---

yaml
---
r: 233551
b: refs/heads/master
c: 4fe757d
h: refs/heads/master
i:
  233549: 95ed869
  233547: 0e44b8b
  233543: 25c92c1
  233535: 678e63f
v: v3

[refs]

@@ -1,2 +1,2 @@
 ---
-refs/heads/master: 7d44ec193d95416d1342cdd86392a1eeb7461186
+refs/heads/master: 4fe757dd48a9e95e1a071291f15dda5421dacb66

trunk/kernel/perf_event.c

@@ -782,6 +782,10 @@ void perf_event_disable(struct perf_event *event)
 	raw_spin_unlock_irq(&ctx->lock);
 }
 
+#define MAX_INTERRUPTS (~0ULL)
+
+static void perf_log_throttle(struct perf_event *event, int enable);
+
 static int
 event_sched_in(struct perf_event *event,
 		 struct perf_cpu_context *cpuctx,
@@ -794,6 +798,17 @@ event_sched_in(struct perf_event *event,
 
 	event->state = PERF_EVENT_STATE_ACTIVE;
 	event->oncpu = smp_processor_id();
+
+	/*
+	 * Unthrottle events, since we scheduled we might have missed several
+	 * ticks already, also for a heavily scheduling task there is little
+	 * guarantee it'll get a tick in a timely manner.
+	 */
+	if (unlikely(event->hw.interrupts == MAX_INTERRUPTS)) {
+		perf_log_throttle(event, 1);
+		event->hw.interrupts = 0;
+	}
+
 	/*
 	 * The new state must be visible before we turn it on in the hardware:
 	 */
@@ -1596,10 +1611,6 @@ void __perf_event_task_sched_in(struct task_struct *task)
 	}
 }
 
-#define MAX_INTERRUPTS (~0ULL)
-
-static void perf_log_throttle(struct perf_event *event, int enable);
-
 static u64 perf_calculate_period(struct perf_event *event, u64 nsec, u64 count)
 {
 	u64 frequency = event->attr.sample_freq;