diff --git a/engines/rbd.c b/engines/rbd.c
index cf7be0acd1e3..f3129044c430 100644
--- a/engines/rbd.c
+++ b/engines/rbd.c
@@ -20,6 +20,7 @@ struct rbd_data {
 	rados_ioctx_t io_ctx;
 	rbd_image_t image;
 	struct io_u **aio_events;
+	struct io_u **sort_events;
 };
 
 struct rbd_options {
@@ -80,20 +81,19 @@ static int _fio_setup_rbd_data(struct thread_data *td,
 	if (td->io_ops->data)
 		return 0;
 
-	rbd_data = malloc(sizeof(struct rbd_data));
+	rbd_data = calloc(1, sizeof(struct rbd_data));
 	if (!rbd_data)
 		goto failed;
 
-	memset(rbd_data, 0, sizeof(struct rbd_data));
-
-	rbd_data->aio_events = malloc(td->o.iodepth * sizeof(struct io_u *));
+	rbd_data->aio_events = calloc(td->o.iodepth, sizeof(struct io_u *));
 	if (!rbd_data->aio_events)
 		goto failed;
 
-	memset(rbd_data->aio_events, 0, td->o.iodepth * sizeof(struct io_u *));
+	rbd_data->sort_events = calloc(td->o.iodepth, sizeof(struct io_u *));
+	if (!rbd_data->sort_events)
+		goto failed;
 
 	*rbd_data_ptr = rbd_data;
-
 	return 0;
 
 failed:
@@ -218,14 +218,32 @@ static inline int fri_check_complete(struct rbd_data *rbd_data,
 	return 0;
 }
 
+static int rbd_io_u_cmp(const void *p1, const void *p2)
+{
+	const struct io_u **a = (const struct io_u **) p1;
+	const struct io_u **b = (const struct io_u **) p2;
+	uint64_t at, bt;
+
+	at = utime_since_now(&(*a)->start_time);
+	bt = utime_since_now(&(*b)->start_time);
+
+	if (at < bt)
+		return -1;
+	else if (at == bt)
+		return 0;
+	else
+		return 1;
+}
+
 static int rbd_iter_events(struct thread_data *td, unsigned int *events,
 			   unsigned int min_evts, int wait)
 {
 	struct rbd_data *rbd_data = td->io_ops->data;
 	unsigned int this_events = 0;
 	struct io_u *io_u;
-	int i;
+	int i, sort_idx;
 
+	sort_idx = 0;
 	io_u_qiter(&td->io_u_all, io_u, i) {
 		struct fio_rbd_iou *fri = io_u->engine_data;
 
@@ -236,16 +254,39 @@ static int rbd_iter_events(struct thread_data *td, unsigned int *events,
 
 		if (fri_check_complete(rbd_data, io_u, events))
 			this_events++;
-		else if (wait) {
-			rbd_aio_wait_for_complete(fri->completion);
+		else if (wait)
+			rbd_data->sort_events[sort_idx++] = io_u;
 
-			if (fri_check_complete(rbd_data, io_u, events))
-				this_events++;
-		}
 		if (*events >= min_evts)
 			break;
 	}
 
+	if (!wait || !sort_idx)
+		return this_events;
+
+	qsort(rbd_data->sort_events, sort_idx, sizeof(struct io_u *), rbd_io_u_cmp);
+	for (i = 0; i < sort_idx; i++) {
+		struct fio_rbd_iou *fri;
+
+		io_u = rbd_data->sort_events[i];
+		fri = io_u->engine_data;
+
+		if (fri_check_complete(rbd_data, io_u, events)) {
+			this_events++;
+			continue;
+		}
+		if (!wait)
+			continue;
+
+		rbd_aio_wait_for_complete(fri->completion);
+
+		if (fri_check_complete(rbd_data, io_u, events))
+			this_events++;
+
+		if (wait && *events >= min_evts)
+			wait = 0;
+	}
+
 	return this_events;
 }
 
@@ -359,6 +400,7 @@ static void fio_rbd_cleanup(struct thread_data *td)
 	if (rbd_data) {
 		_fio_rbd_disconnect(rbd_data);
 		free(rbd_data->aio_events);
+		free(rbd_data->sort_events);
 		free(rbd_data);
 	}