Wed, Oct 04, 2017 at 09:07:17PM CEST, simon.hor...@netronome.com wrote: >On Wed, Oct 04, 2017 at 08:07:15PM +0200, Jiri Pirko wrote: >> Wed, Oct 04, 2017 at 05:52:54PM CEST, t...@herbertland.com wrote: >> >On Wed, Oct 4, 2017 at 1:15 AM, Jiri Pirko <j...@resnulli.us> wrote: >> >> Wed, Oct 04, 2017 at 10:08:57AM CEST, simon.hor...@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 >> >>>> <simon.hor...@netronome.com> 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 >> >>>> >> <simon.hor...@netronome.com> 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. >> > >> >Those are not technical arguments. As I already mentioned, I don't >> >like it when we add stuff for the benefit of a 1% use case that >> >negatively impacts the rest of the 99% cases which is what I believe >> >is happening here. >> >> Yeah. I just wanted the flow dissector to stay compact. But if needed, >> could be split. I just fear that it will become a mess that's all. >> >> >> > >> >> Does not make sense in the most of the cases as the >> >> dissection state would have to be carried in between calls. >> > >> >Please elaborate. This code is being moved into __skb_flow_dissect, so >> >the functionality was already there. I don't see any description in >> >this discussion that things were broken and that this patch is a >> >necessary fix. >> >> Yeah, you are right. > >Hi Tom, Hi Jiri, > >I'm happy to make a patch to move the call to >__skb_flow_dissect_tunnel_info() from __skb_flow_dissect() to >fl_classify(). It seems that approach has been agreed on above.
If the consensus is that the right way is to cut-out flow dissector, so be it. But first, I believe it is reasonable to request to see some numbers that would indicate that it actually resolves anything.
