blob: ec898dd0c65c466ca2854ee987d7f178a83458d5 [file] [log] [blame]
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);
Jens Axboe8324aa92008-01-29 14:51:59 +010017void __blk_queue_free_tags(struct request_queue *q);
18
Jens Axboe86db1e22008-01-29 14:53:40 +010019void blk_unplug_work(struct work_struct *work);
20void blk_unplug_timeout(unsigned long data);
21
22struct io_context *current_io_context(gfp_t gfp_flags, int node);
23
Jens Axboed6d48192008-01-29 14:04:06 +010024int ll_back_merge_fn(struct request_queue *q, struct request *req,
25 struct bio *bio);
26int ll_front_merge_fn(struct request_queue *q, struct request *req,
27 struct bio *bio);
28int attempt_back_merge(struct request_queue *q, struct request *rq);
29int attempt_front_merge(struct request_queue *q, struct request *rq);
30void blk_recalc_rq_segments(struct request *rq);
31void blk_recalc_rq_sectors(struct request *rq, int nsect);
32
Jens Axboe8324aa92008-01-29 14:51:59 +010033void blk_queue_congestion_threshold(struct request_queue *q);
34
35/*
36 * Return the threshold (number of used requests) at which the queue is
37 * considered to be congested. It include a little hysteresis to keep the
38 * context switch rate down.
39 */
40static inline int queue_congestion_on_threshold(struct request_queue *q)
41{
42 return q->nr_congestion_on;
43}
44
45/*
46 * The threshold at which a queue is considered to be uncongested
47 */
48static inline int queue_congestion_off_threshold(struct request_queue *q)
49{
50 return q->nr_congestion_off;
51}
52
53#endif