On Mon, 2018-10-29 at 10:37 -0600, Jens Axboe wrote:
> -static inline struct blk_mq_hw_ctx *blk_mq_map_queue(struct request_queue *q,
> - unsigned int flags,
> - int cpu)
> +static inline struct blk_mq_hw_ctx *blk_mq_map_queue_type(struct
> request_queue *q,
> + int type, int cpu)
> {
> struct blk_mq_tag_set *set = q->tag_set;
>
> - return q->queue_hw_ctx[set->map[0].mq_map[cpu]];
> + return q->queue_hw_ctx[set->map[type].mq_map[cpu]];
> }
>
> -static inline struct blk_mq_hw_ctx *blk_mq_map_queue_type(struct
> request_queue *q,
> - int type, int cpu)
> +static inline struct blk_mq_hw_ctx *blk_mq_map_queue(struct request_queue *q,
> + unsigned int flags,
> + int cpu)
> {
> - return blk_mq_map_queue(q, type, cpu);
> + int type = 0;
> +
> + if (q->mq_ops->flags_to_type)
> + type = q->mq_ops->flags_to_type(q, flags);
> +
> + return blk_mq_map_queue_type(q, type, cpu);
> }
How about adding a comment above both these functions that explains their
purpose? Since blk_mq_map_queue() maps rq->cmd_flags and the cpu index to
a hardware context, how about renaming blk_mq_map_queue() into
blk_mq_map_cmd_flags()?
> /*
> diff --git a/include/linux/blk-mq.h b/include/linux/blk-mq.h
> index f9e19962a22f..837087cf07cc 100644
> --- a/include/linux/blk-mq.h
> +++ b/include/linux/blk-mq.h
> @@ -86,6 +86,7 @@ enum {
>
> struct blk_mq_tag_set {
> struct blk_mq_queue_map map[HCTX_MAX_TYPES];
> + unsigned int nr_maps;
> const struct blk_mq_ops *ops;
> unsigned int nr_hw_queues;
> unsigned int queue_depth; /* max hw supported */
> @@ -109,6 +110,7 @@ struct blk_mq_queue_data {
>
> typedef blk_status_t (queue_rq_fn)(struct blk_mq_hw_ctx *,
> const struct blk_mq_queue_data *);
> +typedef int (flags_to_type_fn)(struct request_queue *, unsigned int);
How about adding a comment that the format of the second argument of
flags_to_type_fn is the same as that of rq->cmd_flags?
Thanks,
Bart.
