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=-5.1 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,NICE_REPLY_A,SPF_HELO_NONE, SPF_PASS,USER_AGENT_SANE_1 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 B19F0C6379D for ; Mon, 16 Nov 2020 23:31:10 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 5C429216C4 for ; Mon, 16 Nov 2020 23:31:10 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="gLe5sdpb" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730115AbgKPXao (ORCPT ); Mon, 16 Nov 2020 18:30:44 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:44664 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726227AbgKPXan (ORCPT ); Mon, 16 Nov 2020 18:30:43 -0500 Received: from mail-pl1-x62c.google.com (mail-pl1-x62c.google.com [IPv6:2607:f8b0:4864:20::62c]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 45C58C0613CF; Mon, 16 Nov 2020 15:30:43 -0800 (PST) Received: by mail-pl1-x62c.google.com with SMTP id x15so9211472pll.2; Mon, 16 Nov 2020 15:30:43 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=subject:to:cc:references:from:autocrypt:message-id:date:user-agent :mime-version:in-reply-to:content-language:content-transfer-encoding; bh=7FYCGHJlYmaRXLMksd+6qbnneZmBkhJZIw7WgOI0UOE=; b=gLe5sdpbW/kH4E5quY1fIXqc69VvXGio3pk76cPJQz+Yr1lgoyk2rC0r6B2mDh8yJi L5+/1WxUvrov2xS8B93swbtjf1ZAe1ppKCs4UIxQ0UGGSinVgwwd1CE1L/B3DVosx1Zg suDbpRbMx766xUeCM6OIzCDWO7Y5voZc1D9I+QnnAxm8b0tjjBRaZNsEi5fHvS4jdqmL HBfFJ3VipsHlK3S2JxDOOBDVTXJxftuKSwBLxEAIJpgblNd6hhiGSRtKu3tD7TsAf+Uc IkPmXe76I9jHs1pw48swY1IAEcGPNPqcY0Gzva/alyHqymb4my4lM1LM9GPdUrQ4JtQW g2iw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:subject:to:cc:references:from:autocrypt :message-id:date:user-agent:mime-version:in-reply-to :content-language:content-transfer-encoding; bh=7FYCGHJlYmaRXLMksd+6qbnneZmBkhJZIw7WgOI0UOE=; b=ARtYkkUy7hVVuAz9GpT3rZzgt9HwLaWDZiHEfsiYcYYDd4MvM2ofqaKBeB+uIwUZhp JkC4lFGG2f7vfFtcBfk2yAXUw24t7zdls+N28cKhe2FoqEOyd9jn7DheRNdQvJtJyAhX bgejNbsTryt5H+7unBM1XuRTbsCZCaBE4WeWcFpq+ANJ29TWRXqXLmuEjM6cd8pSVJYD WXHKTiDAJzn9wk0gl+kuzoSNtRTXIQyrU5uO+v6v9yHZmSimwYr6QI/dTBtMtLr7Zu7J 85R5pyB9nxyTInsH6HN6UWz7at9sL770wMgPDCAiJVsiQkVIR31ADvByd2j79Mzo/yg/ rweA== X-Gm-Message-State: AOAM530fx4QV1z2DA/f5cknHGSg4g5hmPRBb+HDrm0gAx+vQYfQutn03 XZh47Bwmo11pfzRtEdxqodX01oaor3Q= X-Google-Smtp-Source: ABdhPJyTfEJWgc3iLOwXgR9mEU2BzDxOSpNx263Tui2bCHs5WAfmVAvAOLj5yTa5C+Vt+PwdkFPPQg== X-Received: by 2002:a17:902:ee85:b029:d6:c43e:2321 with SMTP id a5-20020a170902ee85b02900d6c43e2321mr14307430pld.29.1605569442171; Mon, 16 Nov 2020 15:30:42 -0800 (PST) Received: from [10.67.48.230] ([192.19.223.252]) by smtp.googlemail.com with ESMTPSA id y16sm19858944pfl.144.2020.11.16.15.30.40 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Mon, 16 Nov 2020 15:30:41 -0800 (PST) Subject: Re: [PATCH v1 net-next] net: dsa: qca: ar9331: add ethtool stats