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Documentation / kselftest.txt


Based on kernel version 4.10.8. Page generated on 2017-04-01 14:43 EST.

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 tests to exercise individual code
5	paths in the kernel. Tests are intended to be run after building, installing
6	and booting a kernel.
7	
8	On some systems, hot-plug tests could hang forever waiting for cpu and
9	memory to be ready to be offlined. A special hot-plug target is created
10	to run full range of hot-plug tests. In default mode, hot-plug tests run
11	in safe mode with a limited scope. In limited mode, cpu-hotplug test is
12	run on a single cpu as opposed to all hotplug capable cpus, and memory
13	hotplug test is run on 2% of hotplug capable memory instead of 10%.
14	
15	Running the selftests (hotplug tests are run in limited mode)
16	=============================================================
17	
18	To build the tests:
19	  $ make -C tools/testing/selftests
20	
21	
22	To run the tests:
23	  $ make -C tools/testing/selftests run_tests
24	
25	To 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	
31	Running a subset of selftests
32	========================================
33	You can use the "TARGETS" variable on the make command line to specify
34	single test to run, or a list of tests to run.
35	
36	To run only tests targeted for a single subsystem:
37	  $  make -C tools/testing/selftests TARGETS=ptrace run_tests
38	
39	You can specify multiple tests to build and run:
40	  $  make TARGETS="size timers" kselftest
41	
42	See the top-level tools/testing/selftests/Makefile for the list of all
43	possible targets.
44	
45	
46	Running the full range hotplug selftests
47	========================================
48	
49	To build the hotplug tests:
50	  $ make -C tools/testing/selftests hotplug
51	
52	To run the hotplug tests:
53	  $ make -C tools/testing/selftests run_hotplug
54	
55	- note that some tests will require root privileges.
56	
57	
58	Install selftests
59	=================
60	
61	You can use kselftest_install.sh tool installs selftests in default
62	location which is tools/testing/selftests/kselftest or an user specified
63	location.
64	
65	To install selftests in default location:
66	   $ cd tools/testing/selftests
67	   $ ./kselftest_install.sh
68	
69	To install selftests in an user specified location:
70	   $ cd tools/testing/selftests
71	   $ ./kselftest_install.sh install_dir
72	
73	Running installed selftests
74	===========================
75	
76	Kselftest install as well as the Kselftest tarball provide a script
77	named "run_kselftest.sh" to run the tests.
78	
79	You can simply do the following to run the installed Kselftests. Please
80	note some tests will require root privileges.
81	
82	cd kselftest
83	./run_kselftest.sh
84	
85	Contributing new tests
86	======================
87	
88	In 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.
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