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=-8.0 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 653E2C433E1 for ; Wed, 19 Aug 2020 02:43:32 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 3E75620639 for ; Wed, 19 Aug 2020 02:43:32 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="cFO+vLfp" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727780AbgHSCnb (ORCPT ); Tue, 18 Aug 2020 22:43:31 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:53994 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726982AbgHSCna (ORCPT ); Tue, 18 Aug 2020 22:43:30 -0400 Received: from mail-oi1-x244.google.com (mail-oi1-x244.google.com [IPv6:2607:f8b0:4864:20::244]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 54059C061389 for ; Tue, 18 Aug 2020 19:43:29 -0700 (PDT) Received: by mail-oi1-x244.google.com with SMTP id u63so19794434oie.5 for ; Tue, 18 Aug 2020 19:43:29 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=subject:to:cc:references:from:message-id:date:user-agent :mime-version:in-reply-to:content-language:content-transfer-encoding; bh=0V84eV3PsOfzNuhmGWZMkvchC2vPimAKhWK3tiGYf0o=; b=cFO+vLfp44H2vCA+DLx+JMMuGox7XfNDKVxKxQ5iitTyZCR/ahcQmGRQC0wfTexh9p ckyGXNeZT8jMl7eVBrvDYhUzVSV+nmdknU26nJd6s1vzy4amcdZoLSsItK5uELu8u5zr fVx9x0xtJZUYCbbcXS1MN+1B+26uM3ojwxnEv3UIIqL9jvQ/IqzaE4ao1xBQkMrjk/wP Gbk2/Lz7jwY166aNopiINpfQtjZ6F0YtvMoJBswuZygGxUWm95rGGF7rVgm66za6ON6Y YRqzQgUVFweU4xHCG1uv5TJTjZNTlO/w3KkCb0xx/xrJXS7If3f4X33DxCLI+g7IHwqb RPGg== 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:message-id:date :user-agent:mime-version:in-reply-to:content-language :content-transfer-encoding; bh=0V84eV3PsOfzNuhmGWZMkvchC2vPimAKhWK3tiGYf0o=; b=JumGo718HH0GtwSoDNhg98lVtL1u4yTIKuvOrsP/SMqESWiqt/jpO7lE2BOETr4Ifd Csb2wKCK7cEACcWYOjgEsHf19+N7V7lCHWZbx8IeFeqaEq9Od1IJUardh3HMPeWXxIik rsFPvRIWcQh0SKvSNKylD7h8zE3ImHB9xDylX4qCPjWrebPpQdGALEATZmAfcCPEc4lj KqTLoWfniFSjNcA8VqfpEa2FjEjADwHQPayh2L/bd3HL2Up6RCXdf6WmYu5R7iOHU7Gm zqBi3lPObmKNRYMpW4MwNK10vnTYXdI5I4BGsbh+Iz0oGHSrZPq2eUqa9MXpHTOlwE6j SMyA== X-Gm-Message-State: AOAM533MEc1SQgdlkJP6rPN4wpk6LihQm5vjZYvuXu1FhWRRQoOBIhE3 +iAAiIdotYQ4hRUL7bk4Iu0= X-Google-Smtp-Source: ABdhPJz8yWsln61cE4xBWZIqqJ57DOsqtCRT3ruJai6redskYEzFeVcltXfEWx+DIwuljPJ3yMG/4g== X-Received: by 2002:aca:c5d6:: with SMTP id v205mr2035605oif.143.1597805008281; Tue, 18 Aug 2020 19:43:28 -0700 (PDT) Received: from Davids-MacBook-Pro.local ([2601:282:803:7700:ed5e:5850:8cad:6cb]) by smtp.googlemail.com with ESMTPSA id u20sm4524377ots.0.2020.08.18.19.43.26 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Tue, 18 Aug 2020 19:43:27 -0700 (PDT) Subject: Re: [RFC PATCH net-next 0/6] devlink: Add device metric support To: Jakub Kicinski , Ido Schimmel Cc: netdev@vger.kernel.org, davem@davemloft.net, jiri@nvidia.com, amcohen@nvidia.com, danieller@nvidia.com, mlxsw@nvidia.com, roopa@nvidia.com, andrew@lunn.ch, f.fainelli@gmail.com, vivien.didelot@gmail.com, saeedm@nvidia.com, tariqt@nvidia.com, ayal@nvidia.com, eranbe@nvidia.com, mkubecek@suse.cz, Ido Schimmel References: <20200817125059.193242-1-idosch@idosch.org> <20200818172419.5b86801b@kicinski-fedora-pc1c0hjn.dhcp.thefacebook.com> From: David Ahern Message-ID: <58a0356d-3e15-f805-ae52-dc44f265661d@gmail.com> Date: Tue, 18 Aug 2020 20:43:11 -0600 User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.15; rv:68.0) Gecko/20100101 Thunderbird/68.11.0 MIME-Version: 1.0 In-Reply-To: <20200818172419.5b86801b@kicinski-fedora-pc1c0hjn.dhcp.thefacebook.com> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org On 8/18/20 6:24 PM, Jakub Kicinski wrote: > On Mon, 17 Aug 2020 15:50:53 +0300 Ido Schimmel wrote: >> From: Ido Schimmel >> >> This patch set extends devlink to allow device drivers to expose device >> metrics to user space in a standard and extensible fashion, as opposed >> to the driver-specific debugfs approach. > > I feel like all those loose hardware interfaces are a huge maintenance > burden. I don't know what the solution is, but the status quo is not > great. I don't agree with the 'loose' characterization. Ido and team are pushing what is arguably a modern version of `ethtool -S`, so it provides a better API for retrieving data. > > I spend way too much time patrolling ethtool -S outputs already. > But that's the nature of detailed stats which are often essential to ensuring the system is operating as expected or debugging some problem. Commonality is certainly desired in names when relevant to be able to build tooling around the stats. As an example, per-queue stats have been essential to me for recent investigations. ethq has been really helpful in crossing NIC vendors and viewing those stats as it handles the per-vendor naming differences, but it requires changes to show anything else - errors per queue, xdp stats, drops, etc. This part could be simpler. As for this set, I believe the metrics exposed here are more unique to switch ASICs. At least one company I know of has built a business model around exposing detailed telemetry of switch ASICs, so clearly some find them quite valuable.