support To: Vladimir Oltean , Jakub Kicinski Cc: Oleksij Rempel , Andrew Lunn , Vivien Didelot , "David S. Miller" , Russell King , Pengutronix Kernel Team , netdev@vger.kernel.org, linux-kernel@vger.kernel.org, linux-mips@vger.kernel.org References: <20201115073533.1366-1-o.rempel@pengutronix.de> <20201116133453.270b8db5@kicinski-fedora-pc1c0hjn.dhcp.thefacebook.com> <20201116222146.znetv5u2q2q2vk2j@skbuf> <20201116143544.036baf58@kicinski-fedora-pc1c0hjn.dhcp.thefacebook.com> <20201116230053.ddub7p6lvvszz7ic@skbuf> <20201116151347.591925ca@kicinski-fedora-pc1c0hjn.dhcp.thefacebook.com> <20201116232731.4utpige7fguzghsi@skbuf> From: Florian Fainelli Autocrypt: addr=f.fainelli@gmail.com; prefer-encrypt=mutual; keydata= mQGiBEjPuBIRBACW9MxSJU9fvEOCTnRNqG/13rAGsj+vJqontvoDSNxRgmafP8d3nesnqPyR xGlkaOSDuu09rxuW+69Y2f1TzjFuGpBk4ysWOR85O2Nx8AJ6fYGCoeTbovrNlGT1M9obSFGQ X3IzRnWoqlfudjTO5TKoqkbOgpYqIo5n1QbEjCCwCwCg3DOH/4ug2AUUlcIT9/l3pGvoRJ0E AICDzi3l7pmC5IWn2n1mvP5247urtHFs/uusE827DDj3K8Upn2vYiOFMBhGsxAk6YKV6IP0d ZdWX6fqkJJlu9cSDvWtO1hXeHIfQIE/xcqvlRH783KrihLcsmnBqOiS6rJDO2x1eAgC8meAX SAgsrBhcgGl2Rl5gh/jkeA5ykwbxA/9u1eEuL70Qzt5APJmqVXR+kWvrqdBVPoUNy/tQ8mYc nzJJ63ng3tHhnwHXZOu8hL4nqwlYHRa9eeglXYhBqja4ZvIvCEqSmEukfivk+DlIgVoOAJbh qIWgvr3SIEuR6ayY3f5j0f2ejUMYlYYnKdiHXFlF9uXm1ELrb0YX4GMHz7QnRmxvcmlhbiBG YWluZWxsaSA8Zi5mYWluZWxsaUBnbWFpbC5jb20+iGYEExECACYCGyMGCwkIBwMCBBUCCAME FgIDAQIeAQIXgAUCVF/S8QUJHlwd3wAKCRBhV5kVtWN2DvCVAJ4u4/bPF4P3jxb4qEY8I2gS 6hG0gACffNWlqJ2T4wSSn+3o7CCZNd7SLSC5BA0ESM+4EhAQAL/o09boR9D3Vk1Tt7+gpYr3 WQ6hgYVON905q2ndEoA2J0dQxJNRw3snabHDDzQBAcqOvdi7YidfBVdKi0wxHhSuRBfuOppu pdXkb7zxuPQuSveCLqqZWRQ+Cc2QgF7SBqgznbe6Ngout5qXY5Dcagk9LqFNGhJQzUGHAsIs hap1f0B1PoUyUNeEInV98D8Xd/edM3mhO9nRpUXRK9Bvt4iEZUXGuVtZLT52nK6Wv2EZ1TiT OiqZlf1P+vxYLBx9eKmabPdm3yjalhY8yr1S1vL0gSA/C6W1o/TowdieF1rWN/MYHlkpyj9c Rpc281gAO0AP3V1G00YzBEdYyi0gaJbCEQnq8Vz1vDXFxHzyhgGz7umBsVKmYwZgA8DrrB0M oaP35wuGR3RJcaG30AnJpEDkBYHznI2apxdcuTPOHZyEilIRrBGzDwGtAhldzlBoBwE3Z3MY 31TOpACu1ZpNOMysZ6xiE35pWkwc0KYm4hJA5GFfmWSN6DniimW3pmdDIiw4Ifcx8b3mFrRO BbDIW13E51j9RjbO/nAaK9ndZ5LRO1B/8Fwat7bLzmsCiEXOJY7NNpIEpkoNoEUfCcZwmLrU +eOTPzaF6drw6ayewEi5yzPg3TAT6FV3oBsNg3xlwU0gPK3v6gYPX5w9+ovPZ1/qqNfOrbsE FRuiSVsZQ5s3AAMFD/9XjlnnVDh9GX/r/6hjmr4U9tEsM+VQXaVXqZuHKaSmojOLUCP/YVQo 7IiYaNssCS4FCPe4yrL4FJJfJAsbeyDykMN7wAnBcOkbZ9BPJPNCbqU6dowLOiy8AuTYQ48m vIyQ4Ijnb6GTrtxIUDQeOBNuQC/gyyx3nbL/lVlHbxr4tb6YkhkO6shjXhQh7nQb33FjGO4P WU11Nr9i/qoV8QCo12MQEo244RRA6VMud06y/E449rWZFSTwGqb0FS0seTcYNvxt8PB2izX+ HZA8SL54j479ubxhfuoTu5nXdtFYFj5Lj5x34LKPx7MpgAmj0H7SDhpFWF2FzcC1bjiW9mjW HaKaX23Awt97AqQZXegbfkJwX2Y53ufq8Np3e1542lh3/mpiGSilCsaTahEGrHK+lIusl6mz Joil+u3k01ofvJMK0ZdzGUZ/aPMZ16LofjFA+MNxWrZFrkYmiGdv+LG45zSlZyIvzSiG2lKy kuVag+IijCIom78P9jRtB1q1Q5lwZp2TLAJlz92DmFwBg1hyFzwDADjZ2nrDxKUiybXIgZp9 aU2d++ptEGCVJOfEW4qpWCCLPbOT7XBr+g/4H3qWbs3j/cDDq7LuVYIe+wchy/iXEJaQVeTC