Re: [dpdk-dev] [PATCH 2/3] net/mlx5: fix Direct Verbs flow tunnel

[Yongseok Koh <yskoh@mellanox.com>]

On Sun, Nov 04, 2018 at 01:22:34AM -0700, Ori Kam wrote:
> 
> > -----Original Message-----
> > From: Yongseok Koh
> > Sent: Friday, November 2, 2018 11:08 PM
> > To: Shahaf Shuler <shahafs@mellanox.com>
> > Cc: dev@dpdk.org; Yongseok Koh <yskoh@mellanox.com>; Ori Kam
> > <orika@mellanox.com>
> > Subject: [PATCH 2/3] net/mlx5: fix Direct Verbs flow tunnel
> > 
> > 1) Fix layer parsing
> > In translation of tunneled flows, dev_flow->layers must not be used to
> > check tunneled layer as it contains all the layers parsed from
> > flow_drv_prepare(). Checking tunneled layer is needed to distinguish
> > between outer and inner item. This should be based on dynamic parsing. With
> > dev_flow->layers on a tunneled flow, items will always be interpreted as
> > inner as dev_flow->layer already has all the items. Dynamic parsing
> > (item_flags) is added as there's no such code.
> > 
> > 2) Refactoring code
> > - flow_dv_create_item() and flow_dv_create_action() are merged into
> >   flow_dv_translate() for consistency with Verbs and *_validate().
> 
> I don't like the idea of combining 2 distinct functions into one.
> I think a function should be as short as possible and do only one thing,
> if there is no good reason why two functions should be combined they should not
> be combined.
> If you want to align both the Direct Verbs and  Verbs I think we can split the Verbs
> code.

Look at the other lengthy switch-case clauses in validate/prepare/translate in
each driver. This DV translate is the only exception. I'd rather like to ask
why. I didn't like the lengthy function from the beginning but you wanted to
keep it. Of course, I considered to split the Verbs one but that's the reason
why I chose to merge DV code. If we feel this lengthy func is really complex and
gets error prone, then we can refactor all the code at once later. Or, I still
prefer the graph approach. That would be simpler.

Thanks,
Yongseok