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 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 1ABD0C433FE for ; Wed, 29 Sep 2021 17:55:42 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id EBE8861506 for ; Wed, 29 Sep 2021 17:55:41 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1345386AbhI2R5V (ORCPT ); Wed, 29 Sep 2021 13:57:21 -0400 Received: from mail.kernel.org ([198.145.29.99]:48984 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1343675AbhI2R5V (ORCPT ); Wed, 29 Sep 2021 13:57:21 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 3F91561406; Wed, 29 Sep 2021 17:55:38 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1632938139; bh=Wdm5mZ9EIzamcCpNJ3f6wNkVlDGhsWErQpSRyqfdzvM=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=ScXxN8A83d1IhIwCquDkP/qeTHZqGJC3TLJ3FOxV2L1FoyPI6FHkUTH5yPMPNyPCU qXNzAifxJbHiPiO6nCkLMX7EPPaCyVhggywKQdGI6k8u/r+CShy6MDG1j6rLZglgcu igUym4bjnU1v9ZjB1vxlcRgu37WILOCSCsdSB7qn+EfYCWZE2anMLTjBSeGeEFXWkM 3EFSdkCUq1Todb5f+rX39drvyu8P8oZbA71z5YJJrjTkSrwr8bAk+DD5P0nKyaIpe8 CZpJTpp26nY4u4AUdYCrZiXjAbecEVDKi6gIbth+hYcnzqvJaDY5F6RZD0/6MUJuBl Z889Vw81JzPKg== Date: Wed, 29 Sep 2021 10:55:37 -0700 From: Jakub Kicinski To: Leon Romanovsky Cc: "David S . Miller" , Alexandre Belloni , Andrew Lunn , Ariel Elior , Bin Luo , Claudiu Manoil , Coiby Xu , Derek Chickles , drivers@pensando.io, Eric Dumazet , Felix Manlunas , Florian Fainelli , Geetha sowjanya , Greg Kroah-Hartman , GR-everest-linux-l2@marvell.com, GR-Linux-NIC-Dev@marvell.com, hariprasad , Ido Schimmel , intel-wired-lan@lists.osuosl.org, Ioana Ciornei , Jerin Jacob , Jesse Brandeburg , Jiri Pirko , Jonathan Lemon , Linu Cherian , linux-kernel@vger.kernel.org, linux-omap@vger.kernel.org, linux-rdma@vger.kernel.org, linux-staging@lists.linux.dev, Manish Chopra , Michael Chan , Moshe Shemesh , netdev@vger.kernel.org, oss-drivers@corigine.com, Richard Cochran , Saeed Mahameed , Salil Mehta , Satanand Burla , Shannon Nelson , Shay Drory , Simon Horman , Subbaraya Sundeep , Sunil Goutham , Taras Chornyi , Tariq Toukan , Tony Nguyen , UNGLinuxDriver@microchip.com, Vadym Kochan , Vivien Didelot , Vladimir Oltean , Yisen Zhuang Subject: Re: [PATCH net-next v1 0/5] Devlink reload and missed notifications fix Message-ID: <20210929105537.758d5d85@kicinski-fedora-pc1c0hjn.dhcp.thefacebook.com> In-Reply-To: References: <20210929064004.3172946e@kicinski-fedora-pc1c0hjn.dhcp.thefacebook.com> <20210929073940.5d7ed022@kicinski-fedora-pc1c0hjn.dhcp.thefacebook.com> MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-rdma@vger.kernel.org On Wed, 29 Sep 2021 18:31:51 +0300 Leon Romanovsky wrote: > On Wed, Sep 29, 2021 at 07:39:40AM -0700, Jakub Kicinski wrote: > > On Wed, 29 Sep 2021 17:13:28 +0300 Leon Romanovsky wrote: > > > We don't need to advertise counters for feature that is not supported. > > > In multiport mlx5 devices, the reload functionality is not supported, so > > > this change at least make that device to behave like all other netdev > > > devices that don't support devlink reload. > > > > > > The ops structure is set very early to make sure that internal devlink > > > routines will be able access driver back during initialization (btw very > > > questionable design choice) > > > > Indeed, is this fixable? Or now that devlink_register() was moved to > > the end of probe netdev can call ops before instance is registered? > > > > > and at that stage the driver doesn't know > > > yet which device type it is going to drive. > > > > > > So the answer is: > > > 1. Can't have two structures. > > > > I still don't understand why. To be clear - swapping full op structures > > is probably acceptable if it's a pure upgrade (existing pointers match). > > Poking new ops into a structure (in alphabetical order if I understand > > your reply to Greg, not destructor-before-contructor) is what I deem > > questionable. > > It is sorted simply for readability and not for any other technical > reason. > > Regarding new ops, this is how we are setting callbacks in RDMA based on > actual device support. It works like a charm. > > > > 2. Same behaviour across all netdev devices. > > > > Unclear what this is referring to. > > If your device doesn't support devlink reload, it won't print any > reload counters at all. It is not the case for the multiport mlx5 > device. It doesn't support, but still present these counters. There's myriad ways you can hide features. Swapping ops is heavy handed and prone to data races, I don't like it.