From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from casper.infradead.org (casper.infradead.org [90.155.50.34]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 1D2BF6ADD; Sun, 23 Mar 2025 14:33:43 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=90.155.50.34 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1742740426; cv=none; b=TFZV0Bi/Ns21gh08qP4dY5Mx+E6VXPXS3IvxxvyGi8ICPvuxzUI3IaqSq31dSmnKVwpheoGsdc1ooV6XbqBpcs+ugJh/LseYVPDb/wJLUJGuvXsS0J3swvY+TWEueGqzXmdrVI8rivoWaBNsX4IBypyhkewSc8xuSexVABEzbZc= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1742740426; c=relaxed/simple; bh=rKINkbhYV6hTVFAbzvACFUklqCfglI92COp/9PBq9eY=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=lJ9ipFwiPTGF97SodkaePMSa+uUN23nI1EKfkXGHIPzC1Ld0BBPY5qQDyU1NN7UuDHV74x/l3+RPViecFUXDA0CpjRhepateZqiT35WbIXNz98YgSdoakVodeGUCQWMG80Wkn1MFv1KgHXX5Wa9gefbsSt7g7YWDDCYaKP6Isn8= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=infradead.org; spf=none smtp.mailfrom=infradead.org; dkim=pass (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b=kxK36Rxm; arc=none smtp.client-ip=90.155.50.34 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=infradead.org Authentication-Results: smtp.subspace.kernel.org; spf=none smtp.mailfrom=infradead.org Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="kxK36Rxm" DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=casper.20170209; h=In-Reply-To:Content-Type:MIME-Version: References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description; bh=zGBTpFLK0UixlShYpg/OWoA6cRXQfCGU0ZBvGLWIcIo=; b=kxK36Rxm0wzobQNar9Cv3m5UPz 0G/kYXg/jvR3ydP9fmiTHxM6kftq9uKF0ATEvxJsc3aqu7xSnU6QoxbHf7xQPRLKi0l0VOubdkOTf kUVa5+BCmN2Ds/f8rEIVDWzzx4j0sLLTvJCTEw/9FL2I7cuOqcBIDXSwnjrCF6GFarhbgjGt4s3Er fhcmPHrHOxcOt7FZwZG7dmkfz48YvC5h09KgiCN3Hyp+AkQiVkmsoadosGyN2xk86iXNO50ZGv+z8 FyLVqGcW1EYM6XeYYjZffoat3bKdcY/qzVi+3gKvGnOPuXVgP4+T7ghDqYcXD9ktlnth3PqWwLKoe aGaAoHIg==; 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> Precedence: bulk X-Mailing-List: netfs@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: 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