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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id CDB8FC433EF for ; Wed, 1 Dec 2021 23:19:45 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1353783AbhLAXWr (ORCPT ); Wed, 1 Dec 2021 18:22:47 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:55806 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1353743AbhLAXW0 (ORCPT ); Wed, 1 Dec 2021 18:22:26 -0500 Received: from mail-wr1-x42c.google.com (mail-wr1-x42c.google.com [IPv6:2a00:1450:4864:20::42c]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 6A8E6C061748; Wed, 1 Dec 2021 15:19:02 -0800 (PST) Received: by mail-wr1-x42c.google.com with SMTP id c4so55684488wrd.9; Wed, 01 Dec 2021 15:19:02 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=message-id:date:mime-version:user-agent:subject:content-language:to :cc:references:from:in-reply-to:content-transfer-encoding; bh=EzC0k6nBAvRvAw7gyjq7IDylMxnD4ESkb6qtGxCuVII=; b=b1NhGGLGDb6KYltl9BhRSXXD/t88zckVMdA+cG+MNyRXy31tAoBPePRstDUAmfAEis Swf0av6eSnIl0luetl8jSM5F7rZlcvVW+i+UjOFkC3NbAjiQ3yC5LpiSn/bfnBdLAyII jfAF5Czs/zP/y5704D2W6xJtvfPDVCw844UqAJ62C4YwRIzzfk91J0TseRwpWvqyHYjE mDUZpvN37o1NI6u9IBECwPRw0EedjVLj5lSNJgOYqI83xnIDYcaxSVApN4xOH443gTua HdQ4+h5RcOV4g5WsesDuI8wm+0JIEbN3pmcdY57bt4LPdjJUyafBBm2eUJ8s3rppphPe /fTA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:message-id:date:mime-version:user-agent:subject :content-language:to:cc:references:from:in-reply-to :content-transfer-encoding; bh=EzC0k6nBAvRvAw7gyjq7IDylMxnD4ESkb6qtGxCuVII=; b=wzfatWYlqvN7iAfYnnKkU+Z/NqytPOIWKTbQfB46yk19wlC7vNHeJJxZoS9gH+rop1 lQ5kZ+NJvAkuinK59ZChjxllNPNjxRhZwseLrrLl9wNyjgYANYx1KT6tUsPioQOL/vEp b4jLhROTQ8X+Em5/65G+xzSPPmNNvpPiWxDuT8eGXR6idoHqWmkmtp7tl60FX5pUfBUT m+H+cQ5heiNt7yye2hANqr25iDnDXrC5IBNCg354oU5pxBvSLeUBpYGgvsJpCUCERV3m fHReaY42x3ekFSvDxr093VBKh3o4YkTMABg4hACL6m+nLk/uO222Z5DZaH1ndTU0ZnEO 8SBQ== X-Gm-Message-State: AOAM531N+ROIEHVrg+LOvfwyOnkO4KxCm5lFWHUB0pDwhtxq6o0p0Z0H m9HcG/sKYgVDzgfU0AWkNtA= X-Google-Smtp-Source: ABdhPJzKFsgXCyPxwcXAFJPUaYkK9C1dCnD88t0s+vtUJcIQvcRMvd/w+qyE7NO9HgEtfKz3D2FSDw== X-Received: by 2002:adf:eb05:: with SMTP id s5mr9669480wrn.448.1638400741025; Wed, 01 Dec 2021 15:19:01 -0800 (PST) Received: from [192.168.8.198] ([185.69.144.129]) by smtp.gmail.com with ESMTPSA id m3sm956221wrv.95.2021.12.01.15.18.59 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Wed, 01 Dec 2021 15:19:00 -0800 (PST) Message-ID: <3e2caa38-27a1-986f-7187-b4e333105371@gmail.com> Date: Wed, 1 Dec 2021 23:18:36 +0000 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:91.0) Gecko/20100101 Thunderbird/91.3.2 Subject: Re: [RFC 00/12] io_uring zerocopy send Content-Language: en-US To: Martin KaFai Lau , David Ahern Cc: io-uring@vger.kernel.org, netdev@vger.kernel.org, linux-kernel@vger.kernel.org, Jakub Kicinski , Jonathan Lemon , "David S . Miller" , Willem de Bruijn , Eric Dumazet , Hideaki YOSHIFUJI , David Ahern , Jens Axboe References: <994e315b-fdb7-1467-553e-290d4434d853@gmail.com> <889c0306-afed-62cd-d95b-a20b8e798979@gmail.com> <0b92f046-5ac3-7138-2775-59fadee6e17a@gmail.com> <974b266e-d224-97da-708f-c4a7e7050190@gmail.com> <20211201215157.kgqd5attj3dytfgs@kafai-mbp.dhcp.thefacebook.com> <66dc5bcb-633d-efe8-0ccc-dcb97d08769c@gmail.com> <20211201230757.fuhnhgtbx5o22wgs@kafai-mbp.dhcp.thefacebook.com> From: Pavel Begunkov In-Reply-To: <20211201230757.fuhnhgtbx5o22wgs@kafai-mbp.dhcp.thefacebook.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: io-uring@vger.kernel.org On 12/1/21 23:07, Martin KaFai Lau wrote: > On Wed, Dec 01, 2021 at 03:35:49PM -0700, David Ahern wrote: >> On 12/1/21 2:51 PM, Martin KaFai Lau wrote: >>> >>> To tx out dummy, I did: >>> #> ip a add 10.0.0.1/24 dev dummy0 >> ^^^^^^^^ >>> >>> #> ip -4 r >>> 10.0.0.0/24 dev dummy0 proto kernel scope link src 10.0.0.1 >>> >>> #> ./send-zc -4 -D 10.0.0.(2) -t 10 udp >> ^^^^^^^^^^ >> >> Pavel's commands have: 'send-zc -4 -D -t 10 udp' >> >> I read dummy_ip_addr as the address assigned to dummy0; that's an >> important detail. You are sending to an address on that network, not the >> address assigned to the device, in which case packets are created and >> then dropped by the dummy driver - nothing actually makes it to the server. > Right, I assumed "dropped by dummy driver" is the usual intention > for using dummy, so just in case if it was the intention for > testing tx only. You are right and it seems the intention > of this command is to have server receiving the packets. I see, it seems we found the misunderstanding: For dummy device, I indeed was testing only tx part without a server, in my understanding it better approximates an actual fast NIC. I don't think dummy is even capable to pass the data, so was thinking that it's given that there is no receive side, and so no "msg_zerocopy -r". For localhost testing (with the hack), there was a server verifying data. >> >>> ip -s link show dev dummy0 >>> 2: dummy0: mtu 65535 qdisc noqueue state UNKNOWN mode DEFAULT group default qlen 1000 >>> link/ether 82:0f:e0:dc:f7:e6 brd ff:ff:ff:ff:ff:ff >>> RX: bytes packets errors dropped missed mcast >>> 0 0 0 0 0 0 >>> TX: bytes packets errors dropped carrier collsns >>> 140800890299 2150397 0 0 0 0 >>> >> -- Pavel Begunkov