diff --git a/block/blk-iolatency.c b/block/blk-iolatency.c
index 2102744d39637554bb858fcc23c4fd2e2c05500a..2d89cd8560281658ef172cdf8a98e4f9ebecd75d 100644
--- a/block/blk-iolatency.c
+++ b/block/blk-iolatency.c
@@ -559,7 +559,7 @@ static void blkcg_iolatency_done_bio(struct rq_qos *rqos, struct bio *bio)
 	struct rq_wait *rqw;
 	struct iolatency_grp *iolat;
 	u64 window_start;
-	u64 now = ktime_to_ns(ktime_get());
+	u64 now;
 	bool issue_as_root = bio_issue_as_root_blkg(bio);
 	bool enabled = false;
 	int inflight = 0;
@@ -576,6 +576,7 @@ static void blkcg_iolatency_done_bio(struct rq_qos *rqos, struct bio *bio)
 	if (!enabled)
 		return;
 
+	now = ktime_to_ns(ktime_get());
 	while (blkg && blkg->parent) {
 		iolat = blkg_to_lat(blkg);
 		if (!iolat) {