LXR linux/Documentation/kselftest.txt

   1Linux Kernel Selftests
   2
   3The kernel contains a set of "self tests" under the tools/testing/selftests/
   4directory. These are intended to be small tests to exercise individual code
   5paths in the kernel. Tests are intended to be run after building, installing
   6and booting a kernel.
   7
   8On some systems, hot-plug tests could hang forever waiting for cpu and
   9memory to be ready to be offlined. A special hot-plug target is created
  10to run full range of hot-plug tests. In default mode, hot-plug tests run
  11in safe mode with a limited scope. In limited mode, cpu-hotplug test is
  12run on a single cpu as opposed to all hotplug capable cpus, and memory
  13hotplug test is run on 2% of hotplug capable memory instead of 10%.
  14
  15Running the selftests (hotplug tests are run in limited mode)
  16=============================================================
  17
  18To build the tests:
  19  $ make -C tools/testing/selftests
  20
  21
  22To run the tests:
  23  $ make -C tools/testing/selftests run_tests
  24
  25To build and run the tests with a single command, use:
  26  $ make kselftest
  27
  28- note that some tests will require root privileges.
  29
  30
  31Running a subset of selftests
  32========================================
  33You can use the "TARGETS" variable on the make command line to specify
  34single test to run, or a list of tests to run.
  35
  36To run only tests targeted for a single subsystem:
  37  $  make -C tools/testing/selftests TARGETS=ptrace run_tests
  38
  39You can specify multiple tests to build and run:
  40  $  make TARGETS="size timers" kselftest
  41
  42See the top-level tools/testing/selftests/Makefile for the list of all
  43possible targets.
  44
  45
  46Running the full range hotplug selftests
  47========================================
  48
  49To build the hotplug tests:
  50  $ make -C tools/testing/selftests hotplug
  51
  52To run the hotplug tests:
  53  $ make -C tools/testing/selftests run_hotplug
  54
  55- note that some tests will require root privileges.
  56
  57
  58Install selftests
  59=================
  60
  61You can use kselftest_install.sh tool installs selftests in default
  62location which is tools/testing/selftests/kselftest or an user specified
  63location.
  64
  65To install selftests in default location:
  66   $ cd tools/testing/selftests
  67   $ ./kselftest_install.sh
  68
  69To install selftests in an user specified location:
  70   $ cd tools/testing/selftests
  71   $ ./kselftest_install.sh install_dir
  72
  73Running installed selftests
  74===========================
  75
  76Kselftest install as well as the Kselftest tarball provide a script
  77named "run_kselftest.sh" to run the tests.
  78
  79You can simply do the following to run the installed Kselftests. Please
  80note some tests will require root privileges.
  81
  82cd kselftest
  83./run_kselftest.sh
  84
  85Contributing new tests
  86======================
  87
  88In general, the rules for selftests are
  89
  90 * Do as much as you can if you're not root;
  91
  92 * Don't take too long;
  93
  94 * Don't break the build on any architecture, and
  95
  96 * Don't cause the top-level "make run_tests" to fail if your feature is
  97   unconfigured.
  98