Re: [dpdk-dev] Is it possible to have dpdk running with no dependency on a nic ?

[Ymo Lists <ymolists@gmail.com>]

Than you so much Jayakumar for your help. Quick note. In the document you
pointed It states that

"Enqueuing and dequeuing items from an rte_ring using the rings-based PMD
may be slower than using the native rings API. This is because Intel® DPDK
Ethernet drivers make use of function pointers to call the appropriate
enqueue or dequeue functions, while the rte_ring specific functions are
direct function calls in the code and are often inlined by the compiler."

Is that statement correct ? I would imagine that inlined code would be be
faster than using function pointers ?

Also what are the native apis ? it does not make it very clear. could you
make it clear what is referrend as "native rings API" ?






On Fri, Feb 14, 2014 at 1:20 PM, Jayakumar, Muthurajan <
muthurajan.jayakumar@intel.com> wrote:

> Can you please refer Chapter 15.1.2 of the programmer's manual
> http://www.intel.com/content/dam/www/public/us/en/documents/guides/intel-dpdk-programmers-guide.pdftitled "Rings-based PMD".
> It indicates that  " To run an Intel(r) DPDK application on a machine
> without any Ethernet devices, a pair of ring-based rte_ethdevs can be used
> as below"
> As Vivek indicated, the ring based PMD (libte_pmd_ring) allows a set of
> s/w FIFOs (that is rte_ring) to be accessed using the PMD APIs, as though
> they were physical NICs"
>
> -----Original Message-----
> From: dev [mailto:dev-bounces@dpdk.org] On Behalf Of Ymo Lists
> Sent: Friday, February 14, 2014 9:20 AM
> Cc: dev@dpdk.org
> Subject: Re: [dpdk-dev] Is it possible to have dpdk running with no
> dependency on a nic ?
>
> Could you please point me to a sample doing this ? All the sample i have
> seen are initializing the eal and that involves initializing the nics. Is
> there a sample ? Can you mock up some code ?
>
> plz plzzz :-)
>
>
> On Fri, Feb 14, 2014 at 3:42 AM, Vivek Soni <tellviveks@gmail.com> wrote:
>
> > Yes, It is very well possible to run DPDK without dependency on the NIC.
> > But it all depends what you want to do.
> > The two DPDK applications can communicate using the ring library
> > provided by DPDK. In case there is no NIC, DPDK provides pure software
> > based PMDs which can be used on systems without a NIC or with
> > unsupported NIC using standard kernel drivers.
> >
> > Hope it helps.
> >
> > Regards,
> > Vivek
> >
> >
> > On Fri, Feb 14, 2014 at 1:49 AM, Ymo Lists <ymolists@gmail.com> wrote:
> >
> > > Is this a faq ???
> > >
> > >
> > > On Wed, Feb 12, 2014 at 1:21 PM, Ymo Lists <ymolists@gmail.com> wrote:
> > >
> > > > 1) I have two apps that need to communicate on the same machine .
> > > > Is it possible to have these two apps communicating via dpdk
> > > > without
> > > referencing
> > > > a nic ?
> > > >
> > > > 2) The apps need to run on an amazon vm. How can you run dpdk on
> > > > an
> > > amazon
> > > > vm with only one nic if the above is not possible ?
> > > >
> > >
> >
>