y5arMQorqTFWlEOgRA8OP47L9knl9i4xuR0euV6DChDrguup2aJVU4hPBBgRAgAPAhsMBQJU X9LxBQkeXB3fAAoJEGFXmRW1Y3YOj4UAn3nrFLPZekMeqX5aD/aq/dsbXSfyAKC45Go0YyxV HGuUuzv+GKZ6nsysJ7kCDQRXG8fwARAA6q/pqBi5PjHcOAUgk2/2LR5LjjesK50bCaD4JuNc YDhFR7Vs108diBtsho3w8WRd9viOqDrhLJTroVckkk74OY8r+3t1E0Dd4wHWHQZsAeUvOwDM PQMqTUBFuMi6ydzTZpFA2wBR9x6ofl8Ax+zaGBcFrRlQnhsuXLnM1uuvS39+pmzIjasZBP2H UPk5ifigXcpelKmj6iskP3c8QN6x6GjUSmYx+xUfs/GNVSU1XOZn61wgPDbgINJd/THGdqiO iJxCLuTMqlSsmh1+E1dSdfYkCb93R/0ZHvMKWlAx7MnaFgBfsG8FqNtZu3PCLfizyVYYjXbV WO1A23riZKqwrSJAATo5iTS65BuYxrFsFNPrf7TitM8E76BEBZk0OZBvZxMuOs6Z1qI8YKVK UrHVGFq3NbuPWCdRul9SX3VfOunr9Gv0GABnJ0ET+K7nspax0xqq7zgnM71QEaiaH17IFYGS sG34V7Wo3vyQzsk7qLf9Ajno0DhJ+VX43g8+AjxOMNVrGCt9RNXSBVpyv2AMTlWCdJ5KI6V4 KEzWM4HJm7QlNKE6RPoBxJVbSQLPd9St3h7mxLcne4l7NK9eNgNnneT7QZL8fL//s9K8Ns1W t60uQNYvbhKDG7+/yLcmJgjF74XkGvxCmTA1rW2bsUriM533nG9gAOUFQjURkwI8jvMAEQEA AYkCaAQYEQIACQUCVxvH8AIbAgIpCRBhV5kVtWN2DsFdIAQZAQIABgUCVxvH8AAKCRCH0Jac RAcHBIkHD/9nmfog7X2ZXMzL9ktT++7x+W/QBrSTCTmq8PK+69+INN1ZDOrY8uz6htfTLV9+ e2W6G8/7zIvODuHk7r+yQ585XbplgP0V5Xc8iBHdBgXbqnY5zBrcH+Q/oQ2STalEvaGHqNoD UGyLQ/fiKoLZTPMur57Fy1c9rTuKiSdMgnT0FPfWVDfpR2Ds0gpqWePlRuRGOoCln5GnREA/ 2MW2rWf+CO9kbIR+66j8b4RUJqIK3dWn9xbENh/aqxfonGTCZQ2zC4sLd25DQA4w1itPo+f5 V/SQxuhnlQkTOCdJ7b/mby/pNRz1lsLkjnXueLILj7gNjwTabZXYtL16z24qkDTI1x3g98R/ xunb3/fQwR8FY5/zRvXJq5us/nLvIvOmVwZFkwXc+AF+LSIajqQz9XbXeIP/BDjlBNXRZNdo dVuSU51ENcMcilPr2EUnqEAqeczsCGpnvRCLfVQeSZr2L9N4svNhhfPOEscYhhpHTh0VPyxI pPBNKq+byuYPMyk3nj814NKhImK0O4gTyCK9b+gZAVvQcYAXvSouCnTZeJRrNHJFTgTgu6E0 caxTGgc5zzQHeX67eMzrGomG3ZnIxmd1sAbgvJUDaD2GrYlulfwGWwWyTNbWRvMighVdPkSF 6XFgQaosWxkV0OELLy2N485YrTr2Uq64VKyxpncLh50e2RnyAJ9Za0Dx0yyp44iD1OvHtkEI M5kY0ACeNhCZJvZ5g4C2Lc9fcTHu8jxmEkI= Message-ID: <7cb26c4f-0c5d-0e08-5bbe-676f5d66a858@gmail.com> Date: Mon, 16 Nov 2020 15:30:39 -0800 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.10.0 MIME-Version: 1.0 In-Reply-To: <20201116232731.4utpige7fguzghsi@skbuf> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 11/16/20 3:27 PM, Vladimir Oltean wrote: > On Mon, Nov 16, 2020 at 03:13:47PM -0800, Jakub Kicinski wrote: >> On Tue, 17 Nov 2020 01:00:53 +0200 Vladimir Oltean wrote: >>> On Mon, Nov 16, 2020 at 02:35:44PM -0800, Jakub Kicinski wrote: >>>> On Tue, 17 Nov 2020 00:21:46 +0200 Vladimir Oltean wrote: >>>>> On Mon, Nov 16, 2020 at 01:34:53PM -0800, Jakub Kicinski wrote: >>>>>> You must expose relevant statistics via the normal get_stats64 NDO >>>>>> before you start dumping free form stuff in ethtool -S. >>>>> >>>>> Completely agree on the point, Jakub, but to be honest we don't give him >>>>> that possibility within the DSA framework today, see .ndo_get_stats64 in >>>>> net/dsa/slave.c which returns the generic dev_get_tstats64 implementation, >>>>> and not something that hooks into the hardware counters, or into the >>>>> driver at all, for that