Re: [dpdk-dev] [PATCH v2] doc: announce ABI change for rte_eth_dev structure

[Jerin Jacob <jerin.jacob@caviumnetworks.com>]

On Wed, Jul 27, 2016 at 01:59:01AM -0700, Thomas Monjalon wrote:
> > > Signed-off-by: Tomasz Kulasek <tomaszx.kulasek@intel.com>
> > > ---
> > > +* In 16.11 ABI changes are plained: the ``rte_eth_dev`` structure will be
> > > +  extended with new function pointer ``tx_pkt_prep`` allowing verification
> > > +  and processing of packet burst to meet HW specific requirements before
> > > +  transmit. Also new fields will be added to the ``rte_eth_desc_lim`` structure:
> > > +  ``nb_seg_max`` and ``nb_mtu_seg_max`` provideing information about number of
> > > +  segments limit to be transmitted by device for TSO/non-TSO packets.
> > 
> > Acked-by: Konstantin Ananyev <konstantin.ananyev@intel.com>
> 
> I think I understand you want to split the TX processing:
> 	1/ modify/write in mbufs
> 	2/ write in HW
> and let application decide:
> 	- where the TX prep is done (which core)

In what basics applications knows when and where to call tx_pkt_prep in fast path.
if all the time it needs to call before tx_burst then the PMD won't have/don't need this
callback waste cycles in fast path.Is this the expected behavior ?
Anything think it as compile time to make other PMDs wont suffer because
of this change.


> 	- what to do if the TX prep fail
> So adding some processing in this first part becomes "not too expensive" or
> "manageable" from the application point of view.
> 
> If I well understand the intent,
> 
> Acked-by: Thomas Monjalon <thomas.monjalon@6wind.com>
> (except typos ;)