selftest/ftrace: Fix function trigger test to handle trace not disabling the tracer

The ftrace selftest "ftrace - test for function traceon/off triggers"
enables all events and reads the trace file. Now that the trace file does
not disable tracing, and will attempt to continually read new data that is
added, the selftest gets stuck reading the trace file. This is because the
data added to the trace file will fill up quicker than the reading of it.

By only enabling scheduling events, the read can keep up with the writes.
Instead of enabling all events, only enable the scheduler events.

Link: http://lkml.kernel.org/r/20200318111345.0516642e@gandalf.local.home
Cc: Shuah Khan <skhan@linuxfoundation.org>
Cc: linux-kselftest@vger.kernel.org
Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>

diff --git a/tools/testing/selftests/ftrace/test.d/ftrace/func_traceonoff_triggers.tc b/tools/testing/selftests/ftrace/test.d/ftrace/func_traceonoff_triggers.tc
index 0c04282d33dd56813a25b08d341216bfa6a3ae5d..1947387fe97607f27f225546dffb7152f458198a 100644 (file)
--- a/tools/testing/selftests/ftrace/test.d/ftrace/func_traceonoff_triggers.tc
+++ b/tools/testing/selftests/ftrace/test.d/ftrace/func_traceonoff_triggers.tc
@@ -41,7 +41,7 @@ fi
 
 echo '** ENABLE EVENTS'
 
-echo 1 > events/enable
+echo 1 > events/sched/enable
 
 echo '** ENABLE TRACING'
 enable_tracing