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 A8FB4C54EBE for ; Mon, 16 Jan 2023 11:25:20 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229725AbjAPLZT (ORCPT ); Mon, 16 Jan 2023 06:25:19 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:50510 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229553AbjAPLZS (ORCPT ); Mon, 16 Jan 2023 06:25:18 -0500 Received: from ams.source.kernel.org (ams.source.kernel.org [IPv6:2604:1380:4601:e00::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id A4FE81DB99 for ; Mon, 16 Jan 2023 03:25:17 -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 5B52DB80E59 for ; Mon, 16 Jan 2023 11:25:16 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id BE862C433EF; Mon, 16 Jan 2023 11:25:13 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1673868315; bh=EiLwQcjX0WGBq7/8/0LFZXRHhMC6vnz9O4+0U2bSa5Y=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=q279AOnC2558QQW7vnUY0XwA1j20PRQR4mds1wxupOCAi1q0s0gmv8iM68gnT4ynp eKwhE+0DDfjScuzkHBy0lfQ28XJ0JvD6/iZQIr+CHkqFp9MMLUSeuaB5oRR9uU34m3 8aR1gOgvtBzlNFRwVpugjAdkPZ0EifaPOvgzM18tNdyvjjsYoFFzWWR1um9u67rMlF /HraNrZiv32KIz26GcAW2fGJcNpKYNQb+7Tt6Vay5nz9FgwwatiBuRGTav9fj89xKe uJLEdlUUDmiaxlEAsDZHCnAxBJaVdMot4YBl9tLr6fOKGfvURuK/kgowYlL0RVo9xe WUlBiVGAIRx7g== Date: Mon, 16 Jan 2023 13:25:08 +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: <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 Mon, Jan 16, 2023 at 11:33:05AM +0100, Jiri Pirko wrote: > Sun, Jan 15, 2023 at 09:35:57AM CET, leon@kernel.org wrote: > >On Fri, Jan 13, 2023 at 08:50:33AM +0100, Jiri Pirko wrote: > >> Thu, Jan 12, 2023 at 08:58:58PM CET, leon@kernel.org wrote: > >> >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. > >> > >> Definitelly not. User would trigger reload, however another entity > >> (systemd for example) would listen to the notifications and react > >> if necessary. > > > >Listen yes, however it is not clear if notification sequence should > >mimic fini/init flow. > > Well, it makes sense to me. Why do you think it should not? After all this years, I still don't understand the mandate of devlink reload. It doesn't load/unload driver completely and as such not really performs probe/remove sequences. There is no requirement from the driver to do anything even close to fini/init too. Sometimes, devlink reload behaves as fini/init, but not always. This is why I'm not sure. Thanks > > > > >Thanks > > > >> > >> > > >> >Thanks