trace-clock-get-may-fail

Trace clock get may fail

ARM pmu reservation may fail, so we have to change the trace clock get
prototype.

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>

2 files changed, 3 insertions, 2 deletions

diff --git a/arch/x86/include/asm/trace-clock.h b/arch/x86/include/asm/trace-clock.h
index ccdcb677aa5..01bc2f5221c 100644
--- a/arch/x86/include/asm/trace-clock.h
+++ b/arch/x86/include/asm/trace-clock.h
@@ -62,7 +62,7 @@ static inline u32 trace_clock_freq_scale(void)
 	return 1;
 }
 
-extern void get_trace_clock(void);
+extern int get_trace_clock(void);
 extern void put_trace_clock(void);
 
 extern void set_trace_clock_is_sync(int state);
diff --git a/arch/x86/kernel/trace-clock.c b/arch/x86/kernel/trace-clock.c
index b6c9d1fbb41..ec866aa9591 100644
--- a/arch/x86/kernel/trace-clock.c
+++ b/arch/x86/kernel/trace-clock.c
@@ -186,7 +186,7 @@ static int __cpuinit hotcpu_callback(struct notifier_block *nb,
 	return NOTIFY_OK;
 }
 
-void get_trace_clock(void)
+int get_trace_clock(void)
 {
 	int cpu;
 
@@ -212,6 +212,7 @@ void get_trace_clock(void)
 end:
 	spin_unlock(&async_tsc_lock);
 	put_online_cpus();
+	return 0;
 }
 EXPORT_SYMBOL_GPL(get_trace_clock);