1.. SPDX-License-Identifier: BSD-3-Clause 2 Copyright(c) 2010-2014 Intel Corporation. 3 4Compiling and Running Sample Applications 5========================================= 6 7The chapter describes how to compile and run applications in an DPDK environment. 8It also provides a pointer to where sample applications are stored. 9 10.. note:: 11 12 Parts of this process can also be done using the setup script described the 13 :ref:`linux_setup_script` section of this document. 14 15Compiling a Sample Application 16------------------------------ 17 18Please refer to :ref:`building_app_using_installed_dpdk` for detail on compiling sample apps. 19 20Running a Sample Application 21---------------------------- 22 23.. warning:: 24 25 Before running the application make sure: 26 27 - Hugepages setup is done. 28 - Any kernel driver being used is loaded. 29 - In case needed, ports being used by the application should be 30 bound to the corresponding kernel driver. 31 32 refer to :ref:`linux_gsg_linux_drivers` for more details. 33 34The application is linked with the DPDK target environment's Environmental Abstraction Layer (EAL) library, 35which provides some options that are generic to every DPDK application. 36 37The following is the list of options that can be given to the EAL: 38 39.. code-block:: console 40 41 ./rte-app [-c COREMASK | -l CORELIST] [-n NUM] [-b <domain:bus:devid.func>] \ 42 [--socket-mem=MB,...] [-d LIB.so|DIR] [-m MB] [-r NUM] [-v] [--file-prefix] \ 43 [--proc-type <primary|secondary|auto>] 44 45The EAL options are as follows: 46 47* ``-c COREMASK`` or ``-l CORELIST``: 48 An hexadecimal bit mask of the cores to run on. Note that core numbering can 49 change between platforms and should be determined beforehand. The corelist is 50 a set of core numbers instead of a bitmap core mask. 51 52* ``-n NUM``: 53 Number of memory channels per processor socket. 54 55* ``-b <domain:bus:devid.func>``: 56 Blacklisting of ports; prevent EAL from using specified PCI device 57 (multiple ``-b`` options are allowed). 58 59* ``--use-device``: 60 use the specified Ethernet device(s) only. Use comma-separate 61 ``[domain:]bus:devid.func`` values. Cannot be used with ``-b`` option. 62 63* ``--socket-mem``: 64 Memory to allocate from hugepages on specific sockets. In dynamic memory mode, 65 this memory will also be pinned (i.e. not released back to the system until 66 application closes). 67 68* ``--socket-limit``: 69 Limit maximum memory available for allocation on each socket. Does not support 70 legacy memory mode. 71 72* ``-d``: 73 Add a driver or driver directory to be loaded. 74 The application should use this option to load the pmd drivers 75 that are built as shared libraries. 76 77* ``-m MB``: 78 Memory to allocate from hugepages, regardless of processor socket. It is 79 recommended that ``--socket-mem`` be used instead of this option. 80 81* ``-r NUM``: 82 Number of memory ranks. 83 84* ``-v``: 85 Display version information on startup. 86 87* ``--huge-dir``: 88 The directory where hugetlbfs is mounted. 89 90* ``mbuf-pool-ops-name``: 91 Pool ops name for mbuf to use. 92 93* ``--file-prefix``: 94 The prefix text used for hugepage filenames. 95 96* ``--proc-type``: 97 The type of process instance. 98 99* ``--vmware-tsc-map``: 100 Use VMware TSC map instead of native RDTSC. 101 102* ``--base-virtaddr``: 103 Specify base virtual address. 104 105* ``--vfio-intr``: 106 Specify interrupt type to be used by VFIO (has no effect if VFIO is not used). 107 108* ``--legacy-mem``: 109 Run DPDK in legacy memory mode (disable memory reserve/unreserve at runtime, 110 but provide more IOVA-contiguous memory). 111 112* ``--single-file-segments``: 113 Store memory segments in fewer files (dynamic memory mode only - does not 114 affect legacy memory mode). 115 116The ``-c`` or ``-l`` and option is mandatory; the others are optional. 117 118Copy the DPDK application binary to your target, then run the application as follows 119(assuming the platform has four memory channels per processor socket, 120and that cores 0-3 are present and are to be used for running the application):: 121 122 ./helloworld -l 0-3 -n 4 123 124.. note:: 125 126 The ``--proc-type`` and ``--file-prefix`` EAL options are used for running 127 multiple DPDK processes. See the "Multi-process Sample Application" 128 chapter in the *DPDK Sample Applications User Guide* and the *DPDK 129 Programmers Guide* for more details. 130 131Logical Core Use by Applications 132~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ 133 134The coremask (-c 0x0f) or corelist (-l 0-3) parameter is always mandatory for DPDK applications. 