Re: [dpdk-dev] [PATCH v3 1/5] ethdev: add API to negotiate delivery of Rx meta data

[Ori Kam <orika@nvidia.com>]

Hi

> -----Original Message-----
> From: Andrew Rybchenko <andrew.rybchenko@oktetlabs.ru>
> Sent: Wednesday, October 6, 2021 11:38 AM
> data
> 
> On 10/6/21 11:30 AM, Thomas Monjalon wrote:
> > 05/10/2021 13:11, Andrew Rybchenko:
> >> On 10/5/21 1:10 PM, Ori Kam wrote:
> >>> From: Andrew Rybchenko <andrew.rybchenko@oktetlabs.ru>
> >>>> On 10/5/21 12:41 PM, Ori Kam wrote:
> >>>>> From: Andrew Rybchenko <andrew.rybchenko@oktetlabs.ru>
> >>>>>> On 10/5/21 11:17 AM, Ori Kam wrote:
> >>>>>>> One more thing, I think this flag should be added now since you
> >>>>>>> need it, I think you should report that you don't support it.
> >>>>>>> since just like we talked there is no real difference between
> >>>>>>> metadata and
> >>>> MARK.
> >>>>>>> What do you think?
> >>>>>>
> >>>>>> It sounds like a trick :) Negative support is *not* a support in
> >>>>>> fact. DPDK policy requires support of a feature in a PMD and
> >>>>>> in-tree application. Of course, it is not a problem to add meta.
> >>>>>> It is really easy to do. I just don't want to add it in
> >>>>>> v5 to be deleted in v6 because of my above concerns.
> >>>>>>
> >>>>> This was not a trick. I understand what you are saying.
> >>>>> if we say that metadata is the same as mark, (I think we all agree
> >>>>> on
> >>>>> it) and that application need to notify pmd about such operations,
> >>>>> I assume it will try to see how to request the metadata.
> >>>>
> >>>> Frankly speaking I feel sick when I think about META and MARK
> >>>> together. Do we really need both in DPDK?
> >>>>
> >>> I realy don't want you the be sick,
> >>> The resoun that we need both of them is that 32 in Nvidia it is only
> >>> 24 bits of mark is not enough, so there is a need for more bits.
> >>> I think that in the end we will go to something much more generic
> >>> that the application will just say how many bits it wants to get and this
> what he will get.
> >>> for example the application may say it needs 128 bits and it will
> >>> register this size to the mbuf or give in the mbuf pointer two where those
> values should be set.
> >>> In any case as you can see we have already to many changes in
> >>> rte_flow in this release and the next one, but I'm planning to push
> >>> this feature in the future what do you think of such a feature?
> >>
> >> I agree that there are really many changes in flow API which are on
> >> review in the release cycle.
> >> I hope the above idea will allow to merge MARK and META.
> >
> > I agree we should merge mark and meta in a common dynamic mbuf field.
> > What do we need in mark which is not in meta?
> > I think dynamic mbuf field of meta is the way to go but I prefer the
> > name "mark" :)
> >
> 
> +1 but I don't have answer to the question

We have MARK, FLAG, and META.
MARK and FLAG are the same just one of them give predefined value.
we should merged those two for sure.
META allows the application to get more bits from the HW.
Like I said above I think we should merge everything.
but this is a talk for a different thread, and different time.

Ori