> +/* Set rq alloc and start time when pre-allocated rq is actually used */
> +static inline void blk_mq_rq_time_init(struct request_queue *q, struct request *rq)
> +{
> + if (blk_mq_need_time_stamp(rq->rq_flags)) {
> + u64 now = ktime_get_ns();
> +
> +#ifdef CONFIG_BLK_RQ_ALLOC_TIME
> + /*
> + * alloc time is only used by iocost for now,
> + * only possible when blk_mq_need_time_stamp().
> + */
> + if (blk_queue_rq_alloc_time(q))
> + rq->alloc_time_ns = now;
> +#endif
> + rq->start_time_ns = now;
> + }
> +}
No need to pass q separately here, you can just use rq->q.
While you're at it please capitalize the first letter of block comments.
