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