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Jens Axboe8324aa92008-01-29 14:51:59 +01001#ifndef BLK_INTERNAL_H
2#define BLK_INTERNAL_H
3
Jens Axboe86db1e22008-01-29 14:53:40 +01004/* Amount of time in which a process may batch requests */
5#define BLK_BATCH_TIME (HZ/50UL)
6
7/* Number of requests a "batching" process may submit */
8#define BLK_BATCH_REQ 32
9
Jens Axboe8324aa92008-01-29 14:51:59 +010010extern struct kmem_cache *blk_requestq_cachep;
11extern struct kobj_type blk_queue_ktype;
12
Jens Axboe86db1e22008-01-29 14:53:40 +010013void rq_init(struct request_queue *q, struct request *rq);
14void init_request_from_bio(struct request *req, struct bio *bio);
15void blk_rq_bio_prep(struct request_queue *q, struct request *rq,
16 struct bio *bio);
17int ll_back_merge_fn(struct request_queue *q, struct request *req,
18 struct bio *bio);
Jens Axboe8324aa92008-01-29 14:51:59 +010019void __blk_queue_free_tags(struct request_queue *q);
20
Jens Axboe86db1e22008-01-29 14:53:40 +010021void blk_unplug_work(struct work_struct *work);
22void blk_unplug_timeout(unsigned long data);
23
24struct io_context *current_io_context(gfp_t gfp_flags, int node);
25
Jens Axboe8324aa92008-01-29 14:51:59 +010026void blk_queue_congestion_threshold(struct request_queue *q);
27
28/*
29 * Return the threshold (number of used requests) at which the queue is
30 * considered to be congested. It include a little hysteresis to keep the
31 * context switch rate down.
32 */
33static inline int queue_congestion_on_threshold(struct request_queue *q)
34{
35 return q->nr_congestion_on;
36}
37
38/*
39 * The threshold at which a queue is considered to be uncongested
40 */
41static inline int queue_congestion_off_threshold(struct request_queue *q)
42{
43 return q->nr_congestion_off;
44}
45
46#endif