CODEWITHSUNDEEP
dpdk
user3078434
user3078434

Reputation: 51

How to send and receive data using DPDK

I have a quad port Intel 1G network card. I am using DPDK to send data on one physical port and receive on another.

I saw a few examples in DPDK code, but could not make it work. If anybody knows how to do that please send me simple instructions so I can follow and understand. I setup my PC properly for huge pages, loading driver, and assigning network port to use dpdk driver etc... I can run helloworld from DPDK so system setup looks ok to me.

Thanks in advance. temp5556

Upvotes: 5

Views: 9880

Answers (2)

Andrew Bainbridge
Andrew Bainbridge

Reputation: 4808

After building DPDK:

  1. cd to the DPDK directory.

  2. Run sudo build/app/testpmd -- --interactive

You should see output like this:

$ sudo build/app/testpmd -- --interactive
EAL: Detected 8 lcore(s)
EAL: No free hugepages reported in hugepages-1048576kB
EAL: Multi-process socket /var/run/.rte_unix
EAL: Probing VFIO support...
EAL: WARNING: cpu flags constant_tsc=yes nonstop_tsc=no -> using unreliable clock cycles !
EAL: PCI device 0002:00:02.0 on NUMA socket 0
EAL:   probe driver: 15b3:1004 net_mlx4
PMD: net_mlx4: PCI information matches, using device "mlx4_0" (VF: true)
PMD: net_mlx4: 1 port(s) detected
PMD: net_mlx4: port 1 MAC address is 00:0d:3a:f4:6e:17
Interactive-mode selected
testpmd: create a new mbuf pool <mbuf_pool_socket_0>: n=203456, size=2176, socket=0
testpmd: preferred mempool ops selected: ring_mp_mc

Warning! port-topology=paired and odd forward ports number, the last port
will pair with itself.

Configuring Port 0 (socket 0)
Port 0: 00:0D:3A:F4:6E:17
Checking link statuses...
Done
testpmd>

Don't worry about the "No free hugepages" message. It means it couldn't find any 1024 MB hugepages but it since it continued OK, it must have found some 2 MB hugepages. It'd be nice if it said "EAL: Using 2 MB huge pages" instead.

At the prompt type, start tx_first, then quit. You should see something like:

testpmd> start tx_first
io packet forwarding - ports=1 - cores=1 - streams=1 - NUMA support enabled, MP over anonymous pages disabled
Logical Core 1 (socket 0) forwards packets on 1 streams:
  RX P=0/Q=0 (socket 0) -> TX P=0/Q=0 (socket 0) peer=02:00:00:00:00:00

  io packet forwarding packets/burst=32
  nb forwarding cores=1 - nb forwarding ports=1
  port 0:
  CRC stripping enabled
  RX queues=1 - RX desc=1024 - RX free threshold=0
  RX threshold registers: pthresh=0 hthresh=0  wthresh=0
  TX queues=1 - TX desc=1024 - TX free threshold=0
  TX threshold registers: pthresh=0 hthresh=0  wthresh=0
  TX RS bit threshold=0 - TXQ offloads=0x0
testpmd> quit
Telling cores to stop...
Waiting for lcores to finish...

  ---------------------- Forward statistics for port 0  ----------------------
  RX-packets: 0              RX-dropped: 0             RX-total: 0
  TX-packets: 32             TX-dropped: 0             TX-total: 32
  ----------------------------------------------------------------------------

  +++++++++++++++ Accumulated forward statistics for all ports+++++++++++++++
  RX-packets: 0              RX-dropped: 0             RX-total: 0
  TX-packets: 32             TX-dropped: 0             TX-total: 32
  ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++

In my system there is only one DPDK port, so I sent 32 packets but did not receive any. If I had a multi-port card with a cable directly between the ports, then I'd see the RX count also increase.

Upvotes: 4

KhalidX9
KhalidX9

Reputation: 41

you can use TESTPMD to test DPDK.

TestPMD can work as a packet generator (tx_only mode) , a receiver (rx_only mode) , or a forwarder(io mode).

you will need generator nodes to be connected to your box if you are willing to use TESTPMD as a forwarder only.

I propose that you start with the following examples :

generator(pktgen) ------> testPMD (io mode )----------> recevier (testPMD rx_only mode).

at the pktgen generator specify the mac address destination which is the MAC address of the receive's receiving PORT.

PKTGEN and how it works in detail is explained more in this link :

http://pktgen.readthedocs.io/en/latest/getting_started.html

TESTPMD and how it works is explained here :

http://www.intel.com/content/dam/www/public/us/en/documents/guides/dpdk-testpmd-application-user-guide.pdf

I hope this helps.

Upvotes: 3

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