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=-0.9 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS 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 D2CC1C33CB0 for ; Mon, 13 Jan 2020 11:44:45 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id A8D992084D for ; Mon, 13 Jan 2020 11:44:45 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="TJxSmKIi" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728516AbgAMLop (ORCPT ); Mon, 13 Jan 2020 06:44:45 -0500 Received: from us-smtp-1.mimecast.com ([207.211.31.81]:29723 "EHLO us-smtp-delivery-1.mimecast.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1726934AbgAMLoo (ORCPT ); Mon, 13 Jan 2020 06:44:44 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1578915883; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=xbmiE7SY+fBHFcH04ZWzxFBnS2F/540t7NKmUNMrr4Q=; b=TJxSmKIiKxsAebEHNplTc+rVE1/EOykyTMlTBr75eeEJdFAsetB4UgWmRUyyW2NxJr7QIb rTTKzmuuzZdiWt6MWelqLaHZ4aaePq5eh+lRPkuacyAwtHqfFESlTsoZIhCC6AFZ5YEtSX kcJxgVmiucXWJJSzUDtprjp8pSyy6M0= Received: from mail-lj1-f200.google.com (mail-lj1-f200.google.com [209.85.208.200]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-329-mgVQeogDOtW0n37pREtFKQ-1; Mon, 13 Jan 2020 06:44:41 -0500 X-MC-Unique: mgVQeogDOtW0n37pREtFKQ-1 Received: by mail-lj1-f200.google.com with SMTP id j23so1877045lji.23 for ; Mon, 13 Jan 2020 03:44:41 -0800 (PST) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:in-reply-to:references:date :message-id:mime-version; bh=xbmiE7SY+fBHFcH04ZWzxFBnS2F/540t7NKmUNMrr4Q=; b=jq+OyyQ4Do2IjfH2CAfC+SCVjH92AeUlZNqCSrFzd7Whvf7ojcKtojSObfKOK3cl4S bxN9RwBOvQI3gbtAZf1UolbPv9+yDqtDKTGfSv1KnYQFfqBEFTIDu/9mjtUxQ4672G7b igM766c4fyD/O5kp1vk0afXt1iU+k00FNsqF+jYV/Kx8bWWd7OfnOKVpGOpJyeRaiz3w +A7GLf84hTbZPg2pF0oyvLnX2x4IZsjW1CGo5fcXeQ7y83NorA2tqp++zqZUzzGaJ63a Ss7mrk3fAhVChS5itC2VbSLgdkHJJ8EV0dslNCrvjseGqS967hqP4Y4WN5bvaRJ7BnaT kk5A== X-Gm-Message-State: APjAAAW9F7T5olrmoXGudDYo13GI8aSW/9z8BnjmxRyLmMBuRCEPTp8c F4pnE7zV34q+nkT+unJfEj3jLFT017INBOCPazzxFNFShGbk3uur3wLz3w4RhdYnmqi3TB2vwMB 9aPGvA5J/LTK9O6oV X-Received: by 2002:a2e:b4cb:: with SMTP id r11mr10408828ljm.68.1578915880476; Mon, 13 Jan 2020 03:44:40 -0800 (PST) X-Google-Smtp-Source: APXvYqzKtx+j98eK647oeBa3CCnjxTV9+G20YrkAgRnR4Cz/0nv59+gfcHS27SnJhToDYaHagAlIMw== X-Received: by 2002:a2e:b4cb:: with SMTP id r11mr10408816ljm.68.1578915880298; Mon, 13 Jan 2020 03:44:40 -0800 (PST) Received: from alrua-x1.borgediget.toke.dk ([2a0c:4d80:42:443::2]) by smtp.gmail.com with ESMTPSA id a15sm5627067lfi.60.2020.01.13.03.44.39 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 13 Jan 2020 03:44:39 -0800 (PST) Received: by alrua-x1.borgediget.toke.dk (Postfix, from userid 1000) id CACEB1804D6; Mon, 13 Jan 2020 12:44:38 +0100 (CET) From: Toke =?utf-8?Q?H=C3=B8iland-J=C3=B8rgensen?= To: Jakub Kicinski , gautamramk@gmail.com Cc: netdev@vger.kernel.org, "Mohit P. Tahiliani" , Jamal Hadi Salim , "David S . Miller" , Dave Taht , Leslie Monis , "Sachin D . Patil" , "V . Saicharan" , Mohit Bhasi Subject: Re: [PATCH net-next v3 2/2] net: sched: add Flow Queue PIE packet scheduler In-Reply-To: <20200112173624.5f7b754b@cakuba> References: <20200110062657.7217-1-gautamramk@gmail.com> <20200110062657.7217-3-gautamramk@gmail.com> <20200112173624.5f7b754b@cakuba> X-Clacks-Overhead: GNU Terry Pratchett Date: Mon, 13 Jan 2020 12:44:38 +0100 Message-ID: <87eew3wpg9.fsf@toke.dk> MIME-Version: 1.0 Content-Type: text/plain Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org Jakub Kicinski writes: > On Fri, 10 Jan 2020 11:56:57 +0530, gautamramk@gmail.com wrote: >> From: "Mohit P. Tahiliani" >> >> Principles: >> - Packets are classified on flows. >> - This is a Stochastic model (as we use a hash, several flows might >> be hashed on the same slot) >> - Each flow has a PIE managed queue. >> - Flows are linked onto two (Round Robin) lists, >> so that new flows have priority on old ones. >> - For a given flow, packets are not reordered. >> - Drops during enqueue only. >> - ECN capability is off by default. >> - ECN threshold is at 10% by default. >> - Uses timestamps to calculate queue delay by default. >> >> Usage: >> tc qdisc ... fq_pie [ limit PACKETS ] [ flows NUMBER ] >> [ alpha NUMBER ] [ beta NUMBER ] >> [ target TIME us ] [ tupdate TIME us ] >> [ memory_limit BYTES ] [ quantum BYTES ] >> [ ecnprob PERCENTAGE ] [ [no]ecn ] >> [ [no]bytemode ] [ [no_]dq_rate_estimator ] >> >> defaults: >> limit: 10240 packets, flows: 1024 >> alpha: 1/8, beta : 5/4 >> target: 15 ms, tupdate: 15 ms (in jiffies) >> memory_limit: 32 Mb, quantum: device MTU >> ecnprob: 10%, ecn: off >> bytemode: off, dq_rate_estimator: off > > Some reviews below, but hopefully someone who knows more about qdiscs > will still review :) I looked it over, and didn't find anything you hadn't already pointed out below. It's pretty obvious that this started out as a copy of sch_fq_codel. Which is good, because that's pretty solid. And bad, because that means it introduces another almost-identical qdisc without sharing any of the code... I think it would be worthwhile to try to consolidate things at some point. Either by just merging code from fq_{codel,pie}, but another option would be to express fq_codel and fq_pie using the fq{,_impl}.h includes. Maybe even sch_cake as well, but that may take a bit more work. Not sure if we should require this before merging fq_pie, or just leave it as a possible enhancement for later? WDYT? -Toke