commit 79a9d461fd521f133f0e66485aa9ed09c21f5191
author Frederic Weisbecker <fweisbec@gmail.com> Fri Oct 31 13:34:45 2008 +0100
committer Ingo Molnar <mingo@elte.hu> Tue Nov 04 17:14:08 2008 +0100
tree ad90b0c05dabfa639855ee046c04bba77de85804
parent efade6e7821c4219818e9da08f9315dfa617048b

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>

kernel/trace/trace_sched_switch.c

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