2a01:4b00:bd21:4f00:7cc6:d3ca:494:116c]) by smtp.gmail.com with ESMTPSA id 5b1f17b1804b1-47725bd740dsm303775e9.0.2025.10.29.07.01.49 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Wed, 29 Oct 2025 07:01:50 -0700 (PDT) Message-ID: <455fe1cb-bff1-4716-add7-cc4edecc98d2@gmail.com> Date: Wed, 29 Oct 2025 14:01:46 +0000 Precedence: bulk X-Mailing-List: io-uring@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v2 1/8] io_uring/uring_cmd: add io_uring_cmd_import_fixed_full() To: Joanne Koong , miklos@szeredi.hu, axboe@kernel.dk Cc: linux-fsdevel@vger.kernel.org, bschubert@ddn.com, io-uring@vger.kernel.org, xiaobing.li@samsung.com, csander@purestorage.com, kernel-team@meta.com References: <20251027222808.2332692-1-joannelkoong@gmail.com> <20251027222808.2332692-2-joannelkoong@gmail.com> Content-Language: en-US From: Pavel Begunkov In-Reply-To: <20251027222808.2332692-2-joannelkoong@gmail.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit On 10/27/25 22:28, Joanne Koong wrote: > Add an API for fetching the registered buffer associated with a > io_uring cmd. This is useful for callers who need access to the buffer > but do not have prior knowledge of the buffer's user address or length. Joanne, is it needed because you don't want to pass {offset,size} via fuse uapi? It's often more convenient to allocate and register one large buffer and let requests to use subchunks. Shouldn't be different for performance, but e.g. if you try to overlay it onto huge pages it'll be severely overaccounted. -- Pavel Begunkov