@@ -49,9 +49,52 @@ loaded.
The results will appear in TAP format in ``dmesg``.
+debugfs
+=======
+
+KUnit can be accessed from userspace via the debugfs filesystem (See more
+information about debugfs at Documentation/filesystems/debugfs.rst).
+
+If ``CONFIG_KUNIT_DEBUGFS`` is enabled, the KUnit debugfs filesystem is
+mounted at /sys/kernel/debug/kunit. You can use this filesystem to perform
+the following actions.
+
+Retrieve Test Results
+=====================
+
+You can use debugfs to retrieve KUnit test results. The test results are
+accessible from the debugfs filesystem in the following read-only file:
+
+.. code-block :: bash
+
+ /sys/kernel/debug/kunit/<test_suite>/results
+
+The test results are printed in a KTAP document. Note this document is separate
+to the kernel log and thus, may have different test suite numbering.
+
+Run Tests After Kernel Has Booted
+=================================
+
+You can use the debugfs filesystem to trigger built-in tests to run after
+boot. To run the test suite, you can use the following command to write to
+the ``/sys/kernel/debug/kunit/<test_suite>/run`` file:
+
+.. code-block :: bash
+
+ echo "any string" > /sys/kernel/debugfs/kunit/<test_suite>/run
+
+As a result, the test suite runs and the results are printed to the kernel
+log.
+
+However, this feature is not available with KUnit suites that use init data,
+because init data may have been discarded after the kernel boots. KUnit
+suites that use init data should be defined using the
+kunit_test_init_section_suites() macro.
+
+Also, you cannot use this feature to run tests concurrently. Instead a test
+will wait to run until other tests have completed or failed.
+
.. note ::
- If ``CONFIG_KUNIT_DEBUGFS`` is enabled, KUnit test results will
- be accessible from the ``debugfs`` filesystem (if mounted).
- They will be in ``/sys/kernel/debug/kunit/<test_suite>/results``, in
- TAP format.
+ For test authors, to use this feature, tests will need to correctly initialise
+ and/or clean up any data, so the test runs correctly a second time.
Expand the documentation on the KUnit debugfs filesystem on the run_manual.rst page. Add section describing how to access results using debugfs. Add section describing how to run tests after boot using debugfs. Signed-off-by: Rae Moar <rmoar@google.com> --- Changes since v3: - Change the introduction of the debugfs section - Add detail to not being able to run concurrently or run with init data Documentation/dev-tools/kunit/run_manual.rst | 51 ++++++++++++++++++-- 1 file changed, 47 insertions(+), 4 deletions(-)