matter. >>>> >>>> Simple matter of coding, right? I don't see a problem. >>>> >>>> Also I only mentioned .ndo_get_stats64, but now we also have stats in >>>> ethtool->get_pause_stats. >>> >>> Yes, sure we can do that. The pause stats and packet counter ops would >>> need to be exposed to the drivers by DSA first, though. Not sure if this >>> is something you expect Oleksij to do or if we could pick that up separately >>> afterwards. >> >> Well, I feel like unless we draw the line nobody will have >> the incentive to do the work. >> >> I don't mind if it's Oleksij or anyone else doing the plumbing work, >> but the task itself seems rather trivial. > > So then I'll let Oleksij show his availability. > >>>>> But it's good that you raise the point, I was thinking too that we >>>>> should do better in terms of keeping the software counters in sync with >>>>> the hardware. But what would be a good reference for keeping statistics >>>>> on an offloaded interface? Is it ok to just populate the netdev counters >>>>> based on the hardware statistics? >>>> >>>> IIRC the stats on the interface should be a sum of forwarded in software >>>> and in hardware. Which in practice means interface HW stats are okay, >>>> given eventually both forwarding types end up in the HW interface >>>> (/MAC block). >>> >>> A sum? Wouldn't that count the packets sent/received by the stack twice? >> >> Note that I said _forwarded_. Frames are either forwarded by the HW or >> SW (former never hit the CPU, while the latter do hit the CPU or >> originate from it). > > Ah, you were just thinking out loud, I really did not understand what > you meant by the separation between "forwarded in software" and > "forwarded in hardware". > Yes, the hardware typically only gives us MAC-level counters anyway. > Another way to look at it is that the number of packets forwarded in > hardware from a given port are equal to the total number of RX packets > on that MAC minus the packets seen by the CPU coming from that port. > So all in all, it's the MAC-level counters we should expose in > .ndo_get_stats64, I'm glad you agree. As for the error packets, I > suppose that would be a driver-specific aggregate. > > What about RMON/RFC2819 style etherStatsPkts65to127Octets? We have a > number of switches supporting that style of counters, including the one > that Oleksij is adding support for, apparently (but not all switches > though). I suppose your M.O. is that anything standardizable is welcome > to be standardized via rtnetlink? > > Andrew, Florian, any opinions here? > Settling on RMON/RFC2819 statistics would work for me, and hopefully is not too hard to get the various drivers converted to. With respect to Oleksij's patch, I would tend to accept it so we actually have more visibility into what standardized counters are available across switch drivers. -- Florian