diff --git a/block/blk-cgroup.c b/block/blk-cgroup.c
index 455768a..77ee3c1 100644
--- a/block/blk-cgroup.c
+++ b/block/blk-cgroup.c
@@ -371,12 +371,14 @@
 }
 EXPORT_SYMBOL_GPL(blkiocg_update_io_remove_stats);
 
-void blkiocg_update_timeslice_used(struct blkio_group *blkg, unsigned long time)
+void blkiocg_update_timeslice_used(struct blkio_group *blkg, unsigned long time,
+				unsigned long unaccounted_time)
 {
 	unsigned long flags;
 
 	spin_lock_irqsave(&blkg->stats_lock, flags);
 	blkg->stats.time += time;
+	blkg->stats.unaccounted_time += unaccounted_time;
 	spin_unlock_irqrestore(&blkg->stats_lock, flags);
 }
 EXPORT_SYMBOL_GPL(blkiocg_update_timeslice_used);
@@ -603,6 +605,9 @@
 	if (type == BLKIO_STAT_SECTORS)
 		return blkio_fill_stat(key_str, MAX_KEY_LEN - 1,
 					blkg->stats.sectors, cb, dev);
+	if (type == BLKIO_STAT_UNACCOUNTED_TIME)
+		return blkio_fill_stat(key_str, MAX_KEY_LEN - 1,
+					blkg->stats.unaccounted_time, cb, dev);
 #ifdef CONFIG_DEBUG_BLK_CGROUP
 	if (type == BLKIO_STAT_AVG_QUEUE_SIZE) {
 		uint64_t sum = blkg->stats.avg_queue_size_sum;
@@ -1106,6 +1111,9 @@
 		case BLKIO_PROP_sectors:
 			return blkio_read_blkg_stats(blkcg, cft, cb,
 						BLKIO_STAT_SECTORS, 0);
+		case BLKIO_PROP_unaccounted_time:
+			return blkio_read_blkg_stats(blkcg, cft, cb,
+						BLKIO_STAT_UNACCOUNTED_TIME, 0);
 		case BLKIO_PROP_io_service_bytes:
 			return blkio_read_blkg_stats(blkcg, cft, cb,
 						BLKIO_STAT_SERVICE_BYTES, 1);
@@ -1262,6 +1270,12 @@
 		.read_map = blkiocg_file_read_map,
 	},
 	{
+		.name = "unaccounted_time",
+		.private = BLKIOFILE_PRIVATE(BLKIO_POLICY_PROP,
+				BLKIO_PROP_unaccounted_time),
+		.read_map = blkiocg_file_read_map,
+	},
+	{
 		.name = "io_service_bytes",
 		.private = BLKIOFILE_PRIVATE(BLKIO_POLICY_PROP,
 				BLKIO_PROP_io_service_bytes),