From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-qt0-f196.google.com ([209.85.216.196]:46651 "EHLO mail-qt0-f196.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1426315AbeCBOpp (ORCPT ); Fri, 2 Mar 2018 09:45:45 -0500 Received: by mail-qt0-f196.google.com with SMTP id m13so12088252qtg.13 for ; Fri, 02 Mar 2018 06:45:45 -0800 (PST) Date: Fri, 2 Mar 2018 11:45:39 -0300 From: Marcelo Ricardo Leitner To: Alexander Aring Cc: Jiri Pirko , Jakub Kicinski , netdev@vger.kernel.org, nogahf@mellanox.com, yuvalm@mellanox.com, David Miller , idosch@mellanox.com, mlxsw@mellanox.com, Jamal Hadi Salim , Cong Wang , kernel@mojatatu.com Subject: Re: [patch net-next 09/10] net: sch: prio: Add offload ability for grafting a child Message-ID: <20180302144539.GE3887@localhost.localdomain> References: <20180228094507.22354-1-jiri@resnulli.us> <20180228094507.22354-10-jiri@resnulli.us> <20180301194840.79a9a923@cakuba.netronome.com> <20180302083756.GE2099@nanopsycho> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Sender: netdev-owner@vger.kernel.org List-ID: On Fri, Mar 02, 2018 at 09:21:56AM -0500, Alexander Aring wrote: > Hi, > > On Fri, Mar 2, 2018 at 3:37 AM, Jiri Pirko wrote: > > Fri, Mar 02, 2018 at 04:48:40AM CET, kubakici@wp.pl wrote: > >>On Thu, 1 Mar 2018 22:38:50 -0500, Alexander Aring wrote: > >>> I guess to make extack working, you need to return an errno if failed. > >> > >>AFAIK extack is printed as a warning if operation did not fail. > > > > Yes, I checked this and it is printed as warning. > > ouch, so far I know extack it allows only one messages delivered back > to the user space. > > If we introduce a warning in the successful path here, it could be > that in the callpath (after "successful" part of this callback), that > somebody else want to add a warning and overwrites actually your > warning (even, he is not aware that this warning was set - okay I > suppose you can do another check on NULL and set a warning, that > somebody overwrites a warning :-D). > > If extack messages get's append and is some kind of for_each_nested > string in netlink -> we have no problem, but I guess this not how it's > working. :-/ IOW I guess what we are looking for here is a way to use extack to track more than an error/warning message, but to be a bit more complete error reporting tool. The case here is pretty much like the case with tc flower offloading, to issue a message when it couldn't offload while it wasn't fatal for the rule (in case SKIP_SW wasn't specified). The reason for why the offloading couldn't happen could have been a temporary one and such log of a warning is important for troubleshooting. Marcelo