1 .. SPDX-License-Identifier: GPL-2.0
2
3 ==========================
4 Frequently Asked Questions
5 ==========================
6
7 How is this different from Autotest, kselftest
8 ==============================================
9 KUnit is a unit testing framework. Autotest, k
10 not.
11
12 A `unit test <https://martinfowler.com/bliki/U
13 test a single unit of code in isolation and he
14 test should be the finest granularity of testi
15 code paths to be tested in the code under test
16 code under test is small and does not have any
17 the test's control like hardware.
18
19 There are no testing frameworks currently avai
20 require installing the kernel on a test machin
21 testing frameworks require tests to be written
22 kernel under test. This is true for Autotest,
23 disqualifying any of them from being considere
24
25 Does KUnit support running on architectures ot
26 ==============================================
27
28 Yes, mostly.
29
30 For the most part, the KUnit core framework (w
31 can compile to any architecture. It compiles l
32 kernel and runs when the kernel boots, or when
33 module is loaded. However, there is infrastru
34 (``tools/testing/kunit/kunit.py``) that might
35 (see :ref:`kunit-on-qemu`).
36
37 In short, yes, you can run KUnit on other arch
38 more work than using KUnit on UML.
39
40 For more information, see :ref:`kunit-on-non-u
41
42 .. _kinds-of-tests:
43
44 What is the difference between a unit test and
45 ==============================================
46 Most existing tests for the Linux kernel would
47 test, or an end-to-end test.
48
49 - A unit test is supposed to test a single uni
50 test should be the finest granularity of tes
51 possible code paths to be tested in the code
52 if the code under test is small and does not
53 outside of the test's control like hardware.
54 - An integration test tests the interaction be
55 usually just two or three. For example, some
56 test to test the interaction between a drive
57 test the interaction between the userspace l
58 the kernel itself. However, one of these tes
59 entire kernel along with hardware interactio
60 userspace.
61 - An end-to-end test usually tests the entire
62 code under test. For example, someone might
63 kernel by installing a production configurat
64 hardware with a production userspace and the
65 that depends on interactions between the har
66
67 KUnit is not working, what should I do?
68 =======================================
69
70 Unfortunately, there are a number of things wh
71 things to try.
72
73 1. Run ``./tools/testing/kunit/kunit.py run``
74 parameter. This might show details or error
75 parser.
76 2. Instead of running ``kunit.py run``, try ru
77 ``kunit.py build``, and ``kunit.py exec`` i
78 down where an issue is occurring. (If you t
79 can run it manually against ``stdin`` or a
80 3. Running the UML kernel directly can often r
81 ``kunit_tool`` ignores. This should be as s
82 after building the UML kernel (for example,
83 Note that UML has some unusual requirements
84 filesystem mounted), and has had issues in
85 the host has KASLR enabled. (On older host
86 ``setarch `uname -m` -R ./vmlinux`` to disa
87 4. Make sure the kernel .config has ``CONFIG_K
88 (e.g. ``CONFIG_KUNIT_EXAMPLE_TEST=y``). kun
89 around, so you can see what config was used
90 It also preserves any config changes you mi
91 enable/disable things with ``make ARCH=um m
92 re-run kunit_tool.
93 5. Try to run ``make ARCH=um defconfig`` befor
94 may help clean up any residual config items
95 6. Finally, try running KUnit outside UML. KUn
96 built into any kernel, or can be built as a
97 Doing so should allow you to determine if U
98 seeing. When tests are built-in, they will
99 modules will automatically execute associat
100 can be collected from ``/sys/kernel/debug/k
101 can be parsed with ``kunit.py parse``. For
102
103 If none of the above tricks help, you are alwa
104 kunit-dev@googlegroups.com.
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