]>
Commit | Line | Data |
---|---|---|
7c673cae FG |
1 | .. BSD LICENSE |
2 | Copyright(c) 2010-2014 Intel Corporation. All rights reserved. | |
3 | All rights reserved. | |
4 | ||
5 | Redistribution and use in source and binary forms, with or without | |
6 | modification, are permitted provided that the following conditions | |
7 | are met: | |
8 | ||
9 | * Redistributions of source code must retain the above copyright | |
10 | notice, this list of conditions and the following disclaimer. | |
11 | * Redistributions in binary form must reproduce the above copyright | |
12 | notice, this list of conditions and the following disclaimer in | |
13 | the documentation and/or other materials provided with the | |
14 | distribution. | |
15 | * Neither the name of Intel Corporation nor the names of its | |
16 | contributors may be used to endorse or promote products derived | |
17 | from this software without specific prior written permission. | |
18 | ||
19 | THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS | |
20 | "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT | |
21 | LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR | |
22 | A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT | |
23 | OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, | |
24 | SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT | |
25 | LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, | |
26 | DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY | |
27 | THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT | |
28 | (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE | |
29 | OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. | |
30 | ||
31 | Hello World Sample Application | |
32 | ============================== | |
33 | ||
34 | The Hello World sample application is an example of the simplest DPDK application that can be written. | |
35 | The application simply prints an "helloworld" message on every enabled lcore. | |
36 | ||
37 | Compiling the Application | |
38 | ------------------------- | |
39 | ||
40 | #. Go to the example directory: | |
41 | ||
42 | .. code-block:: console | |
43 | ||
44 | export RTE_SDK=/path/to/rte_sdk | |
45 | cd ${RTE_SDK}/examples/helloworld | |
46 | ||
47 | #. Set the target (a default target is used if not specified). For example: | |
48 | ||
49 | .. code-block:: console | |
50 | ||
51 | export RTE_TARGET=x86_64-native-linuxapp-gcc | |
52 | ||
53 | See the *DPDK Getting Started* Guide for possible RTE_TARGET values. | |
54 | ||
55 | #. Build the application: | |
56 | ||
57 | .. code-block:: console | |
58 | ||
59 | make | |
60 | ||
61 | Running the Application | |
62 | ----------------------- | |
63 | ||
64 | To run the example in a linuxapp environment: | |
65 | ||
66 | .. code-block:: console | |
67 | ||
68 | $ ./build/helloworld -c f -n 4 | |
69 | ||
70 | Refer to *DPDK Getting Started Guide* for general information on running applications | |
71 | and the Environment Abstraction Layer (EAL) options. | |
72 | ||
73 | Explanation | |
74 | ----------- | |
75 | ||
76 | The following sections provide some explanation of code. | |
77 | ||
78 | EAL Initialization | |
79 | ~~~~~~~~~~~~~~~~~~ | |
80 | ||
81 | The first task is to initialize the Environment Abstraction Layer (EAL). | |
82 | This is done in the main() function using the following code: | |
83 | ||
84 | .. code-block:: c | |
85 | ||
86 | int | |
87 | ||
88 | main(int argc, char **argv) | |
89 | ||
90 | { | |
91 | ret = rte_eal_init(argc, argv); | |
92 | if (ret < 0) | |
93 | rte_panic("Cannot init EAL\n"); | |
94 | ||
95 | This call finishes the initialization process that was started before main() is called (in case of a Linuxapp environment). | |
96 | The argc and argv arguments are provided to the rte_eal_init() function. | |
97 | The value returned is the number of parsed arguments. | |
98 | ||
99 | Starting Application Unit Lcores | |
100 | ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ | |
101 | ||
102 | Once the EAL is initialized, the application is ready to launch a function on an lcore. | |
103 | In this example, lcore_hello() is called on every available lcore. | |
104 | The following is the definition of the function: | |
105 | ||
106 | .. code-block:: c | |
107 | ||
108 | static int | |
109 | lcore_hello( attribute ((unused)) void *arg) | |
110 | { | |
111 | unsigned lcore_id; | |
112 | ||
113 | lcore_id = rte_lcore_id(); | |
114 | printf("hello from core %u\n", lcore_id); | |
115 | return 0; | |
116 | } | |
117 | ||
118 | The code that launches the function on each lcore is as follows: | |
119 | ||
120 | .. code-block:: c | |
121 | ||
122 | /* call lcore_hello() on every slave lcore */ | |
123 | ||
124 | RTE_LCORE_FOREACH_SLAVE(lcore_id) { | |
125 | rte_eal_remote_launch(lcore_hello, NULL, lcore_id); | |
126 | } | |
127 | ||
128 | /* call it on master lcore too */ | |
129 | ||
130 | lcore_hello(NULL); | |
131 | ||
132 | The following code is equivalent and simpler: | |
133 | ||
134 | .. code-block:: c | |
135 | ||
136 | rte_eal_mp_remote_launch(lcore_hello, NULL, CALL_MASTER); | |
137 | ||
138 | Refer to the *DPDK API Reference* for detailed information on the rte_eal_mp_remote_launch() function. |