Merge "perf: Add support for exclude_idle attribute"

1 files changed, 27 insertions, 3 deletions

diff --git a/kernel/events/core.c b/kernel/events/core.c
index 96100cc046c5..32e2617d654f 100644
--- a/kernel/events/core.c
+++ b/kernel/events/core.c
@@ -158,6 +158,7 @@ enum event_type_t {
 struct static_key_deferred perf_sched_events __read_mostly;
 static DEFINE_PER_CPU(atomic_t, perf_cgroup_events);
 static DEFINE_PER_CPU(int, perf_sched_cb_usages);
+static DEFINE_PER_CPU(bool, is_idle);
 
 static atomic_t nr_mmap_events __read_mostly;
 static atomic_t nr_comm_events __read_mostly;
@@ -3388,9 +3389,12 @@ static int perf_event_read(struct perf_event *event, bool group)
 			.group = group,
 			.ret = 0,
 		};
-		smp_call_function_single(event->oncpu,
-					 __perf_event_read, &data, 1);
-		ret = data.ret;
+		if (!event->attr.exclude_idle ||
+					!per_cpu(is_idle, event->oncpu)) {
+			smp_call_function_single(event->oncpu,
+				__perf_event_read, &data, 1);
+			ret = data.ret;
+		}
 	} else if (event->state == PERF_EVENT_STATE_INACTIVE) {
 		struct perf_event_context *ctx = event->ctx;
 		unsigned long flags;
@@ -9479,6 +9483,25 @@ perf_cpu_notify(struct notifier_block *self, unsigned long action, void *hcpu)
 	return NOTIFY_OK;
 }
 
+static int event_idle_notif(struct notifier_block *nb, unsigned long action,
+							void *data)
+{
+	switch (action) {
+	case IDLE_START:
+		__this_cpu_write(is_idle, true);
+		break;
+	case IDLE_END:
+		__this_cpu_write(is_idle, false);
+		break;
+	}
+
+	return NOTIFY_OK;
+}
+
+static struct notifier_block perf_event_idle_nb = {
+	.notifier_call = event_idle_notif,
+};
+
 void __init perf_event_init(void)
 {
 	int ret;
@@ -9492,6 +9515,7 @@ void __init perf_event_init(void)
 	perf_pmu_register(&perf_task_clock, NULL, -1);
 	perf_tp_register();
 	perf_cpu_notifier(perf_cpu_notify);
+	idle_notifier_register(&perf_event_idle_nb);
 	register_reboot_notifier(&perf_reboot_notifier);
 
 	ret = init_hw_breakpoint();