diff --git a/kernel/events/core.c b/kernel/events/core.c
index 3f1f77d..b713080 100644
--- a/kernel/events/core.c
+++ b/kernel/events/core.c
@@ -1986,6 +1986,12 @@ static int perf_get_aux_event(struct perf_event *event,
 	return 1;
 }
 
+static inline struct list_head *get_event_list(struct perf_event *event)
+{
+	struct perf_event_context *ctx = event->ctx;
+	return event->attr.pinned ? &ctx->pinned_active : &ctx->flexible_active;
+}
+
 static void perf_group_detach(struct perf_event *event)
 {
 	struct perf_event *sibling, *tmp;
@@ -2028,12 +2034,8 @@ static void perf_group_detach(struct perf_event *event)
 		if (!RB_EMPTY_NODE(&event->group_node)) {
 			add_event_to_groups(sibling, event->ctx);
 
-			if (sibling->state == PERF_EVENT_STATE_ACTIVE) {
-				struct list_head *list = sibling->attr.pinned ?
-					&ctx->pinned_active : &ctx->flexible_active;
-
-				list_add_tail(&sibling->active_list, list);
-			}
+			if (sibling->state == PERF_EVENT_STATE_ACTIVE)
+				list_add_tail(&sibling->active_list, get_event_list(sibling));
 		}
 
 		WARN_ON_ONCE(sibling->ctx != event->ctx);
@@ -2350,6 +2352,8 @@ event_sched_in(struct perf_event *event,
 {
 	int ret = 0;
 
+	WARN_ON_ONCE(event->ctx != ctx);
+
 	lockdep_assert_held(&ctx->lock);
 
 	if (event->state <= PERF_EVENT_STATE_OFF)
@@ -3425,10 +3429,12 @@ struct sched_in_data {
 	int can_add_hw;
 };
 
-static int pinned_sched_in(struct perf_event *event, void *data)
+static int merge_sched_in(struct perf_event *event, void *data)
 {
 	struct sched_in_data *sid = data;
 
+	WARN_ON_ONCE(event->ctx != sid->ctx);
+
 	if (event->state <= PERF_EVENT_STATE_OFF)
 		return 0;
 
@@ -3437,37 +3443,15 @@ static int pinned_sched_in(struct perf_event *event, void *data)
 
 	if (group_can_go_on(event, sid->cpuctx, sid->can_add_hw)) {
 		if (!group_sched_in(event, sid->cpuctx, sid->ctx))
-			list_add_tail(&event->active_list, &sid->ctx->pinned_active);
+			list_add_tail(&event->active_list, get_event_list(event));
 	}
 
-	/*
-	 * If this pinned group hasn't been scheduled,
-	 * put it in error state.
-	 */
-	if (event->state == PERF_EVENT_STATE_INACTIVE)
-		perf_event_set_state(event, PERF_EVENT_STATE_ERROR);
+	if (event->state == PERF_EVENT_STATE_INACTIVE) {
+		if (event->attr.pinned)
+			perf_event_set_state(event, PERF_EVENT_STATE_ERROR);
 
-	return 0;
-}
-
-static int flexible_sched_in(struct perf_event *event, void *data)
-{
-	struct sched_in_data *sid = data;
-
-	if (event->state <= PERF_EVENT_STATE_OFF)
-		return 0;
-
-	if (!event_filter_match(event))
-		return 0;
-
-	if (group_can_go_on(event, sid->cpuctx, sid->can_add_hw)) {
-		int ret = group_sched_in(event, sid->cpuctx, sid->ctx);
-		if (ret) {
-			sid->can_add_hw = 0;
-			sid->ctx->rotate_necessary = 1;
-			return 0;
-		}
-		list_add_tail(&event->active_list, &sid->ctx->flexible_active);
+		sid->can_add_hw = 0;
+		sid->ctx->rotate_necessary = 1;
 	}
 
 	return 0;
@@ -3485,7 +3469,7 @@ ctx_pinned_sched_in(struct perf_event_context *ctx,
 
 	visit_groups_merge(&ctx->pinned_groups,
 			   smp_processor_id(),
-			   pinned_sched_in, &sid);
+			   merge_sched_in, &sid);
 }
 
 static void
@@ -3500,7 +3484,7 @@ ctx_flexible_sched_in(struct perf_event_context *ctx,
 
 	visit_groups_merge(&ctx->flexible_groups,
 			   smp_processor_id(),
-			   flexible_sched_in, &sid);
+			   merge_sched_in, &sid);
 }
 
 static void