tracing/ftrace: fix a bug when switch current tracer to sched tracer

Impact: fix boot tracer + sched tracer coupling bug

Fix a bug that made the sched_switch tracer unable to run
if set as the current_tracer after the boot tracer.

Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

1 files changed, 1 insertions, 1 deletions

diff --git a/kernel/trace/trace_sched_switch.c b/kernel/trace/trace_sched_switch.c
index 969953bf678f..888944d3409d 100644
--- a/kernel/trace/trace_sched_switch.c
+++ b/kernel/trace/trace_sched_switch.c
@@ -173,7 +173,7 @@ static void sched_switch_trace_init(struct trace_array *tr)
 
 static void sched_switch_trace_reset(struct trace_array *tr)
 {
-        if (tr->ctrl)
+        if (tr->ctrl && sched_ref)
                 stop_sched_trace(tr);
 }