From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jiri Pirko Subject: Re: [PATCH net-next 2/2] flow_dissector: dissect tunnel info Date: Wed, 4 Oct 2017 10:15:58 +0200 Message-ID: <20171004081558.GE1895@nanopsycho> References: <1506933676-20121-1-git-send-email-simon.horman@netronome.com> <1506933676-20121-3-git-send-email-simon.horman@netronome.com> <20171003094052.GA20592@netronome.com> <20171004080856.GB6378@netronome.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: Tom Herbert , David Miller , Jiri Pirko , Jamal Hadi Salim , Cong Wang , Linux Kernel Network Developers , oss-drivers@netronome.com To: Simon Horman Return-path: Received: from mail-wr0-f176.google.com ([209.85.128.176]:48977 "EHLO mail-wr0-f176.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751249AbdJDIQA (ORCPT ); Wed, 4 Oct 2017 04:16:00 -0400 Received: by mail-wr0-f176.google.com with SMTP id u5so7890126wrc.5 for ; Wed, 04 Oct 2017 01:16:00 -0700 (PDT) Content-Disposition: inline In-Reply-To: <20171004080856.GB6378@netronome.com> Sender: netdev-owner@vger.kernel.org List-ID: Wed, Oct 04, 2017 at 10:08:57AM CEST, simon.horman@netronome.com wrote: >On Tue, Oct 03, 2017 at 11:17:46AM -0700, Tom Herbert wrote: >> On Tue, Oct 3, 2017 at 2:40 AM, Simon Horman wrote: >> > On Mon, Oct 02, 2017 at 01:37:55PM -0700, Tom Herbert wrote: >> >> On Mon, Oct 2, 2017 at 1:41 AM, Simon Horman wrote: >> >> > Move dissection of tunnel info from the flower classifier to the flow >> >> > dissector where all other dissection occurs. This should not have any >> >> > behavioural affect on other users of the flow dissector. >> > >> > ... >> >> > I feel that we are circling back the perennial issue of flower using the >> > flow dissector in a somewhat broader/different way than many/all other >> > users of the flow dissector. >> > >> Simon, >> >> It's more like __skb_flow_dissect is already an incredibly complex >> function and because of that it's difficult to maintain. We need to >> measure changes against that fact. For this patch, there is precisely >> one user (cls_flower.c) and it's not at all clear to me if there will >> be ever any more (e.g. for hashing we don't need tunnel info). IMO, it >> should be just as easy and less convolution for everyone to have >> flower call __skb_flow_dissect_tunnel_info directly and not call if >> from __skb_flow_dissect. > >Hi Tom, > >my original suggestion was just that, but Jiri indicated a strong preference >for the approach taken by this patch. I think we need to widen the >participants in this discussion. I like the __skb_flow_dissect to be the function to call and it will do the job according to the configuration. I don't like to split in multiple calls. Does not make sense in the most of the cases as the dissection state would have to be carried in between calls.