3. Compiling the DPDK Target from Source

Note

Parts of this process can also be done using the setup script described in the Quick Start Setup Script section of this document.

3.1. Uncompress DPDK and Browse Sources

First, uncompress the archive and move to the uncompressed DPDK source directory:

tar xJf dpdk-<version>.tar.xz
cd dpdk-<version>

The DPDK is composed of several directories:

  • lib: Source code of DPDK libraries
  • drivers: Source code of DPDK poll-mode drivers
  • app: Source code of DPDK applications (automatic tests)
  • examples: Source code of DPDK application examples
  • config, buildtools, mk: Framework-related makefiles, scripts and configuration

3.2. Compiling and Installing DPDK System-wide

DPDK can be configured, built and installed on your system using the tools meson and ninja.

Note

The older makefile-based build system used in older DPDK releases is still present and its use is described in section Installation of DPDK Target Environment using Make.

3.2.1. DPDK Configuration

To configure a DPDK build use:

meson <options> build

where “build” is the desired output build directory, and “<options>” can be empty or one of a number of meson or DPDK-specific build options, described later in this section. The configuration process will finish with a summary of what DPDK libraries and drivers are to be built and installed, and for each item disabled, a reason why that is the case. This information can be used, for example, to identify any missing required packages for a driver.

Once configured, to build and then install DPDK system-wide use:

cd build
ninja
ninja install
ldconfig

The last two commands above generally need to be run as root, with the ninja install step copying the built objects to their final system-wide locations, and the last step causing the dynamic loader ld.so to update its cache to take account of the new objects.

Note

On some linux distributions, such as Fedora or Redhat, paths in /usr/local are not in the default paths for the loader. Therefore, on these distributions, /usr/local/lib and /usr/local/lib64 should be added to a file in /etc/ld.so.conf.d/ before running ldconfig.

3.2.2. Adjusting Build Options

DPDK has a number of options that can be adjusted as part of the build configuration process. These options can be listed by running meson configure inside a configured build folder. Many of these options come from the “meson” tool itself and can be seen documented on the Meson Website.

For example, to change the build-type from the default, “debugoptimized”, to a regular “debug” build, you can either:

  • pass -Dbuildtype=debug or --buildtype=debug to meson when configuring the build folder initially
  • run meson configure -Dbuildtype=debug inside the build folder after the initial meson run.

Other options are specific to the DPDK project but can be adjusted similarly. To set the “max_lcores” value to 256, for example, you can either:

  • pass -Dmax_lcores=256 to meson when configuring the build folder initially
  • run meson configure -Dmax_lcores=256 inside the build folder after the initial meson run.

Some of the DPDK sample applications in the examples directory can be automatically built as part of a meson build too. To do so, pass a comma-separated list of the examples to build to the -Dexamples meson option as below:

meson -Dexamples=l2fwd,l3fwd build

As with other meson options, this can also be set post-initial-config using meson configure in the build directory. There is also a special value “all” to request that all example applications whose dependencies are met on the current system are built. When -Dexamples=all is set as a meson option, meson will check each example application to see if it can be built, and add all which can be built to the list of tasks in the ninja build configuration file.

3.2.3. Building Applications Using Installed DPDK

When installed system-wide, DPDK provides a pkg-config file libdpdk.pc for applications to query as part of their build. It’s recommended that the pkg-config file be used, rather than hard-coding the parameters (cflags/ldflags) for DPDK into the application build process.

An example of how to query and use the pkg-config file can be found in the Makefile of each of the example applications included with DPDK. A simplified example snippet is shown below, where the target binary name has been stored in the variable $(APP) and the sources for that build are stored in $(SRCS-y).

PKGCONF = pkg-config

CFLAGS += -O3 $(shell $(PKGCONF) --cflags libdpdk)
LDFLAGS += $(shell $(PKGCONF) --libs libdpdk)

$(APP): $(SRCS-y) Makefile
        $(CC) $(CFLAGS) $(SRCS-y) -o $@ $(LDFLAGS)

Note

Unlike with the older make build system, the meson system is not designed to be used directly from a build directory. Instead it is recommended that it be installed either system-wide or to a known location in the user’s home directory. The install location can be set using the –prefix meson option (default: /usr/local).

an equivalent build recipe for a simple DPDK application using meson as a build system is shown below:

project('dpdk-app', 'c')

dpdk = dependency('libdpdk')
sources = files('main.c')
executable('dpdk-app', sources, dependencies: dpdk)

3.3. Installation of DPDK Target Environment using Make

Note

The building of DPDK using make will be deprecated in a future release. It is therefore recommended that DPDK installation is done using meson and ninja as described above.

The format of a DPDK target is:

ARCH-MACHINE-EXECENV-TOOLCHAIN

where:

  • ARCH can be: i686, x86_64, ppc_64, arm64
  • MACHINE can be: native, power8, armv8a
  • EXECENV can be: linux, freebsd
  • TOOLCHAIN can be: gcc, icc

The targets to be installed depend on the 32-bit and/or 64-bit packages and compilers installed on the host. Available targets can be found in the DPDK/config directory. The defconfig_ prefix should not be used.

Note

Configuration files are provided with the RTE_MACHINE optimization level set. Within the configuration files, the RTE_MACHINE configuration value is set to native, which means that the compiled software is tuned for the platform on which it is built. For more information on this setting, and its possible values, see the DPDK Programmers Guide.

When using the Intel® C++ Compiler (icc), one of the following commands should be invoked for 64-bit or 32-bit use respectively. Notice that the shell scripts update the $PATH variable and therefore should not be performed in the same session. Also, verify the compiler’s installation directory since the path may be different:

source /opt/intel/bin/iccvars.sh intel64
source /opt/intel/bin/iccvars.sh ia32

To install and make targets, use the make install T=<target> command in the top-level DPDK directory.

For example, to compile a 64-bit target using icc, run:

make install T=x86_64-native-linux-icc

To compile a 32-bit build using gcc, the make command should be:

make install T=i686-native-linux-gcc

To prepare a target without building it, for example, if the configuration changes need to be made before compilation, use the make config T=<target> command:

make config T=x86_64-native-linux-gcc

Warning

Any kernel modules to be used, e.g. igb_uio, kni, must be compiled with the same kernel as the one running on the target. If the DPDK is not being built on the target machine, the RTE_KERNELDIR environment variable should be used to point the compilation at a copy of the kernel version to be used on the target machine.

Once the target environment is created, the user may move to the target environment directory and continue to make code changes and re-compile. The user may also make modifications to the compile-time DPDK configuration by editing the .config file in the build directory. (This is a build-local copy of the defconfig file from the top- level config directory).

cd x86_64-native-linux-gcc
vi .config
make

In addition, the make clean command can be used to remove any existing compiled files for a subsequent full, clean rebuild of the code.

3.4. Browsing the Installed DPDK Environment Target

Once a target is created it contains all libraries, including poll-mode drivers, and header files for the DPDK environment that are required to build customer applications. In addition, the test and testpmd applications are built under the build/app directory, which may be used for testing. A kmod directory is also present that contains kernel modules which may be loaded if needed.