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 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 6BED6C433DF for ; Mon, 18 May 2020 19:05:10 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 4427120657 for ; Mon, 18 May 2020 19:05:10 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726292AbgERTFI (ORCPT ); Mon, 18 May 2020 15:05:08 -0400 Received: from mga03.intel.com ([134.134.136.65]:12203 "EHLO mga03.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726249AbgERTFF (ORCPT ); Mon, 18 May 2020 15:05:05 -0400 IronPort-SDR: rnkoKu9WqUS21oue+MrIaEPJhn3CFtmaqAeeFRpSuLfqSBoIPct8rOSsuSQ81l7LPSgbSVcvIE YnhZOeTT9EbA== X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from fmsmga006.fm.intel.com ([10.253.24.20]) by orsmga103.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 18 May 2020 12:05:05 -0700 IronPort-SDR: CKN7mrYhZdBl5EPysAv1eSPnvqpEUHmG2tRwwcNDEXqUnA6luRwh3AceAMODl0bsmfhMqWfOVl tBDotq4nNZwg== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.73,407,1583222400"; d="scan'208";a="465863900" Received: from melassa-mobl1.amr.corp.intel.com (HELO ellie) ([10.212.228.130]) by fmsmga006.fm.intel.com with ESMTP; 18 May 2020 12:05:04 -0700 From: Vinicius Costa Gomes To: David Miller , olteanv@gmail.com Cc: intel-wired-lan@lists.osuosl.org, jeffrey.t.kirsher@intel.com, netdev@vger.kernel.org, vladimir.oltean@nxp.com, po.liu@nxp.com, m-karicheri2@ti.com, Jose.Abreu@synopsys.com Subject: Re: [next-queue RFC 0/4] ethtool: Add support for frame preemption In-Reply-To: <20200516.151932.575795129235955389.davem@davemloft.net> References: <20200516012948.3173993-1-vinicius.gomes@intel.com> <20200516.133739.285740119627243211.davem@davemloft.net> <20200516.151932.575795129235955389.davem@davemloft.net> Date: Mon, 18 May 2020 12:05:04 -0700 Message-ID: <87wo59oyhr.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 Hi, David Miller writes: > From: Vladimir Oltean > Date: Sun, 17 May 2020 00:03:39 +0300 > >> As to why this doesn't go to tc but to ethtool: why would it go to tc? > > Maybe you can't %100 duplicate the on-the-wire special format and > whatever, but the queueing behavior ABSOLUTELY you can emulate in > software. Just saying what Vladimir said in different words: the queueing behavior is already implemented in software, by mqprio or taprio, for example. That is to say, if we add frame preemption support to those qdiscs all they will do is pass the information to the driver, and that's it. They won't be able to use that information at all. The mental model I have for this feature is that is more similar to the segmentation offloads, energy efficient ethernet or auto-negotiation than it is to a traffic shaper like CBS. > > And then you have the proper hooks added for HW offload which can > do the on-the-wire stuff. > > That's how we do these things, not with bolted on ethtool stuff. Cheers, -- Vinicius