Re: [patch net-next] tc: introduce OpenFlow classifier

[Jiri Pirko <jiri@resnulli.us>]

Fri, Mar 27, 2015 at 01:36:27PM CET, tgraf@suug.ch wrote:
>On 03/27/15 at 01:28pm, Jiri Pirko wrote:
>> Fri, Mar 27, 2015 at 12:44:02PM CET, tgraf@suug.ch wrote:
>> >On 03/27/15 at 07:07am, Jiri Pirko wrote:
>> >> well, you can do *everything* with cls_bpf now that it supports ebpf.
>> >> But I think it is a big hammer. cls_openflow suppose to be just
>> >> replacement for existing ovs classification, with very simple and well
>> >> understood uapi.
>> >
>> >The current linear filtering approach makes it not suitable
>> >right now. No doubt that unifying flow classification would
>> >be great to have.
>> >
>> >Once you start building some form of wildcarded hash tables
>> >into this, I see a lot of overlap with cls_flow appearing.
>> >What about extending cls_flow instead? Are you still planning
>> >to have one cls_classifier instance per wildcard flow?
>> 
>> I'm not fan of extending cls_flow. It does something else. It calculates
>> hash and set classid according to that. I like better to do cls_openflow
>> on side.
>
>You'll probably end up with a hash as well. I doubt that you
>want to walk through a linear list of matches in the long term.
>Not sure about your plans though.

Sure, that was supposed next step, to change this to hash list.

>
>> >I'm usually all for small steps and take it from there but you
>> >are setting a uapi in stone here and once you add linear
>> >filtering behaviour you can't just undo it without a ton of
>> >flags.
>> 
>> 
>> Sure, what exactly is your uapi change proposal? I'd be glad to
>> incorporate it.
>
>You are adding linear matching with first-add-first-match
>behaviour. You can't break this order guarantee afterwards.

Allright.  I'll reimplement that.