Function instance_set() expects to enable event 'sched_switch', so we should set 1 to its 'enable' file. Testcase passed after this patch: # ./ftracetest test.d/instances/instance-event.tc === Ftrace unit tests === [1] Test creation and deletion of trace instances while setting an event [PASS] # of passed: 1 # of failed: 0 # of unresolved: 0 # of untested: 0 # of unsupported: 0 # of xfailed: 0 # of undefined(test bug): 0 Signed-off-by: Zheng Yejian <zhengyejian1@xxxxxxxxxx> --- .../testing/selftests/ftrace/test.d/instances/instance-event.tc | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/tools/testing/selftests/ftrace/test.d/instances/instance-event.tc b/tools/testing/selftests/ftrace/test.d/instances/instance-event.tc index 0eb47fbb3f44..42422e425107 100644 --- a/tools/testing/selftests/ftrace/test.d/instances/instance-event.tc +++ b/tools/testing/selftests/ftrace/test.d/instances/instance-event.tc @@ -39,7 +39,7 @@ instance_read() { instance_set() { while :; do - echo 1 > foo/events/sched/sched_switch + echo 1 > foo/events/sched/sched_switch/enable done 2> /dev/null } -- 2.25.1