xref: /dpdk/doc/guides/sample_app_ug/packet_ordering.rst (revision 945acb4a0d644d194f1823084a234f9c286dcf8c)
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31Packet Ordering Application
32============================
33
34The Packet Ordering sample app simply shows the impact of reordering a stream.
35It's meant to stress the library with different configurations for performance.
36
37Overview
38--------
39
40The application uses at least three CPU cores:
41
42* RX core (maser core) receives traffic from the NIC ports and feeds Worker
43  cores with traffic through SW queues.
44
45* Worker core (slave core) basically do some light work on the packet.
46  Currently it modifies the output port of the packet for configurations with
47  more than one port enabled.
48
49* TX Core (slave core) receives traffic from Worker cores through software queues,
50  inserts out-of-order packets into reorder buffer, extracts ordered packets
51  from the reorder buffer and sends them to the NIC ports for transmission.
52
53Compiling the Application
54-------------------------
55
56To compile the sample application see :doc:`compiling`.
57
58The application is located in the ``packet_ordering`` sub-directory.
59
60Running the Application
61-----------------------
62
63Refer to *DPDK Getting Started Guide* for general information on running applications
64and the Environment Abstraction Layer (EAL) options.
65
66Application Command Line
67~~~~~~~~~~~~~~~~~~~~~~~~
68
69The application execution command line is:
70
71.. code-block:: console
72
73    ./test-pipeline [EAL options] -- -p PORTMASK [--disable-reorder]
74
75The -c EAL CPU_COREMASK option has to contain at least 3 CPU cores.
76The first CPU core in the core mask is the master core and would be assigned to
77RX core, the last to TX core and the rest to Worker cores.
78
79The PORTMASK parameter must contain either 1 or even enabled port numbers.
80When setting more than 1 port, traffic would be forwarded in pairs.
81For example, if we enable 4 ports, traffic from port 0 to 1 and from 1 to 0,
82then the other pair from 2 to 3 and from 3 to 2, having [0,1] and [2,3] pairs.
83
84The disable-reorder long option does, as its name implies, disable the reordering
85of traffic, which should help evaluate reordering performance impact.
86