Re: [PATCH 07/14] blk-mq: support multiple hctx maps
From: Bart Van Assche <bvanassche@acm.org>
Date: 2018-10-29 18:15:09
Also in:
linux-scsi, lkml
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()?
quoted hunk ↗ jump to hunk
/*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.