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 X-Spam-Level: X-Spam-Status: No, score=-4.2 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,NICE_REPLY_A,SPF_HELO_NONE, SPF_PASS,USER_AGENT_SANE_1 autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 8FF91C433FE for ; Fri, 11 Dec 2020 21:20:33 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 3DD852409B for ; Fri, 11 Dec 2020 21:20:33 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2403775AbgLKUA4 (ORCPT ); Fri, 11 Dec 2020 15:00:56 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:39226 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2390134AbgLKUAf (ORCPT ); Fri, 11 Dec 2020 15:00:35 -0500 Received: from mail-oi1-x241.google.com (mail-oi1-x241.google.com [IPv6:2607:f8b0:4864:20::241]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 1D9DEC0613D3 for ; Fri, 11 Dec 2020 11:59:55 -0800 (PST) Received: by mail-oi1-x241.google.com with SMTP id k2so11141702oic.13 for ; Fri, 11 Dec 2020 11:59:55 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=subject:to:cc:references:from:message-id:date:user-agent :mime-version:in-reply-to:content-language:content-transfer-encoding; bh=GXouTMg9z7FxGREV13t5lB9zURmuWrbw3x7YOJeBTgM=; b=uEyEY3EPAxWX3oGWTVNPUuEUfSH8bFqor4l/2fgf60BGehsY1bJ41QWiUEJ5XuKljy yNF2EMdJI0/VPcyTfOg6gU598Ppdx9lKtzdsoA5u2KspNJkMD5qWHD5Yyk90WB+fVHqF zM7As+I+S2ySbShGJsY80spNK0eZnSvab90q5RpmZFCWlrIj+gKOu/JXwHDU+amEvl4b NTDPzhllgUd8iZUn4d0RvKZd9R3jIiLnbQaXp9qU++PyRKHoY70YwMC6eBKqi6v+NgUU bBZZePrYoMggpeZ2fNv75GuBLe7z9QpWEjgrlEZ+DHjmWSheZXKj+NXqqLcQm1A7HU99 Amkw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:subject:to:cc:references:from:message-id:date :user-agent:mime-version:in-reply-to:content-language :content-transfer-encoding; bh=GXouTMg9z7FxGREV13t5lB9zURmuWrbw3x7YOJeBTgM=; b=E3twtnBGk/qt7J1xNzsFpF8YN4Ta4XTtsfxYIS2xCmJcEDExzh5TLip8147+V0QUjt IvSxhfavD86l9qTaVEDX6q9m2+Gcl4i4ocYKUsSrQh/eQuXXutEJa/7b4TpkRhJraQyU WNu2AQQxCeyW/e31CvGkJC95fw6aGZfyqNP9IJuExNcO8o7XY+NFUCO28C1unawuv3ng ENZMco2dfWV3QJ9LwoW3L9nXLpK5Lay5fHDQeePxHj/5+86gfQ9VglARqsgGZ6i3ST7U 3Ip8BRiLrFbqef/mGzDQQcpDxiC8DxsWgDzcWpeZN3KW3UFkVX+iCgcHgjGDcvnQfPnW dO+A== X-Gm-Message-State: AOAM532cF5vssTrkFpzUfwTT/TMQLawpBdmm+8ssa4gqo/+8clQS2BcZ KcwAn+/r1La9UugW8TSCsNg= X-Google-Smtp-Source: ABdhPJzxtMM7NQoSo5eoOOehPBdJgEAWO056zfguSFANeHCqz4IKmjGwP0JfVn+DZVXqR46X9uVNvA== X-Received: by 2002:aca:1b1a:: with SMTP id b26mr10534497oib.43.1607716794557; Fri, 11 Dec 2020 11:59:54 -0800 (PST) Received: from Davids-MacBook-Pro.local ([2601:282:800:dc80:6139:6f39:a803:1a61]) by smtp.googlemail.com with ESMTPSA id l5sm2014127ooo.2.2020.12.11.11.59.52 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Fri, 11 Dec 2020 11:59:53 -0800 (PST) Subject: Re: [PATCH v1 net-next 02/15] net: Introduce direct data placement tcp offload To: Jakub Kicinski Cc: Boris Pismenny , Boris Pismenny , davem@davemloft.net, saeedm@nvidia.com, hch@lst.de, sagi@grimberg.me, axboe@fb.com, kbusch@kernel.org, viro@zeniv.linux.org.uk, edumazet@google.com, boris.pismenny@gmail.com, linux-nvme@lists.infradead.org, netdev@vger.kernel.org, benishay@nvidia.com, ogerlitz@nvidia.com, yorayz@nvidia.com, Ben Ben-Ishay , Or Gerlitz , Yoray Zack , Boris Pismenny References: <20201207210649.19194-1-borisp@mellanox.com> <20201207210649.19194-3-borisp@mellanox.com> <6f48fa5d-465c-5c38-ea45-704e86ba808b@gmail.com> <65dc5bba-13e6-110a-ddae-3d0c260aa875@gmail.com> <921a110f-60fa-a711-d386-39eeca52199f@gmail.com> <20201210180108.3eb24f2b@kicinski-fedora-pc1c0hjn.DHCP.thefacebook.com> <5cadcfa0-b992-f124-f006-51872c86b804@gmail.com> <20201211104445.30684242@kicinski-fedora-pc1c0hjn.dhcp.thefacebook.com> From: David Ahern Message-ID: <281b12de-7730-05a7-1187-e4f702c19cda@gmail.com> Date: Fri, 11 Dec 2020 12:59:52 -0700 User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.16; rv:78.0) Gecko/20100101 Thunderbird/78.5.1 MIME-Version: 1.0 In-Reply-To: <20201211104445.30684242@kicinski-fedora-pc1c0hjn.dhcp.thefacebook.com> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org On 12/11/20 11:45 AM, Jakub Kicinski wrote: > Ack, these patches are not exciting (to me), so I'm wondering if there > is a better way. The only reason NIC would have to understand a ULP for > ZC is to parse out header/message lengths. There's gotta be a way to > pass those in header options or such... > > And, you know, if we figure something out - maybe we stand a chance > against having 4 different zero copy implementations (this, TCP, > AF_XDP, netgpu) :( AF_XDP is for userspace IP/TCP/packet handling. netgpu is fundamentally kernel stack socket with zerocopy direct to userspace buffers. Yes, it has more complications like the process is running on a GPU, but essential characteristics are header / payload split, a kernel stack managed socket, and dedicated H/W queues for the socket and those are all common to what the nvme patches are doing. So, can we create a common framework for those characteristics which enables other use cases (like a more generic Rx zerocopy)?