xref: /dpdk/doc/guides/sample_app_ug/packet_ordering.rst (revision e2a94f9ad3ef949c0df3e63699bd4e381b5003d9)
1..  SPDX-License-Identifier: BSD-3-Clause
2    Copyright(c) 2015 Intel Corporation.
3
4Packet Ordering Application
5============================
6
7The Packet Ordering sample app simply shows the impact of reordering a stream.
8It's meant to stress the library with different configurations for performance.
9
10Overview
11--------
12
13The application uses at least three CPU cores:
14
15* RX core (main core) receives traffic from the NIC ports and feeds Worker
16  cores with traffic through SW queues.
17
18* Worker (worker core) basically do some light work on the packet.
19  Currently it modifies the output port of the packet for configurations with
20  more than one port enabled.
21
22* TX Core (worker core) receives traffic from Worker cores through software queues,
23  inserts out-of-order packets into reorder buffer, extracts ordered packets
24  from the reorder buffer and sends them to the NIC ports for transmission.
25
26Compiling the Application
27-------------------------
28
29To compile the sample application see :doc:`compiling`.
30
31The application is located in the ``packet_ordering`` sub-directory.
32
33Running the Application
34-----------------------
35
36Refer to *DPDK Getting Started Guide* for general information on running applications
37and the Environment Abstraction Layer (EAL) options.
38
39Application Command Line
40~~~~~~~~~~~~~~~~~~~~~~~~
41
42The application execution command line is:
43
44.. code-block:: console
45
46    ./<build_dir>/examples/dpdk-packet_ordering [EAL options] -- -p PORTMASK /
47    [--disable-reorder] [--insight-worker]
48
49The -c EAL CPU_COREMASK option has to contain at least 3 CPU cores.
50The first CPU core in the core mask is the main core and would be assigned to
51RX core, the last to TX core and the rest to Worker cores.
52
53The PORTMASK parameter must contain either 1 or even enabled port numbers.
54When setting more than 1 port, traffic would be forwarded in pairs.
55For example, if we enable 4 ports, traffic from port 0 to 1 and from 1 to 0,
56then the other pair from 2 to 3 and from 3 to 2, having [0,1] and [2,3] pairs.
57
58The disable-reorder long option does, as its name implies, disable the reordering
59of traffic, which should help evaluate reordering performance impact.
60
61The insight-worker long option enables output the packet statistics of each worker thread.
62