Documentation/kselftest.txt

   1 Linux Kernel Selftests
   2
   3 The kernel contains a set of "self tests" under the tools/testing/selftests/
   4 directory. These are intended to be small unit tests to exercise individual
   5 code paths in the kernel.
   6
   7 On some systems, hot-plug tests could hang forever waiting for cpu and
   8 memory to be ready to be offlined. A special hot-plug target is created
   9 to run full range of hot-plug tests. In default mode, hot-plug tests run
  10 in safe mode with a limited scope. In limited mode, cpu-hotplug test is
  11 run on a single cpu as opposed to all hotplug capable cpus, and memory
  12 hotplug test is run on 2% of hotplug capable memory instead of 10%.
  13
  14 Running the selftests (hotplug tests are run in limited mode)
  15 =============================================================
  16
  17 To build the tests:
  18   $ make -C tools/testing/selftests
  19
  20
  21 To run the tests:
  22   $ make -C tools/testing/selftests run_tests
  23
  24 To 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
  30 Running a subset of selftests
  31 ========================================
  32 You can use the "TARGETS" variable on the make command line to specify
  33 single test to run, or a list of tests to run.
  34
  35 To run only tests targeted for a single subsystem:
  36   $  make -C tools/testing/selftests TARGETS=ptrace run_tests
  37
  38 You can specify multiple tests to build and run:
  39   $  make TARGETS="size timers" kselftest
  40
  41 See the top-level tools/testing/selftests/Makefile for the list of all
  42 possible targets.
  43
  44
  45 Running the full range hotplug selftests
  46 ========================================
  47
  48 To build the hotplug tests:
  49   $ make -C tools/testing/selftests hotplug
  50
  51 To run the hotplug tests:
  52   $ make -C tools/testing/selftests run_hotplug
  53
  54 - note that some tests will require root privileges.
  55
  56
  57 Contributing new tests
  58 ======================
  59
  60 In general, the rules for for selftests are
  61
  62  * Do as much as you can if you're not root;
  63
  64  * Don't take too long;
  65
  66  * Don't break the build on any architecture, and
  67
  68  * Don't cause the top-level "make run_tests" to fail if your feature is
  69    unconfigured.