RE: [PATCH v3] ethdev: deprecate header fields and metadata flow actions

[Slava Ovsiienko <viacheslavo@nvidia.com>]

> -----Original Message-----
> From: Ferruh Yigit <ferruh.yigit@intel.com>
> Sent: Thursday, November 25, 2021 16:41
> To: Slava Ovsiienko <viacheslavo@nvidia.com>; NBU-Contact-Thomas
> Monjalon (EXTERNAL) <thomas@monjalon.net>; Andrew Rybchenko
> <andrew.rybchenko@oktetlabs.ru>; Ajit Khaparde
> <ajit.khaparde@broadcom.com>; Somnath Kotur
> <somnath.kotur@broadcom.com>; Rahul Lakkireddy
> <rahul.lakkireddy@chelsio.com>
> Cc: dev@dpdk.org; Ori Kam <orika@nvidia.com>
> Subject: Re: [PATCH v3] ethdev: deprecate header fields and metadata flow
> actions
> 
> On 11/25/2021 2:13 PM, Slava Ovsiienko wrote:
> >> -----Original Message-----
> >> From: Thomas Monjalon <thomas@monjalon.net>
> >> Sent: Thursday, November 25, 2021 15:07
> >> To: Andrew Rybchenko <andrew.rybchenko@oktetlabs.ru>; Ajit Khaparde
> >> <ajit.khaparde@broadcom.com>; Somnath Kotur
> >> <somnath.kotur@broadcom.com>; Rahul Lakkireddy
> >> <rahul.lakkireddy@chelsio.com>; Slava Ovsiienko
> >> <viacheslavo@nvidia.com>; Ferruh Yigit <ferruh.yigit@intel.com>
> >> Cc: dev@dpdk.org; Ori Kam <orika@nvidia.com>
> >> Subject: Re: [PATCH v3] ethdev: deprecate header fields and metadata
> >> flow actions
> >>
> >> 25/11/2021 12:53, Ferruh Yigit:
> >>> On 11/24/2021 3:37 PM, Viacheslav Ovsiienko wrote:
> >>>> The generic RTE_FLOW_ACTION_TYPE_MODIFY_FIELD action was
> >> introduced
> >>>> by [1]. This action provides an unified way to perform various
> >>>> arithmetic and transfer operations over packet network header
> >>>> fields and packet metadata.
> >>>>
> >>>> [1] commit 641dbe4fb053 ("net/mlx5: support modify field flow
> >>>> action")
> >>>>

[..snip..]

> > +1
> > Dropping VLAN might trigger an avalanche of changes in applications - it is
> supported by multiple PMDs and should be widely engaged.
> > Other legacy actions are supported by very limited set of drivers and usage
> area should be smaller, I would say risk is moderate.
> >
> 
> Got it, 'SET_VLAN*' is treat differently because its impact can be more.
> 
> Can we do the same for other implemented actions, support them longer and
> give more time for deprecation.
> How big will be the maintenance cost in the PMD?

Yes, I share your concern. Sure, there should be the time period of handling both
actions. And there is our intention for mlx5 at least. I think development/maintenance 
costs should not raise significantly - the main efforts is supposed for implementing
MODIFY_FIELD action. 

Please, see my previous mail about milestones.

With best regards,
Slava