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=-6.6 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY,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 0C25CC63697 for ; Sat, 14 Nov 2020 19:17:48 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id C2CAE22265 for ; Sat, 14 Nov 2020 19:17:47 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="Gr428jHh" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726340AbgKNTR1 (ORCPT ); Sat, 14 Nov 2020 14:17:27 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:43536 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726112AbgKNTR0 (ORCPT ); Sat, 14 Nov 2020 14:17:26 -0500 Received: from mail-ej1-x644.google.com (mail-ej1-x644.google.com [IPv6:2a00:1450:4864:20::644]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 1A86AC0613D1; Sat, 14 Nov 2020 11:17:26 -0800 (PST) Received: by mail-ej1-x644.google.com with SMTP id o21so18674083ejb.3; Sat, 14 Nov 2020 11:17:26 -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; bh=DbC8+y4b+eAA7rNyPLQIjCBTvRwcIcXayWyHs45xBpo=; b=Gr428jHhlSJ1UhxNAedZ0/zlY4OdkyeF77gcdE2s2a4pJaA7nRFTlKfhQcmKWUupGl lhgGJvJhFwic5BUYeRCgzpqD9RlmtBWcY+plCxSaa11r53EoCky2XLP+8/gNC4lCeC4X 0JEbRHsvcZEDIgwQMyga8so7CvJD1NYvhthNbizHH/hVvahHwwqYzTrLS1yIRYl5jou0 l6p2l+A0h5WyG1yCBH8X6pC4eos+Na81axmkrNogJ+CChi6UqyHu4rvEk/ZEmmtQ+9cM EkVFvk93DklAJst75aOTZcm/MplGoAcTcstrSvHOuIb6wEYlqH1apMzcgZnedIL+TMzt BE7Q== 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; bh=DbC8+y4b+eAA7rNyPLQIjCBTvRwcIcXayWyHs45xBpo=; b=dthJvvVCO+Ba79ouZ2jsDkboIgZHC0iexkhaL8Qd2urZgI/qqkBHPDX8B3mAwdWsZJ kQImbAms2QqXkZmpF7Zx7XB18kmlgbOJpU5bqAuHW79j2utKiSb2MsXu+MvAT4kWY3JE 4goibftG6dNo0uFaBJvOBn28k1yBNWHe+5SfoJuRUtvdwc8SYnf1ch1djBN/4HGeaHRa OEsnJ7KUg5LAS4WYAqZ9pPYnu4gIRZ9JvVJaboUYTcLjPicoMizAk7KbUZzIxkVhC/B4 SbXwfwfmg0l8Dr0hYwGxLcRu3/gbMQ2LPN+ZQIbw1yT4PWOE8NVi4dD26eWefbTAFJVz hyTg== X-Gm-Message-State: AOAM532Ri2Cf/cSt8jFSibP2O4SBYtZi8hFYTvKPOSNrEamZN4B/Q5/R rmCEGbc3hbZ9h5zdOpFQORYKJk9dOHk= X-Google-Smtp-Source: ABdhPJyaXjIdNFAbFCAsA0fR9h5dQCJAEvzN16slQB8P+tn2EJ+nAhIuiG7YUwK1Z70qlGJIOfrLUg== X-Received: by 2002:a17:906:860b:: with SMTP id o11mr694528ejx.252.1605381444693; Sat, 14 Nov 2020 11:17:24 -0800 (PST) Received: from skbuf ([188.25.2.177]) by smtp.gmail.com with ESMTPSA id b1sm7327231ejg.60.2020.11.14.11.17.23 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Sat, 14 Nov 2020 11:17:24 -0800 (PST) Date: Sat, 14 Nov 2020 21:17:23 +0200 From: Vladimir Oltean To: Grygorii Strashko Cc: "David S. Miller" , netdev@vger.kernel.org, Jakub Kicinski , Vignesh Raghavendra , Sekhar Nori , linux-kernel@vger.kernel.org, linux-omap@vger.kernel.org, Tony Lindgren Subject: Re: [PATCH net-next 3/3] net: ethernet: ti: am65-cpsw: enable broadcast/multicast rate limit support Message-ID: <20201114191723.rvmhyrqinkhdjtpr@skbuf> References: <20201114035654.32658-1-grygorii.strashko@ti.com> <20201114035654.32658-4-grygorii.strashko@ti.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20201114035654.32658-4-grygorii.strashko@ti.com> Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org On Sat, Nov 14, 2020 at 05:56:54AM +0200, Grygorii Strashko wrote: > This patch enables support for ingress broadcast(BC)/multicast(MC) rate limiting > in TI AM65x CPSW driver (the corresponding ALE support was added in previous > patch) by implementing HW offload for simple tc-flower policer with matches > on dst_mac: > - ff:ff:ff:ff:ff:ff has to be used for BC rate limiting > - 01:00:00:00:00:00 fixed value has to be used for MC rate limiting > > Hence tc policer defines rate limit in terms of bits per second, but the > ALE supports limiting in terms of packets per second - the rate limit > bits/sec is converted to number of packets per second assuming minimum > Ethernet packet size ETH_ZLEN=60 bytes. > > Examples: > - BC rate limit to 1000pps: > tc qdisc add dev eth0 clsact > tc filter add dev eth0 ingress flower skip_sw dst_mac ff:ff:ff:ff:ff:ff \ > action police rate 480kbit burst 64k > > rate 480kbit - 1000pps * 60 bytes * 8, burst - not used. > > - MC rate limit to 20000pps: > tc qdisc add dev eth0 clsact > tc filter add dev eth0 ingress flower skip_sw dst_mac 01:00:00:00:00:00 \ > action police rate 9600kbit burst 64k > > rate 9600kbit - 20000pps * 60 bytes * 8, burst - not used. > > Signed-off-by: Grygorii Strashko > --- I understand this is unpleasant feedback, but don't you want to extend tc-police to have an option to rate-limit based on packet count and not based on byte count? The assumption you make in the driver that the packets are all going to be minimum-sized is not a great one. I can imagine that the user's policer budget is vastly exceeded if they enable jumbo frames and they put a policer at 9.6 Mbps, and this is not at all according to their expectation. 20Kpps assuming 60 bytes per packet might be 9.6 Mbps, and the user will assume this bandwidth profile is not exceeded, that's the whole point. But 20Kpps assuming 9KB per packet is 1.44Gbps. Weird.