[dpdk-dev] [PATCH v11 1/6] ethdev: add Tx preparation

[Ananyev, Konstantin]

> -----Original Message-----
> From: Thomas Monjalon [mailto:thomas.monjalon at 6wind.com]
> Sent: Friday, October 28, 2016 11:22 AM
> To: Ananyev, Konstantin <konstantin.ananyev at intel.com>; Kulasek, TomaszX <tomaszx.kulasek at intel.com>
> Cc: dev at dpdk.org
> Subject: Re: [dpdk-dev] [PATCH v11 1/6] ethdev: add Tx preparation
> 
> 2016-10-28 10:15, Ananyev, Konstantin:
> > > From: Ananyev, Konstantin
> > > > From: Thomas Monjalon [mailto:thomas.monjalon at 6wind.com]
> > > > > 2016-10-27 15:52, Ananyev, Konstantin:
> > > > > > > 2016-10-26 14:56, Tomasz Kulasek:
> > > > > > > > --- a/config/common_base
> > > > > > > > +++ b/config/common_base
> > > > > > > > +CONFIG_RTE_ETHDEV_TX_PREP=y
> > > > > > >
> > > > > > > We cannot enable it until it is implemented in every drivers.
> > > > > >
> > > > > > Not sure why?
> > > > > > If tx_pkt_prep == NULL, then rte_eth_tx_prep() would just act as noop.
> > > > > > Right now it is not mandatory for the PMD to implement it.
> > > > >
> > > > > If it is not implemented, the application must do the preparation by
> > > > itself.
> > > > > From patch 6:
> > > > > "
> > > > > Removed pseudo header calculation for udp/tcp/tso packets from
> > > > > application and used Tx preparation API for packet preparation and
> > > > > verification.
> > > > > "
> > > > > So how does it behave with other drivers?
> > > >
> > > > Hmm so it seems that we broke testpmd csumonly mode for non-intel
> > > > drivers..
> > > > My bad, missed that part completely.
> > > > Yes, then I suppose for now we'll need to support both (with and without)
> > > > code paths for testpmd.
> > > > Probably a new fwd mode or just extra parameter for the existing one?
> > > > Any other suggestions?
> > > >
> > >
> > > I had sent txprep engine in v2 (http://dpdk.org/dev/patchwork/patch/15775/), but I'm opened on the suggestions. If you like it I can
> resent
> > > it in place of csumonly modification.
> >
> > I still not sure it is worth to have another version of csum...
> > Can we introduce a new global variable in testpmd and a new command:
> > testpmd> csum tx_prep
> > or so?
> > Looking at current testpmd patch, I suppose the changes will be minimal.
> > What do you think?
> 
> No please no!
> The problem is not in testpmd.
> The problem is in every applications.
> Should we prepare the checksums or let tx_prep do it?

Not sure, I understood you...
Right now we don't' change other apps.
They would work as before.
If people would like to start to use tx_prep in their apps -
they are free to do that.
If they like to keep doing that manually - that's fine too.
>From other side we need an ability to test (and demonstrate) that new functionality.
So we do need changes in testpmd.
Konstantin



> The result will depend of the driver used.