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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 0BA80C678DA for ; Thu, 12 Jan 2023 20:06:54 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S237088AbjALUGu (ORCPT ); Thu, 12 Jan 2023 15:06:50 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:44346 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S239706AbjALT7W (ORCPT ); Thu, 12 Jan 2023 14:59:22 -0500 Received: from ams.source.kernel.org (ams.source.kernel.org [145.40.68.75]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 0EF9238A1 for ; Thu, 12 Jan 2023 11:59:06 -0800 (PST) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ams.source.kernel.org (Postfix) with ESMTPS id BD737B81E5F for ; Thu, 12 Jan 2023 19:59:04 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 96D6FC4339B; Thu, 12 Jan 2023 19:59:02 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1673553543; bh=89zvIK/2JcZrndkW3y9+dlieAuFcvu2Gm+arpmVwGzM=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=DRUDqg2VagHDjQfLWi/x11dCu8e9XCgZuEu4UTrCsqLW683rzvE4rrrHZ68GxHuDy O8RF+MZ7bftl3JFrEmbrgu1S6DxogA+XVvl0BQa8OJZK+FIXCgGbrQNAIDq99EK4cH 9aRsCHH48DkYaoNxQwr00r7UagSqgS2pup0ygroIbgeU8XWqvViB1j7f0YrRuZzZnc uSifRmfZb6Lxhkgg3od7L4J9QB+lVw5llfRL/ox6nvIl/SuItafUsO6PAK9es7EyXv UdqVmG/z//APqqvWhsRUb3uFeyQUtBWWVz4AsSYLJrWm9XqgS4lraC8NV3aRcMrqN4 VlFgqCFyRsCJg== Date: Thu, 12 Jan 2023 21:58:58 +0200 From: Leon Romanovsky To: Jiri Pirko Cc: Jacob Keller , Jakub Kicinski , davem@davemloft.net, netdev@vger.kernel.org, edumazet@google.com, pabeni@redhat.com Subject: Re: [PATCH net-next 7/9] devlink: allow registering parameters after the instance Message-ID: References: <20230106132251.29565214@kernel.org> <14cdb494-1823-607a-2952-3c316a9f1212@intel.com> <20230110122222.57b0b70e@kernel.org> <20230111084549.258b32fb@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org On Thu, Jan 12, 2023 at 03:59:53PM +0100, Jiri Pirko wrote: > Thu, Jan 12, 2023 at 08:07:43AM CET, leon@kernel.org wrote: > >On Wed, Jan 11, 2023 at 01:29:03PM -0800, Jacob Keller wrote: > >> > >> > >> On 1/11/2023 8:45 AM, Jakub Kicinski wrote: > >> > On Wed, 11 Jan 2023 10:32:13 +0100 Jiri Pirko wrote: > >> >>>> I'm confused. You want to register objects after instance register? > >> >>> > >> >>> +1, I think it's an anti-pattern. > >> >> > >> >> Could you elaborate a bit please? > >> > > >> > Mixing registering sub-objects before and after the instance is a bit > >> > of an anti-pattern. Easy to introduce bugs during reload and reset / > >> > error recovery. I thought that's what you were saying as well. > >> > >> I was thinking of a case where an object is dynamic and might get added > >> based on events occurring after the devlink was registered. > >> > >> But the more I think about it the less that makes sense. What events > >> would cause a whole subobject to be registerd which we wouldn't already > >> know about during initialization of devlink? > >> > >> We do need some dynamic support because situations like "add port" will > >> add a port and then the ports subresources after the main devlink, but I > >> think that is already supported well and we'd add the port sub-resources > >> at the same time as the port. > >> > >> But thinking more on this, there isn't really another good example since > >> we'd register things like health reporters, regions, resources, etc all > >> during initialization. Each of these sub objects may have dynamic > >> portions (ex: region captures, health events, etc) but the need for the > >> object should be known about during init time if its supported by the > >> device driver. > > > >As a user, I don't want to see any late dynamic object addition which is > >not triggered by me explicitly. As it doesn't make any sense to add > >various delays per-vendor/kernel in configuration scripts just because > >not everything is ready. Users need predictability, lazy addition of > >objects adds chaos instead. > > > >Agree with Jakub, it is anti-pattern. > > Yeah, but, we have reload. And during reload, instance is still > registered yet the subobject disappear and reappear. So that would be > inconsistent with the init/fini flow. > > Perhaps during reload we should emulate complete fini/init notification > flow to the user? "reload" is triggered by me explicitly and I will get success/fail result at the end. There is no much meaning in subobject notifications during that operation. Thanks