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=-6.7 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,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 3FE6BC432BE for ; Tue, 3 Aug 2021 23:57:28 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 258DD60F94 for ; Tue, 3 Aug 2021 23:57:28 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234755AbhHCX5i (ORCPT ); Tue, 3 Aug 2021 19:57:38 -0400 Received: from mail.kernel.org ([198.145.29.99]:45720 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233734AbhHCX5h (ORCPT ); Tue, 3 Aug 2021 19:57:37 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 2456860F45; Tue, 3 Aug 2021 23:57:23 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1628035045; bh=Y98IZD9r0/9I1bvy4BdIP6VjyzQFWfmsVGhrrmzDDRc=; h=Subject:From:To:Cc:Date:In-Reply-To:References:From; b=r31R5ozKzXHyvIH6vCt4dFW1dv/yowBvBlNe0KTqPOgL9f2iAoLsADk8OBJoHQzzG re8mfCOcR98uGWtgR2d0bWL9NRsh7meVM1K8UxNVyOCcFsSVzcSFhmjqXv5lfbNgE5 f99a0+pOLjywwdSZ/xOYBRO5pIOjjwFGTWbPZnd7Mfs0wy54vrj2x7kBjHjGgfgdQP 0BjY0uAlswD8YNHjKi6eB8DvFFujpYgrQ3R3DNUXJfBhyhN9i7u5Amxh1ybDmOLuop zNJs1ef7vqjrE/7aJ1O+hp0Ree3wEXio1PzHbz41oWoLc9wmfYNBuJeB81guBTbE2t EipEQYo6grupA== Message-ID: Subject: Re: [PATCH net-next 03/21] ethtool, stats: introduce standard XDP statistics From: Saeed Mahameed To: Jakub Kicinski , Alexander Lobakin Cc: "David S. Miller" , Jesse Brandeburg , Lukasz Czapnik , Marcin Kubiak , Michal Kubiak , Michal Swiatkowski , Jonathan Corbet , Netanel Belgazal , Arthur Kiyanovski , Guy Tzalik , Saeed Bishara , Ioana Ciornei , Claudiu Manoil , Thomas Petazzoni , Marcin Wojtas , Russell King , Edward Cree , Martin Habets , "Michael S. Tsirkin" , Jason Wang , Alexei Starovoitov , Daniel Borkmann , Jesper Dangaard Brouer , John Fastabend , Andrii Nakryiko , Martin KaFai Lau , Song Liu , Yonghong Song , KP Singh , Shay Agroskin , Sameeh Jubran , Alexander Duyck , Danielle Ratson , Ido Schimmel , Andrew Lunn , Vladyslav Tarasiuk , Arnd Bergmann , Andrew Morton , Jian Shen , Petr Vorel , Dan Murphy , Yangbo Lu , Michal Kubecek , Zheng Yongjun , Heiner Kallweit , YueHaibing , Johannes Berg , netdev@vger.kernel.org, linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, virtualization@lists.linux-foundation.org, bpf@vger.kernel.org Date: Tue, 03 Aug 2021 16:57:22 -0700 In-Reply-To: <20210803134900.578b4c37@kicinski-fedora-pc1c0hjn.dhcp.thefacebook.com> References: <20210803163641.3743-1-alexandr.lobakin@intel.com> <20210803163641.3743-4-alexandr.lobakin@intel.com> <20210803134900.578b4c37@kicinski-fedora-pc1c0hjn.dhcp.thefacebook.com> Content-Type: text/plain; charset="UTF-8" User-Agent: Evolution 3.40.3 (3.40.3-1.fc34) MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org On Tue, 2021-08-03 at 13:49 -0700, Jakub Kicinski wrote: > On Tue,  3 Aug 2021 18:36:23 +0200 Alexander Lobakin wrote: > > Most of the driver-side XDP enabled drivers provide some statistics > > on XDP programs runs and different actions taken (number of passes, > > drops, redirects etc.). > > Could you please share the statistics to back that statement up? > Having uAPI for XDP stats is pretty much making the recommendation > that drivers should implement such stats. The recommendation from > Alexei and others back in the day (IIRC) was that XDP programs should > implement stats, not the drivers, to avoid duplication. > There are stats "mainly errors*" that are not even visible or reported to the user prog, for that i had an idea in the past to attach an exception_bpf_prog provided by the user, where driver/stack will report errors to this special exception_prog. > > Regarding that it's almost pretty the same across all the drivers > > (which is obvious), we can implement some sort of "standardized" > > statistics using Ethtool standard stats infra to eliminate a lot > > of code and stringsets duplication, different approaches to count > > these stats and so on. > > I'm not 100% sold on the fact that these should be ethtool stats. > Why not rtnl_fill_statsinfo() stats? Current ethtool std stats are > all pretty Ethernet specific, and all HW stats. Mixing HW and SW > stats > is what we're trying to get away from. > XDP is going to always be eBPF based ! why not just report such stats to a special BPF_MAP ? BPF stack can collect the stats from the driver and report them to this special MAP upon user request. > > These new 12 fields provided by the standard XDP stats should cover > > most, if not all, stats that might be interesting for collecting > > and > > tracking. > > Note that most NIC drivers keep XDP statistics on a per-channel > > basis, so this also introduces a new callback for getting a number > > of channels which a driver will provide stats for. If it's not > > implemented or returns 0, it means stats are global/device-wide. > > Per-channel stats via std ethtool stats are not a good idea. Per > queue > stats must be via the queue netlink interface we keep talking about > for > ever but which doesn't seem to materialize. When stats are reported > via > a different interface than objects they pertain to matching stats, > objects and their lifetime becomes very murky.