135Each bit of the mask corresponds to the equivalent logical core number as reported by Linux. The preferred corelist option is a cleaner method to define cores to be used. 136Since these logical core numbers, and their mapping to specific cores on specific NUMA sockets, can vary from platform to platform, 137it is recommended that the core layout for each platform be considered when choosing the coremask/corelist to use in each case. 138 139On initialization of the EAL layer by an DPDK application, the logical cores to be used and their socket location are displayed. 140This information can also be determined for all cores on the system by examining the ``/proc/cpuinfo`` file, for example, by running cat ``/proc/cpuinfo``. 141The physical id attribute listed for each processor indicates the CPU socket to which it belongs. 142This can be useful when using other processors to understand the mapping of the logical cores to the sockets. 143 144.. note:: 145 146 A more graphical view of the logical core layout may be obtained using the ``lstopo`` Linux utility. 147 On Fedora Linux, this may be installed and run using the following command:: 148 149 sudo yum install hwloc 150 ./lstopo 151 152.. warning:: 153 154 The logical core layout can change between different board layouts and should be checked before selecting an application coremask/corelist. 155 156Hugepage Memory Use by Applications 157~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ 158 159When running an application, it is recommended to use the same amount of memory as that allocated for hugepages. 160This is done automatically by the DPDK application at startup, 161if no ``-m`` or ``--socket-mem`` parameter is passed to it when run. 162 163If more memory is requested by explicitly passing a ``-m`` or ``--socket-mem`` value, the application fails. 164However, the application itself can also fail if the user requests less memory than the reserved amount of hugepage-memory, particularly if using the ``-m`` option. 165The reason is as follows. 166Suppose the system has 1024 reserved 2 MB pages in socket 0 and 1024 in socket 1. 167If the user requests 128 MB of memory, the 64 pages may not match the constraints: 168 169* The hugepage memory by be given to the application by the kernel in socket 1 only. 170 In this case, if the application attempts to create an object, such as a ring or memory pool in socket 0, it fails. 171 To avoid this issue, it is recommended that the ``--socket-mem`` option be used instead of the ``-m`` option. 172 173* These pages can be located anywhere in physical memory, and, although the DPDK EAL will attempt to allocate memory in contiguous blocks, 174 it is possible that the pages will not be contiguous. In this case, the application is not able to allocate big memory pools. 175 176The socket-mem option can be used to request specific amounts of memory for specific sockets. 177This is accomplished by supplying the ``--socket-mem`` flag followed by amounts of memory requested on each socket, 178for example, supply ``--socket-mem=0,512`` to try and reserve 512 MB for socket 1 only. 179Similarly, on a four socket system, to allocate 1 GB memory on each of sockets 0 and 2 only, the parameter ``--socket-mem=1024,0,1024`` can be used. 180No memory will be reserved on any CPU socket that is not explicitly referenced, for example, socket 3 in this case. 181If the DPDK cannot allocate enough memory on each socket, the EAL initialization fails. 182 183Additional Sample Applications 184------------------------------ 185 186Additional sample applications are included in the ${RTE_SDK}/examples directory. 187These sample applications may be built and run in a manner similar to that described in earlier sections in this manual. 188In addition, see the *DPDK Sample Applications User Guide* for a description of the application, 189specific instructions on compilation and execution and some explanation of the code. 190 191Additional Test Applications 192---------------------------- 193 194In addition, there are two other applications that are built when the libraries are created. 195The source files for these are in the DPDK/app directory and are called test and testpmd. 196Once the libraries are created, they can be found in the build/app directory. 197 198* The test application provides a variety of specific tests for the various functions in the DPDK. 199 200* The testpmd application provides a number of different packet throughput tests and 201 examples of features such as how to use the Flow Director found in the Intel® 82599 10 Gigabit Ethernet Controller. 202