[dpdk-dev] Aligned RX data.

[Alex Markuze]

O.k, And how would I do that?
I'm guessing there is something I can control in rte_pktmbuf_pool_init?
I would appreciate If you could spare a word or two in the matter.

On Tue, Oct 7, 2014 at 7:11 PM, Ananyev, Konstantin <
konstantin.ananyev at intel.com> wrote:

>
>
> > -----Original Message-----
> > From: Ananyev, Konstantin
> > Sent: Tuesday, October 07, 2014 5:03 PM
> > To: Ananyev, Konstantin
> > Subject: FW: [dpdk-dev] Aligned RX data.
> >
> >
> >
> > From: Alex Markuze [mailto:alex at weka.io]
> > Sent: Tuesday, October 07, 2014 4:52 PM
> > To: Ananyev, Konstantin
> > Cc: dev at dpdk.org
> > Subject: Re: [dpdk-dev] Aligned RX data.
> >
> > RTE_PKTMBUF_HEADROOM defines the headroom
>
> Yes.
>
> >this would be true only if the buff_start was aligned to 512 which is not.
>
> As I said: " Make sure that your all your mbufs are aligned by 512".
>
> Konstantin
>
> >
> > On Tue, Oct 7, 2014 at 1:05 PM, Ananyev, Konstantin <
> konstantin.ananyev at intel.com> wrote:
> >
> >
> > > -----Original Message-----
> > > From: dev [mailto:dev-bounces at dpdk.org] On Behalf Of Alex Markuze
> > > Sent: Tuesday, October 07, 2014 10:40 AM
> > > To: dev at dpdk.org
> > > Subject: [dpdk-dev] Aligned RX data.
> > >
> > > Hi , I'm trying to receive aligned packets from the wire.
> > > Meaning that for all received packets the pkt.data is always aligned to
> > > (512 -H).
> > >
> > > Looking at the pmds of ixgbe/vmxnet I see that the pmds call
> > > __rte_mbuf_raw_alloc and set the rx descriptor with a
> > > RTE_MBUF_DATA_DMA_ADDR_DEFAULT
> > > Instead of the more appropriate RTE_MBUF_DATA_DMA_ADDR.
> > >
> > > Do I need to modify each pmd I'm using to be able to receive aligned
> data?
> > Make sure that your all your mbufs are aligned by 512 and set in your
> config RTE_PKTMBUF_HEADROOM=512-H?
> >
> >
> > > Or have I missed something?
> > >
> > > Thanks
>
>