Commit f98afe4f authored by Yu Kuai's avatar Yu Kuai Committed by Jens Axboe
Browse files

blk-mq: add a new queue sysfs attribute async_depth 



Add a new field async_depth to request_queue and related APIs, this is
currently not used, following patches will convert elevators to use
this instead of internal async_depth.

Signed-off-by: default avatarYu Kuai <yukuai@fnnas.com>
Reviewed-by: default avatarNilay Shroff <nilay@linux.ibm.com>
Signed-off-by: default avatarJens Axboe <axboe@kernel.dk>
parent cf02d7d4

block/blk-core.c

+1 −0
Original line number Diff line number Diff line
@@ -463,6 +463,7 @@ struct request_queue *blk_alloc_queue(struct queue_limits *lim, int node_id) 
	fs_reclaim_release(GFP_KERNEL);



	q->nr_requests = BLKDEV_DEFAULT_RQ;

	q->async_depth = BLKDEV_DEFAULT_RQ;



	return q;

block/blk-mq.c

+6 −0
Original line number Diff line number Diff line
@@ -4662,6 +4662,7 @@ int blk_mq_init_allocated_queue(struct blk_mq_tag_set *set, 
	spin_lock_init(&q->requeue_lock);



	q->nr_requests = set->queue_depth;

	q->async_depth = set->queue_depth;



	blk_mq_init_cpu_queues(q, set->nr_hw_queues);

	blk_mq_map_swqueue(q);
@@ -5028,6 +5029,11 @@ struct elevator_tags *blk_mq_update_nr_requests(struct request_queue *q, 
		q->elevator->et = et;

	}



	/*

	 * Preserve relative value, both nr and async_depth are at most 16 bit

	 * value, no need to worry about overflow.

	 */

	q->async_depth = max(q->async_depth * nr / q->nr_requests, 1);

	q->nr_requests = nr;

	if (q->elevator && q->elevator->type->ops.depth_updated)

		q->elevator->type->ops.depth_updated(q);

block/blk-sysfs.c

+42 −0
Original line number Diff line number Diff line
@@ -127,6 +127,46 @@ queue_requests_store(struct gendisk *disk, const char *page, size_t count) 
	return ret;

}



static ssize_t queue_async_depth_show(struct gendisk *disk, char *page)

{

	guard(mutex)(&disk->queue->elevator_lock);



	return queue_var_show(disk->queue->async_depth, page);

}



static ssize_t

queue_async_depth_store(struct gendisk *disk, const char *page, size_t count)

{

	struct request_queue *q = disk->queue;

	unsigned int memflags;

	unsigned long nr;

	int ret;



	if (!queue_is_mq(q))

		return -EINVAL;



	ret = queue_var_store(&nr, page, count);

	if (ret < 0)

		return ret;



	if (nr == 0)

		return -EINVAL;



	memflags = blk_mq_freeze_queue(q);

	scoped_guard(mutex, &q->elevator_lock) {

		if (q->elevator) {

			q->async_depth = min(q->nr_requests, nr);

			if (q->elevator->type->ops.depth_updated)

				q->elevator->type->ops.depth_updated(q);

		} else {

			ret = -EINVAL;

		}

	}

	blk_mq_unfreeze_queue(q, memflags);



	return ret;

}



static ssize_t queue_ra_show(struct gendisk *disk, char *page)

{

	ssize_t ret;
@@ -532,6 +572,7 @@ static struct queue_sysfs_entry _prefix##_entry = { \ 
}



QUEUE_RW_ENTRY(queue_requests, "nr_requests");

QUEUE_RW_ENTRY(queue_async_depth, "async_depth");

QUEUE_RW_ENTRY(queue_ra, "read_ahead_kb");

QUEUE_LIM_RW_ENTRY(queue_max_sectors, "max_sectors_kb");

QUEUE_LIM_RO_ENTRY(queue_max_hw_sectors, "max_hw_sectors_kb");
@@ -719,6 +760,7 @@ static struct attribute *blk_mq_queue_attrs[] = { 
	 */

	&elv_iosched_entry.attr,

	&queue_requests_entry.attr,

	&queue_async_depth_entry.attr,

#ifdef CONFIG_BLK_WBT

	&queue_wb_lat_entry.attr,

#endif

block/elevator.c

+1 −0
Original line number Diff line number Diff line
@@ -589,6 +589,7 @@ static int elevator_switch(struct request_queue *q, struct elv_change_ctx *ctx) 
		blk_queue_flag_clear(QUEUE_FLAG_SQ_SCHED, q);

		q->elevator = NULL;

		q->nr_requests = q->tag_set->queue_depth;

		q->async_depth = q->tag_set->queue_depth;

	}

	blk_add_trace_msg(q, "elv switch: %s", ctx->name);

include/linux/blkdev.h

+1 −0
Original line number Diff line number Diff line
@@ -551,6 +551,7 @@ struct request_queue { 
	 * queue settings

	 */

	unsigned int		nr_requests;	/* Max # of requests */

	unsigned int		async_depth;	/* Max # of async requests */



#ifdef CONFIG_BLK_INLINE_ENCRYPTION

	struct blk_crypto_profile *crypto_profile;