[PATCH v8 kunit-next 4/4] kunit: update documentation to describe debugfs representation

[Alan Maguire]

Documentation should describe debugfs layout and semantics.

Signed-off-by: Alan Maguire <alan.maguire@xxxxxxxxxx>
Reviewed-by: Brendan Higgins <brendanhiggins@xxxxxxxxxx>
Reviewed-by: Frank Rowand <frank.rowand@xxxxxxxx>
---
 Documentation/dev-tools/kunit/usage.rst | 14 ++++++++++++++
 1 file changed, 14 insertions(+)

diff --git a/Documentation/dev-tools/kunit/usage.rst b/Documentation/dev-tools/kunit/usage.rst
index 607758a..473a236 100644
--- a/Documentation/dev-tools/kunit/usage.rst
+++ b/Documentation/dev-tools/kunit/usage.rst
@@ -591,3 +591,17 @@ able to run one test case per invocation.
 
 .. TODO(brendanhiggins@xxxxxxxxxx): Add an actual example of an architecture
    dependent KUnit test.
+
+KUnit debugfs representation
+============================
+When kunit test suites are initialized, they create an associated directory
+in /sys/kernel/debug/kunit/<test-suite>.  The directory contains one file
+
+- results: "cat results" displays results of each test case and the results
+  of the entire suite for the last test run.
+
+The debugfs representation is primarily of use when kunit test suites are
+run in a native environment, either as modules or builtin.  Having a way
+to display results like this is valuable as otherwise results can be
+intermixed with other events in dmesg output.  The maximum size of each
+results file is KUNIT_LOG_SIZE bytes (defined in include/kunit/test.h).
-- 
1.8.3.1