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 4B848C432BE for ; Thu, 12 Aug 2021 13:46:36 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 3001F6104F for ; Thu, 12 Aug 2021 13:46:36 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S237751AbhHLNq4 (ORCPT ); Thu, 12 Aug 2021 09:46:56 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:38412 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S236152AbhHLNqy (ORCPT ); Thu, 12 Aug 2021 09:46:54 -0400 Received: from mail-pj1-x102e.google.com (mail-pj1-x102e.google.com [IPv6:2607:f8b0:4864:20::102e]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 7A492C061756; Thu, 12 Aug 2021 06:46:29 -0700 (PDT) Received: by mail-pj1-x102e.google.com with SMTP id lw7-20020a17090b1807b029017881cc80b7so15254793pjb.3; Thu, 12 Aug 2021 06:46:29 -0700 (PDT) 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=WB183lguWhFDS87ehCBje+Fiih0eLoDWXJwZXtQEnJM=; b=uxNPl+KgSeMlqAvP5yRaL+ww+r/qKjI+e/T18nAzB9BdKlmsaeGO4YU0LXLmSIVPDt 9ANube2JoOKKjr/A0f14gNfi8CZND8GrwCDiHzE1nIIvhMjs9ZIXmyPG0DUYzlgwoKkP iS7zLVoY4UZ35o5rPxmH32dLT4JFMnF8isS+6t2D2k9JjjK65+mZjQgLvY0vCzUujcxU KXuZUY5mjZeE7Ec/jF1WFvQvTKA+hvji1CfTWE/5T2ldGD93DnRZtMhLMaen5iMKs0Jr Eb4wsKH4WP9pBBbERhElUz5co64a3iWP1TeMxiXDAjjcFTt8uiSfVSiMyYveMiw7BbhZ YFBA== 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=WB183lguWhFDS87ehCBje+Fiih0eLoDWXJwZXtQEnJM=; b=ezJH7wmlkAo8wer1VuJ2l1hIhClIHgC4UhZChsp6xonEKRCPzddKhN2EelMPGNfhmk ePU9mp2yD8JHuxzumQnKh3tycrODy3BgU+dnndq3HoI7wb8Uh5WMB49NTwrMIyiHESJf Bofx3rhkaEULpKgMz9+9vSNXICgq1C/XK9x29t+LQGFguC9Xk/62F91tO5k9Avc/t4is q6Vs2tJsBtJH2XJkYul3R0oUDa4boNKuXRoLR/O0EjtncHUc3KZSYCD6rr5+f0qhOccP b94QDFQ6cpxabfqnRa8lzR5DoNv/YcUPN0XqrIQ+evzCO3tsFMNwrwvkN0V9wg8FPS/T HDDA== X-Gm-Message-State: AOAM532Yg7Wi7S/PpEorPVTdR7+i7Zn1XngcdnOJHpWqtUgroMuzyzI7 8mUOHsWMKdCbqoSQaRjxvVY= X-Google-Smtp-Source: ABdhPJzoKVXyZ/PTFLUw2x1Er7mVePAz6u27KJTyu05oXW4WKzqoD0b1ImRigJ1gmfSsl+lX18NOqA== X-Received: by 2002:a05:6a00:84e:b029:3ae:5c9:a48d with SMTP id q14-20020a056a00084eb02903ae05c9a48dmr4332754pfk.20.1628775988875; Thu, 12 Aug 2021 06:46:28 -0700 (PDT) Received: from [192.168.0.109] ([123.20.118.31]) by smtp.gmail.com with ESMTPSA id g10sm3589100pfh.120.2021.08.12.06.46.25 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Thu, 12 Aug 2021 06:46:28 -0700 (PDT) Subject: Re: [PATCH v2 1/2] udp: UDP socket send queue repair To: Eric Dumazet , linux-kernel@vger.kernel.org, netdev@vger.kernel.org Cc: davem@davemloft.net, kuba@kernel.org, yoshfuji@linux-ipv6.org, dsahern@kernel.org, willemb@google.com, pabeni@redhat.com, avagin@gmail.com, alexander@mihalicyn.com, lesedorucalin01@gmail.com References: <20210811154557.6935-1-minhquangbui99@gmail.com> <721a2e32-c930-ad6b-5055-631b502ed11b@gmail.com> From: Bui Quang Minh Message-ID: <7f3ecbaf-7759-88ae-53d3-2cc5b1623aff@gmail.com> Date: Thu, 12 Aug 2021 20:46:23 +0700 User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:78.0) Gecko/20100101 Thunderbird/78.13.0 MIME-Version: 1.0 In-Reply-To: <721a2e32-c930-ad6b-5055-631b502ed11b@gmail.com> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 8/11/2021 11:14 PM, Eric Dumazet wrote: > > > On 8/11/21 5:45 PM, Bui Quang Minh wrote: >> In this patch, I implement UDP_REPAIR sockoption and a new path in >> udp_recvmsg for dumping the corked packet in UDP socket's send queue. >> >> A userspace program can use recvmsg syscall to get the packet's data and >> the msg_name information of the packet. Currently, other related >> information in inet_cork that are set in cmsg are not dumped. >> >> While working on this, I was aware of Lese Doru Calin's patch and got some >> ideas from it. > > > What is the use case for this feature, adding a test in UDP fast path ? This feature is used to help CRIU to dump CORKed UDP packet in send queue. I'm sorry for being not aware of the performance perspective here. > IMO, TCP_REPAIR hijacking standard system calls was a design error, > we should have added new system calls. You are right that adding new system calls is a better approach. What do you think about adding a new option in getsockopt approach? Thanks, Quang Minh.