---

yaml
---
r: 116346
b: refs/heads/master
c: fb02fbc
h: refs/heads/master
v: v3

[refs]

@@ -1,2 +1,2 @@
 ---
-refs/heads/master: c34bec5a44e9486597d78e7a686b2f9088a0564c
+refs/heads/master: fb02fbc14d17837b4b7b02dbb36142c16a7bf208

trunk/kernel/time/tick-broadcast.c

@@ -383,6 +383,19 @@ int tick_resume_broadcast_oneshot(struct clock_event_device *bc)
 	return 0;
 }
 
+/*
+ * Called from irq_enter() when idle was interrupted to reenable the
+ * per cpu device.
+ */
+void tick_check_oneshot_broadcast(int cpu)
+{
+	if (cpu_isset(cpu, tick_broadcast_oneshot_mask)) {
+		struct tick_device *td = &per_cpu(tick_cpu_device, cpu);
+
+		clockevents_set_mode(td->evtdev, CLOCK_EVT_MODE_ONESHOT);
+	}
+}
+
 /*
  * Handle oneshot mode broadcasting
  */

trunk/kernel/time/tick-internal.h

@@ -36,6 +36,7 @@ extern void tick_broadcast_switch_to_oneshot(void);
 extern void tick_shutdown_broadcast_oneshot(unsigned int *cpup);
 extern int tick_resume_broadcast_oneshot(struct clock_event_device *bc);
 extern int tick_broadcast_oneshot_active(void);
+extern void tick_check_oneshot_broadcast(int cpu);
 # else /* BROADCAST */
 static inline void tick_broadcast_setup_oneshot(struct clock_event_device *bc)
 {
@@ -45,6 +46,7 @@ static inline void tick_broadcast_oneshot_control(unsigned long reason) { }
 static inline void tick_broadcast_switch_to_oneshot(void) { }
 static inline void tick_shutdown_broadcast_oneshot(unsigned int *cpup) { }
 static inline int tick_broadcast_oneshot_active(void) { return 0; }
+static inline void tick_check_oneshot_broadcast(int cpu) { }
 # endif /* !BROADCAST */
 
 #else /* !ONESHOT */

trunk/kernel/time/tick-sched.c

@@ -508,10 +508,6 @@ static void tick_nohz_handler(struct clock_event_device *dev)
 	update_process_times(user_mode(regs));
 	profile_tick(CPU_PROFILING);
 
-	/* Do not restart, when we are in the idle loop */
-	if (ts->tick_stopped)
-		return;
-
 	while (tick_nohz_reprogram(ts, now)) {
 		now = ktime_get();
 		tick_do_update_jiffies64(now);
@@ -557,6 +553,27 @@ static void tick_nohz_switch_to_nohz(void)
 	       smp_processor_id());
 }
 
+/*
+ * When NOHZ is enabled and the tick is stopped, we need to kick the
+ * tick timer from irq_enter() so that the jiffies update is kept
+ * alive during long running softirqs. That's ugly as hell, but
+ * correctness is key even if we need to fix the offending softirq in
+ * the first place.
+ *
+ * Note, this is different to tick_nohz_restart. We just kick the
+ * timer and do not touch the other magic bits which need to be done
+ * when idle is left.
+ */
+static void tick_nohz_kick_tick(int cpu)
+{
+	struct tick_sched *ts = &per_cpu(tick_cpu_sched, cpu);
+
+	if (!ts->tick_stopped)
+		return;
+
+	tick_nohz_restart(ts, ktime_get());
+}
+
 #else
 
 static inline void tick_nohz_switch_to_nohz(void) { }
@@ -568,9 +585,11 @@ static inline void tick_nohz_switch_to_nohz(void) { }
  */
 void tick_check_idle(int cpu)
 {
+	tick_check_oneshot_broadcast(cpu);
 #ifdef CONFIG_NO_HZ
 	tick_nohz_stop_idle(cpu);
 	tick_nohz_update_jiffies();
+	tick_nohz_kick_tick(cpu);
 #endif
 }
 
@@ -627,10 +646,6 @@ static enum hrtimer_restart tick_sched_timer(struct hrtimer *timer)
 		profile_tick(CPU_PROFILING);
 	}
 
-	/* Do not restart, when we are in the idle loop */
-	if (ts->tick_stopped)
-		return HRTIMER_NORESTART;
-
 	hrtimer_forward(timer, now, tick_period);
 
 	return HRTIMER_RESTART;