diff --git a/kernel/time/tick-sched.c b/kernel/time/tick-sched.c
index 51556b9..b43bccb 100644
--- a/kernel/time/tick-sched.c
+++ b/kernel/time/tick-sched.c
@@ -422,13 +422,12 @@ static inline void tick_nohz_switch_to_nohz(void) { }
 #ifdef CONFIG_HIGH_RES_TIMERS
 /*
  * We rearm the timer until we get disabled by the idle code
- * Called with interrupts disabled and timer->base->cpu_base->lock held.
+ * Called with interrupts disabled and timer->base->cpu_base->lock *not* held.
  */
 static enum hrtimer_restart tick_sched_timer(struct hrtimer *timer)
 {
 	struct tick_sched *ts =
 		container_of(timer, struct tick_sched, sched_timer);
-	struct hrtimer_cpu_base *base = timer->base->cpu_base;
 	struct pt_regs *regs = get_irq_regs();
 	ktime_t now = ktime_get();
 
@@ -454,13 +453,12 @@ static enum hrtimer_restart tick_sched_timer(struct hrtimer *timer)
 		}
 		/*
 		 * update_process_times() might take tasklist_lock, hence
-		 * drop the base lock. sched-tick hrtimers are per-CPU and
-		 * never accessible by userspace APIs, so this is safe to do.
+		 * we don't attempt to grab the base lock here.
+		 * sched-tick hrtimers are per-CPU and never accessible by
+		 * userspace APIs, so this is safe to do.
 		 */
-		spin_unlock(&base->lock);
 		update_process_times(user_mode(regs));
 		profile_tick(CPU_PROFILING);
-		spin_lock(&base->lock);
 	}
 
 	/* Do not restart, when we are in the idle loop */