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Documentation: Add debugfs docs with run after boot
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.
Reviewed-by: David Gow <davidgow@google.com>
Signed-off-by: Rae Moar <rmoar@google.com>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>
authored by
Rae Moar
and committed by
Shuah Khan
e9f0e21c
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Documentation/dev-tools/kunit/run_manual.rst
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Documentation/dev-tools/kunit/run_manual.rst
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The results will appear in TAP format in ``dmesg``.
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debugfs
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=======
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KUnit can be accessed from userspace via the debugfs filesystem (See more
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information about debugfs at Documentation/filesystems/debugfs.rst).
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If ``CONFIG_KUNIT_DEBUGFS`` is enabled, the KUnit debugfs filesystem is
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mounted at /sys/kernel/debug/kunit. You can use this filesystem to perform
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the following actions.
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Retrieve Test Results
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=====================
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You can use debugfs to retrieve KUnit test results. The test results are
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accessible from the debugfs filesystem in the following read-only file:
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.. code-block :: bash
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/sys/kernel/debug/kunit/<test_suite>/results
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The test results are printed in a KTAP document. Note this document is separate
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to the kernel log and thus, may have different test suite numbering.
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Run Tests After Kernel Has Booted
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=================================
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You can use the debugfs filesystem to trigger built-in tests to run after
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boot. To run the test suite, you can use the following command to write to
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the ``/sys/kernel/debug/kunit/<test_suite>/run`` file:
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.. code-block :: bash
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echo "any string" > /sys/kernel/debugfs/kunit/<test_suite>/run
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As a result, the test suite runs and the results are printed to the kernel
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log.
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However, this feature is not available with KUnit suites that use init data,
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because init data may have been discarded after the kernel boots. KUnit
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suites that use init data should be defined using the
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kunit_test_init_section_suites() macro.
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Also, you cannot use this feature to run tests concurrently. Instead a test
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will wait to run until other tests have completed or failed.
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.. note ::
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If ``CONFIG_KUNIT_DEBUGFS`` is enabled, KUnit test results will
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be accessible from the ``debugfs`` filesystem (if mounted).
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They will be in ``/sys/kernel/debug/kunit/<test_suite>/results``, in
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TAP format.
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For test authors, to use this feature, tests will need to correctly initialise
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and/or clean up any data, so the test runs correctly a second time.