selftests/damon: skip test if DAMON is running

Testing the DAMON debugfs files while DAMON is running makes no sense,
as any write to the debugfs files will fail.  This commit makes the test
be skipped in this case.

Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: SeongJae Park <[email protected]>
Cc: Brendan Higgins <[email protected]>
Cc: Shuah Khan <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>

Author: sjp38

tools/testing/selftests/damon/debugfs_attrs.sh

@@ -44,6 +44,15 @@ test_content() {
 
 source ./_chk_dependency.sh
 
+ksft_skip=4
+
+damon_onoff="$DBGFS/monitor_on"
+if [ $(cat "$damon_onoff") = "on" ]
+then
+	echo "monitoring is on"
+	exit $ksft_skip
+fi
+
 # Test attrs file
 # ===============