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Received: from willy by casper.infradead.org with local (Exim 4.98 #2 (Red Hat Linux)) id 1twMOR-00000006gTC-1B8U; Sun, 23 Mar 2025 14:33:39 +0000 Date: Sun, 23 Mar 2025 14:33:39 +0000 From: Matthew Wilcox To: Christoph Hellwig Cc: David Howells , Leon Romanovsky , Christian Brauner , Chuck Lever , Steve French , Ilya Dryomov , netfs@lists.linux.dev, linux-fsdevel@vger.kernel.org, linux-block@vger.kernel.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org Subject: Re: [RFC PATCH 0/4] iov_iter: Add composite, scatterlist and skbuff iterator types Message-ID: References: <20250321161407.3333724-1-dhowells@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: X-Rspamd-Queue-Id: CA3064000A X-Rspamd-Server: rspam05 X-Rspam-User: X-Stat-Signature: amfyexfyxguwsx9xwbxqnmt31j8je56o X-HE-Tag: 1742740423-175162 X-HE-Meta: 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 cl9BmYJ2 fO2vGluDi8jzxGVK3/HQrxqHBiEHbJdsaVI0OozYTto6CSvhitEhaPHNpJaAIuDwHt4AoBsiq454YUtHmsCbLo52PYC2TEaFTBnzgs6TkVJraLtwKgef8CDcJSbsydO7Ksvyd9k2WnyDyYMTvfp3MCo5BJt4Z9EulXjCexJ2xksSqas45bFe0UYzbuGJy94gwsX4ZteJoYMI1idknzrQ6Ul0vQ/ZaSXgTbq8cPoIC049mzhXMnTGS1/MuywUVS+zfB93VkwtsbBKVhi1zjwkDgWJ/ug== X-Bogosity: Ham, tests=bogofilter, spamicity=0.000020, 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 Sat, Mar 22, 2025 at 11:21:28PM -0700, Christoph Hellwig wrote: > This is going entirely in the wrong direction. We don't need more iter > types but less. The reason why we have to many is because the underlying > representation of the ranges is a mess which goes deeper than just the > iterator, because it also means we have to convert between the > underlying representations all the time. > > E.g. the socket code should have (and either has for a while or at least > there were patches) been using bio_vecs instead of reinventing them as sk > fragment. The crypto code should not be using scatterlists, which are a I did this work six years ago -- see 8842d285bafa Unfortunately, networking is full of inconsiderate arseholes who backed it out without even talking to me in 21d2e6737c97