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=-2.6 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_PASS,USER_AGENT_MUTT autolearn=ham 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 A4824C43381 for ; Tue, 26 Feb 2019 08:20:58 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 719C7213A2 for ; Tue, 26 Feb 2019 08:20:58 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="mbWlpWdg" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726833AbfBZIU5 (ORCPT ); Tue, 26 Feb 2019 03:20:57 -0500 Received: from mail-pg1-f194.google.com ([209.85.215.194]:37258 "EHLO mail-pg1-f194.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726298AbfBZIU4 (ORCPT ); Tue, 26 Feb 2019 03:20:56 -0500 Received: by mail-pg1-f194.google.com with SMTP id q206so5858641pgq.4 for ; Tue, 26 Feb 2019 00:20:56 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to:user-agent; bh=A/r6twztrGCc1D53wh21SOG4nPOdvykAdCIGcLElN0Q=; b=mbWlpWdgDsZKtkt3Q4OhO/8je/hyhxJE8kSvfy6LyzJBO8/qJUAEzkzRNxsdZe6F3/ +a8RMIvI/Kz7EgeZtJ8sYX10lDCtUEBP6mycCt2H+0n1gPYBeVKg5GaPaoWMePvejbVX m4PyrZWbv+w4lmvfypoScsGRILLJLFeKYfv3F0IOgDGqgCt2hCqz2ALHmk8D69BcJLRH eXzLy7DJFYH/4GJ29OoPMW31qd7x9YGUtxyHLPGaMh1YJDP+pUTald1upfX5j5BCq9zV eWMM2t7+rHJ5uJO26Ms5J3d9ANn7YoIid1+1j/kY1oYe2lHcd80qfMu9ggKl/fNxB4Uk T59g== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to:user-agent; bh=A/r6twztrGCc1D53wh21SOG4nPOdvykAdCIGcLElN0Q=; b=J6CGJyMFSb8Ll7lZHp7T3m/uXibe4qHRH46lj4bg2hkDdukC/vQCtGmsFiOoP+VR78 C/rIqrLQmKcMHTOoe06n3XKYSu6SepYDU7r9Ifacaalo6RmphdnR7vmozO58LXaNAHRj 45ioLBdgtak7gW5EjkjWvsutw7FgAD8MZRUEwpzT5cwFQU+frlrR+BX+nO5q5csc10Nl 3YzB3thmRM5iKD5miFbRW3Bt4hbwF6jEOBkz8B10Gr50875NnCRIItjTYZMqJMfhdXjS 7a72L+Jf9T9TaraMFg+r9CpvRM+mDLVW4PF8qLwm0q9fNHPBulkj/lUz3HuT6ci7/QWs ukbg== X-Gm-Message-State: AHQUAubSfC9YS9BRJhG5UexZpYekLAyEPCPvGW7xrl49Ck72RFT7IPN/ aNzTeEzl5Dh9WDLr8iX8mKg= X-Google-Smtp-Source: AHgI3IaVlKUoKjleJMNMn0u20BgzdYJVqYb+higv/EHCaYhaYMEtMoNgjGvVy3AbKSa377K/UdBE2Q== X-Received: by 2002:a63:c204:: with SMTP id b4mr23162939pgd.335.1551169255536; Tue, 26 Feb 2019 00:20:55 -0800 (PST) Received: from Inspiron-3521 ([106.216.180.155]) by smtp.gmail.com with ESMTPSA id a5sm13560421pgv.12.2019.02.26.00.20.51 (version=TLS1_2 cipher=ECDHE-RSA-CHACHA20-POLY1305 bits=256/256); Tue, 26 Feb 2019 00:20:54 -0800 (PST) Date: Tue, 26 Feb 2019 13:50:46 +0530 From: Leslie Monis To: Stephen Hemminger Cc: davem@davemloft.net, netdev@vger.kernel.org, "Mohit P . Tahiliani" , Dave Taht , Jamal Hadi Salim Subject: Re: [PATCH net-next v3 0/7] net: sched: pie: align PIE implementation with RFC 8033 Message-ID: <20190226082046.GA2266@Inspiron-3521> References: <20190225191001.26797-1-lesliemonis@gmail.com> <20190225163811.4a6b477b@shemminger-XPS-13-9360> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20190225163811.4a6b477b@shemminger-XPS-13-9360> User-Agent: Mutt/1.9.4 (2018-02-28) Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org On Mon, Feb 25, 2019 at 04:38:11PM -0800, Stephen Hemminger wrote: > On Tue, 26 Feb 2019 00:39:54 +0530 > Leslie Monis wrote: > > > The current implementation of the PIE queuing discipline is according to the > > IETF draft [http://tools.ietf.org/html/draft-pan-aqm-pie-00] and the paper > > [PIE: A Lightweight Control Scheme to Address the Bufferbloat Problem]. > > However, a lot of necessary modifications and enhancements have been proposed > > in RFC 8033, which have not yet been incorporated in the source code of Linux. > > This patch series helps in achieving the same. > > > > Performance tests carried out using Flent [https://flent.org/] > > > > Changes from v2 to v3: > > - Used div_u64() instead of direct division after explicit type casting as > > recommended by David > > > > Changes from v1 to v2: > > - Excluded the patch setting PIE dynamically active/inactive as the test > > results were unsatisfactory > > - Fixed a scaling issue when adding more auto-tuning cases which caused > > local variables to underflow > > - Changed the long if/else chain to a loop as suggested by Stephen > > - Changed the position of the accu_prob variable in the pie_vars > > structure as recommended by Stephen > > > > Mohit P. Tahiliani (7): > > net: sched: pie: change value of QUEUE_THRESHOLD > > net: sched: pie: change default value of pie_params->target > > net: sched: pie: change default value of pie_params->tupdate > > net: sched: pie: change initial value of pie_vars->burst_time > > net: sched: pie: add more cases to auto-tune alpha and beta > > net: sched: pie: add derandomization mechanism > > net: sched: pie: update references > > > > include/uapi/linux/pkt_sched.h | 2 +- > > net/sched/sch_pie.c | 107 ++++++++++++++++++++------------- > > 2 files changed, 66 insertions(+), 43 deletions(-) > > Are you concerned at all that changes to default values might change > expected behavior of existing users? Hi Stephen, As Dave mentioned, the changes which we have made do not really change the behaviour of the aqm drastically. Our performance tests show that these changes improve performance without any side-effects. So existing users (if there are any) should not be negatively affected in any way. Leslie