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authorIngo Molnar <mingo@elte.hu>2011-02-16 13:27:18 +0100
committerIngo Molnar <mingo@elte.hu>2011-02-16 13:27:23 +0100
commitb00560f2d4de69bb12f66f9605985b516df98d77 (patch)
tree0c92fc994125dc3ddb635842715be29d8b16808b /kernel/perf_event.c
parentbf1af3a809506645b9130755b713b008da14737f (diff)
parent4fe757dd48a9e95e1a071291f15dda5421dacb66 (diff)
Merge branch 'perf/urgent' into perf/core
Merge reason: we need to queue up dependent patch Signed-off-by: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to 'kernel/perf_event.c')
-rw-r--r--kernel/perf_event.c19
1 files changed, 15 insertions, 4 deletions
diff --git a/kernel/perf_event.c b/kernel/perf_event.c
index a353a4d6d00d..3d3f282fa50e 100644
--- a/kernel/perf_event.c
+++ b/kernel/perf_event.c
@@ -851,6 +851,10 @@ retry:
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,
@@ -863,6 +867,17 @@ 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:
*/
@@ -1661,10 +1676,6 @@ 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;