1 files changed, 10 insertions, 2 deletions

diff --git a/kernel/hrtimer.c b/kernel/hrtimer.c
index 421be5fe5cc7..27a83ee41443 100644
--- a/kernel/hrtimer.c
+++ b/kernel/hrtimer.c
@@ -1003,10 +1003,18 @@ hrtimer_start(struct hrtimer *timer, ktime_t tim, const enum hrtimer_mode mode)
          */
         raise = timer->state == HRTIMER_STATE_PENDING;
 
+        /*
+         * We use preempt_disable to prevent this task from migrating after
+         * setting up the softirq and raising it. Otherwise, if me migrate
+         * we will raise the softirq on the wrong CPU.
+         */
+        preempt_disable();
+
         unlock_hrtimer_base(timer, &flags);
 
         if (raise)
                 hrtimer_raise_softirq();
+        preempt_enable();
 
         return ret;
 }
@@ -1078,7 +1086,7 @@ ktime_t hrtimer_get_remaining(const struct hrtimer *timer)
 }
 EXPORT_SYMBOL_GPL(hrtimer_get_remaining);
 
-#if defined(CONFIG_NO_IDLE_HZ) || defined(CONFIG_NO_HZ)
+#ifdef CONFIG_NO_HZ
 /**
  * hrtimer_get_next_event - get the time until next expiry event
  *
@@ -1669,7 +1677,7 @@ void __init hrtimers_init(void)
                           (void *)(long)smp_processor_id());
         register_cpu_notifier(&hrtimers_nb);
 #ifdef CONFIG_HIGH_RES_TIMERS
-        open_softirq(HRTIMER_SOFTIRQ, run_hrtimer_softirq, NULL);
+        open_softirq(HRTIMER_SOFTIRQ, run_hrtimer_softirq);
 #endif
 }