From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 2DAD1C3ABD8 for ; Fri, 16 May 2025 22:31:54 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:Content-Transfer-Encoding: Content-Type:MIME-Version:References:In-Reply-To:Message-ID:Subject:Cc:To: From:Date:Reply-To:Content-ID:Content-Description:Resent-Date:Resent-From: Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=X11KdZycco3RW/kmTzYI2J/sL8E0OjWYVL9EAifO5hs=; b=TGcZFE2/vmqnkJWgrBgueOhIMa Q7sPuwk9t/PfreJ7qTTgnJLDjdFKpZB3FF7frIAcB9vA6tK5kYD9lxwSnzuz35/fp3PRar7Efagbo uh6tIwWzXbDZVBNeRNPZZgqbaEkorIYEZwCmhCylhP6o80zQiU1J7DpXIXE0Nt4AunVPZNbP7/BQp NVKmOgMitc/yFdA2BDTlCQIvxckOB0216dTZsKBnGWec1hNalcTzJD1lCP9+BYzVWliEuc4TbDKWe 96C5EYO40ByCHNQGc+snwdC/7AJWvn3EEfMWkhwFIcQkj6pKU9OBd3eoq3n9BajdvZHl9vZwXq2uC E8f0UhxA==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.98.2 #2 (Red Hat Linux)) id 1uG3ao-00000004kkf-2rBo; Fri, 16 May 2025 22:31:50 +0000 Received: from sea.source.kernel.org ([172.234.252.31]) by bombadil.infradead.org with esmtps (Exim 4.98.2 #2 (Red Hat Linux)) id 1uG3am-00000004kkG-07hn for linux-nvme@lists.infradead.org; Fri, 16 May 2025 22:31:49 +0000 Received: from smtp.kernel.org (transwarp.subspace.kernel.org [100.75.92.58]) by sea.source.kernel.org (Postfix) with ESMTP id 5A8364484C; Fri, 16 May 2025 22:31:47 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 7D998C4CEE4; Fri, 16 May 2025 22:31:46 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1747434707; bh=j1TzjQ6x1h5RRusIRAxCzoJzqDcMuofCLRpeIjOayrM=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=q+EbV0zePfMiLNAhwB0s7/x9bwNJR2vcrhn/I2aT7tJGVpWA6MVSE//HZBr0jeZjj +A6ef6qY2CX0FVj4alj5UydwsenwRG5VTQ9TYeri39YfxkoOOvwKB3IHItpRTey4nG huoxrqqAN5fApQCaTdcBLIUMJvOiYdplK1yiPhORKSa2fmU+2DK1TOZ21taEtOIfPT HoElvP4nY0OPDIxcI4lI75L7eJI7mjUjmGbq8KZOYSaXt8inHEvE5c4JcYavj0u/J2 8QmoV3MUhv3CU3P9RlUMcT6ZDtUyI8NSRueNwFLhy9y2n10iIWinhJ/jQnSKWHJdh1 iV+6WyOUmGIZQ== Date: Fri, 16 May 2025 15:31:45 -0700 From: Jakub Kicinski To: Aurelien Aptel Cc: Eric Dumazet , linux-nvme@lists.infradead.org, netdev@vger.kernel.org, sagi@grimberg.me, hch@lst.de, kbusch@kernel.org, axboe@fb.com, chaitanyak@nvidia.com, davem@davemloft.net, Boris Pismenny , aurelien.aptel@gmail.com, smalin@nvidia.com, malin1024@gmail.com, ogerlitz@nvidia.com, yorayz@nvidia.com, galshalom@nvidia.com, mgurtovoy@nvidia.com, tariqt@nvidia.com, gus@collabora.com, pabeni@redhat.com, dsahern@kernel.org, ast@kernel.org, jacob.e.keller@intel.com Subject: Re: [PATCH v28 01/20] net: Introduce direct data placement tcp offload Message-ID: <20250516153145.602fc02d@kernel.org> In-Reply-To: <2537c2gzk6x.fsf@nvidia.com> References: <20250430085741.5108-1-aaptel@nvidia.com> <20250430085741.5108-2-aaptel@nvidia.com> <2537c2gzk6x.fsf@nvidia.com> MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20250516_153148_097048_CADA03C7 X-CRM114-Status: UNSURE ( 8.38 ) X-CRM114-Notice: Please train this message. X-BeenThere: linux-nvme@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "Linux-nvme" Errors-To: linux-nvme-bounces+linux-nvme=archiver.kernel.org@lists.infradead.org On Fri, 16 May 2025 17:47:34 +0300 Aurelien Aptel wrote: > The offload works by calling the iter copy functions while skipping the > memcpy (see patch 3). We think the unreadable bit is getting close to > what we want if it wasn't for the skb_datagram_iter() check. Maybe the > bit could be unset at a later stage but it's not clear where. Getting rid of the hack in iov_iter may be for the best, actually. It's pretty ugly.