What is kunit_tool?¶
kunit_tool is a script (
tools/testing/kunit/kunit.py) that aids in building
the Linux kernel as UML (User Mode Linux), running KUnit tests, parsing
the test results and displaying them in a user friendly manner.
kunit_tool addresses the problem of being able to run tests without needing a virtual machine or actual hardware with User Mode Linux. User Mode Linux is a Linux architecture, like ARM or x86; however, unlike other architectures it compiles the kernel as a standalone Linux executable that can be run like any other program directly inside of a host operating system. To be clear, it does not require any virtualization support: it is just a regular program.
What is a kunitconfig?¶
It’s just a defconfig that kunit_tool looks for in the base directory. kunit_tool uses it to generate a .config as you might expect. In addition, it verifies that the generated .config contains the CONFIG options in the kunitconfig; the reason it does this is so that it is easy to be sure that a CONFIG that enables a test actually ends up in the .config.
How do I use kunit_tool?¶
If a kunitconfig is present at the root directory, all you have to do is:
However, you most likely want to use it with the following options:
./tools/testing/kunit/kunit.py run --timeout=30 --jobs=`nproc --all`
--timeoutsets a maximum amount of time to allow tests to run.
--jobssets the number of threads to use to build the kernel.
If you just want to use the defconfig that ships with the kernel, you can
--defconfig flag as well:
./tools/testing/kunit/kunit.py run --timeout=30 --jobs=`nproc --all` --defconfig
This command is particularly helpful for getting started because it just works. No kunitconfig needs to be present.
For a list of all the flags supported by kunit_tool, you can run:
./tools/testing/kunit/kunit.py run --help