1 files changed, 13 insertions, 0 deletions

diff --git a/drivers/oprofile/timer_int.c b/drivers/oprofile/timer_int.c
index dc0ae4d14dff..010725117dbb 100644
--- a/drivers/oprofile/timer_int.c
+++ b/drivers/oprofile/timer_int.c
@@ -21,6 +21,7 @@
 #include "oprof.h"
 
 static DEFINE_PER_CPU(struct hrtimer, oprofile_hrtimer);
+static int ctr_running;
 
 static enum hrtimer_restart oprofile_hrtimer_notify(struct hrtimer *hrtimer)
 {
@@ -33,6 +34,9 @@ static void __oprofile_hrtimer_start(void *unused)
 {
         struct hrtimer *hrtimer = &__get_cpu_var(oprofile_hrtimer);
 
+        if (!ctr_running)
+                return;
+
         hrtimer_init(hrtimer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
         hrtimer->function = oprofile_hrtimer_notify;
 
@@ -42,7 +46,10 @@ static void __oprofile_hrtimer_start(void *unused)
 
 static int oprofile_hrtimer_start(void)
 {
+        get_online_cpus();
+        ctr_running = 1;
         on_each_cpu(__oprofile_hrtimer_start, NULL, 1);
+        put_online_cpus();
         return 0;
 }
 
@@ -50,6 +57,9 @@ static void __oprofile_hrtimer_stop(int cpu)
 {
         struct hrtimer *hrtimer = &per_cpu(oprofile_hrtimer, cpu);
 
+        if (!ctr_running)
+                return;
+
         hrtimer_cancel(hrtimer);
 }
 
@@ -57,8 +67,11 @@ static void oprofile_hrtimer_stop(void)
 {
         int cpu;
 
+        get_online_cpus();
         for_each_online_cpu(cpu)
                 __oprofile_hrtimer_stop(cpu);
+        ctr_running = 0;
+        put_online_cpus();
 }
 
 static int __cpuinit oprofile_cpu_notify(struct notifier_block *self,