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=========================================
Sample Application Tests: RX/TX Callbacks
=========================================

The RX/TX Callbacks sample application is a packet forwarding application that
demonstrates the use of user defined callbacks on received and transmitted
packets. The application performs a simple latency check, using callbacks, to
determine the time packets spend within the application.

In the sample application a user defined callback is applied to all received
packets to add a timestamp. A separate callback is applied to all packets
prior to transmission to calculate the elapsed time, in CPU cycles.

Running the Application
=======================

Open common_base and set ``CONFIG_RTE_ETHDEV_RXTX_CALLBACKS=y``.

To run the example in a ``linuxapp`` environment::

    ./build/rxtx_callbacks -c 2 -n 4

Refer to *DPDK Getting Started Guide* for general information on running
applications and the Environment Abstraction Layer (EAL) options.

test_rxtx_callbacks
===================

Running::

     ./examples/rxtx_callbacks/build/rxtx_callbacks -c 2 -n 4

waked up:::

     Core X forwarding packets.

Send one packet on Port0,check the port1 receive packet.
It receive one packet that the port0 send.