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=-0.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED 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 C0A2FC433DF for ; Wed, 20 May 2020 22:35:46 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 8D2D62088E for ; Wed, 20 May 2020 22:35:46 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728550AbgETWfp (ORCPT ); Wed, 20 May 2020 18:35:45 -0400 Received: from mga14.intel.com ([192.55.52.115]:2464 "EHLO mga14.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728019AbgETWfp (ORCPT ); Wed, 20 May 2020 18:35:45 -0400 IronPort-SDR: sb/rL2+03NlW44RZKUsDU3u+V2TieCIR5uXK7gY8ptXT0YHImKU4POpFFQD7662ZJq3SEjAiVG 1k/KIvz81+Yg== X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from fmsmga006.fm.intel.com ([10.253.24.20]) by fmsmga103.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 20 May 2020 15:35:44 -0700 IronPort-SDR: ZEJSJqmURq3x/rur5ku7fc6VeKIe7MNloL9OorldYn2IJaY6dNX5V6iSf7hr/T6eqrWC7JuSuM yn/Sv0mTKxBg== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.73,415,1583222400"; d="scan'208";a="466694791" Received: from alopezch-mobl.amr.corp.intel.com (HELO ellie) ([10.213.162.205]) by fmsmga006.fm.intel.com with ESMTP; 20 May 2020 15:35:44 -0700 From: Vinicius Costa Gomes To: Andre Guedes , Jakub Kicinski Cc: Jose.Abreu@synopsys.com, vladimir.oltean@nxp.com, po.liu@nxp.com, m-karicheri2@ti.com, intel-wired-lan@lists.osuosl.org, netdev@vger.kernel.org, olteanv@gmail.com, David Miller Subject: Re: [Intel-wired-lan] [next-queue RFC 0/4] ethtool: Add support for frame preemption In-Reply-To: <159001094525.59702.8769665430201911136@sdkini-mobl1.amr.corp.intel.com> References: <20200516012948.3173993-1-vinicius.gomes@intel.com> <20200516.133739.285740119627243211.davem@davemloft.net> <20200516.151932.575795129235955389.davem@davemloft.net> <87wo59oyhr.fsf@intel.com> <20200518135613.379f6a63@kicinski-fedora-pc1c0hjn.dhcp.thefacebook.com> <87h7wcq4nx.fsf@intel.com> <20200518152259.29d2e3c7@kicinski-fedora-pc1c0hjn.dhcp.thefacebook.com> <87blmkq1y3.fsf@intel.com> <20200518160906.40e9d8bb@kicinski-fedora-pc1c0hjn.dhcp.thefacebook.com> <159001094525.59702.8769665430201911136@sdkini-mobl1.amr.corp.intel.com> Date: Wed, 20 May 2020 15:35:44 -0700 Message-ID: <874ksamdz3.fsf@intel.com> 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 Andre Guedes writes: >> If standard defines it as per-MAC and we can reasonably expect vendors >> won't try to "add value" and make it per queue (unlikely here AFAIU), >> then for this part ethtool configuration seems okay to me. > > Before we move forward with this hybrid approach, let's recap a few points that > we discussed in the previous thread and make sure it addresses them > properly. Thanks for bringing them up. > > 1) Frame Preemption (FP) can be enabled without EST, as described in IEEE > 802.1Q. In this case, the user has to create a dummy EST schedule in taprio > just to be able to enable FP, which doesn't look natural. What I meant by "dummy" schedule, is to configure taprio without specifying any "sched-entry". And since we have support for adding schedules during runtime, this might be even useful in general. > > 2) Mpqrio already looks overloaded. Besides mapping traffic classes into > hardware queues, it also supports different modes and traffic shaping. Do we > want to add yet another setting to it? I also don't see this as a problem. The parameters that mqprio has carry a lot of information, but the number of them is not that big. Cheers, -- Vinicius