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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 init_request_from_bio(struct request *req, struct bio *bio);
14void blk_rq_bio_prep(struct request_queue *q, struct request *rq,
15 struct bio *bio);
Jens Axboe8324aa92008-01-29 14:51:59 +010016void __blk_queue_free_tags(struct request_queue *q);
17
Jens Axboe86db1e22008-01-29 14:53:40 +010018void blk_unplug_work(struct work_struct *work);
19void blk_unplug_timeout(unsigned long data);
20
21struct io_context *current_io_context(gfp_t gfp_flags, int node);
22
Jens Axboed6d48192008-01-29 14:04:06 +010023int ll_back_merge_fn(struct request_queue *q, struct request *req,
24 struct bio *bio);
25int ll_front_merge_fn(struct request_queue *q, struct request *req,
26 struct bio *bio);
27int attempt_back_merge(struct request_queue *q, struct request *rq);
28int attempt_front_merge(struct request_queue *q, struct request *rq);
29void blk_recalc_rq_segments(struct request *rq);
30void blk_recalc_rq_sectors(struct request *rq, int nsect);
31
Jens Axboe8324aa92008-01-29 14:51:59 +010032void blk_queue_congestion_threshold(struct request_queue *q);
33
Adrian Bunkff889722008-03-04 11:23:45 +010034int blk_dev_init(void);
35
Jens Axboe8324aa92008-01-29 14:51:59 +010036/*
37 * Return the threshold (number of used requests) at which the queue is
38 * considered to be congested. It include a little hysteresis to keep the
39 * context switch rate down.
40 */
41static inline int queue_congestion_on_threshold(struct request_queue *q)
42{
43 return q->nr_congestion_on;
44}
45
46/*
47 * The threshold at which a queue is considered to be uncongested
48 */
49static inline int queue_congestion_off_threshold(struct request_queue *q)
50{
51 return q->nr_congestion_off;
52}
53
Martin K. Petersen7ba1ba12008-06-30 20:04:41 +020054#if defined(CONFIG_BLK_DEV_INTEGRITY)
55
56#define rq_for_each_integrity_segment(bvl, _rq, _iter) \
57 __rq_for_each_bio(_iter.bio, _rq) \
58 bip_for_each_vec(bvl, _iter.bio->bi_integrity, _iter.i)
59
60#endif /* BLK_DEV_INTEGRITY */
61
Jens Axboe8324aa92008-01-29 14:51:59 +010062#endif