Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 59E4FC433FE for ; Mon, 15 Nov 2021 11:07:36 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 4546661101 for ; Mon, 15 Nov 2021 11:07:36 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S237669AbhKOLKY convert rfc822-to-8bit (ORCPT ); Mon, 15 Nov 2021 06:10:24 -0500 Received: from mslow1.mail.gandi.net ([217.70.178.240]:50923 "EHLO mslow1.mail.gandi.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231154AbhKOLJZ (ORCPT ); Mon, 15 Nov 2021 06:09:25 -0500 Received: from relay9-d.mail.gandi.net (unknown [217.70.183.199]) by mslow1.mail.gandi.net (Postfix) with ESMTP id D14E6CFBD7; Mon, 15 Nov 2021 11:02:21 +0000 (UTC) Received: (Authenticated sender: clement.leger@bootlin.com) by relay9-d.mail.gandi.net (Postfix) with ESMTPSA id EF225FF809; Mon, 15 Nov 2021 11:01:52 +0000 (UTC) Date: Mon, 15 Nov 2021 11:58:05 +0100 From: =?UTF-8?B?Q2zDqW1lbnQgTMOpZ2Vy?= To: Vladimir Oltean Cc: "David S. Miller" , Jakub Kicinski , Rob Herring , Claudiu Manoil , Alexandre Belloni , "UNGLinuxDriver@microchip.com" , Andrew Lunn , "netdev@vger.kernel.org" , "devicetree@vger.kernel.org" , "linux-kernel@vger.kernel.org" , Thomas Petazzoni Subject: Re: [PATCH v2 3/6] net: ocelot: pre-compute injection frame header content Message-ID: <20211115115805.434e71a8@fixe.home> In-Reply-To: <20211115105144.le3a62a2wbkgp632@skbuf> References: <20211103091943.3878621-1-clement.leger@bootlin.com> <20211103091943.3878621-4-clement.leger@bootlin.com> <20211103123811.im5ua7kirogoltm7@skbuf> <20211103145351.793538c3@fixe.home> <20211115111344.03376026@fixe.home> <20211115105144.le3a62a2wbkgp632@skbuf> Organization: Bootlin X-Mailer: Claws Mail 3.18.0 (GTK+ 2.24.33; x86_64-pc-linux-gnu) MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8BIT Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Le Mon, 15 Nov 2021 10:51:45 +0000, Vladimir Oltean a écrit : > > I checked again my bandwith numbers (obtained with iperf3) with and > > without the pre-computed header: > > > > Test on standard packets with UDP (iperf3 -t 100 -l 1460 -u -b 0 -c *) > > - With pre-computed header: UDP TX: 33Mbit/s > > - Without UDP TX: 31Mbit/s > > -> 6.5% improvement > > > > Test on small packets with UDP (iperf3 -t 100 -l 700 -u -b 0 -c *) > > - With pre-computed header: UDP TX: 15.8Mbit/s > > - Without UDP TX: 16.4Mbit/s > > -> 4.3% improvement > > > > The improvement might not be huge but also not negligible at all. > > Please tell me if you want me to drop it or not based on those numbers. > > Is this with manual injection or with FDMA? Do you have before/after > numbers with FDMA as well? At 31 vs 33 Mbps, this isn't going to compete > for any races anyway :) These numbers were for the FDMA, with the CPU, its even much lower because more time is spent to push bytes through registers... But agreed with that, this isn't going to beat any records ! -- Clément Léger, Embedded Linux and Kernel engineer at Bootlin https://bootlin.com