4 /* Amount of time in which a process may batch requests */
5 #define BLK_BATCH_TIME (HZ/50UL)
7 /* Number of requests a "batching" process may submit */
8 #define BLK_BATCH_REQ 32
10 extern struct kmem_cache
*blk_requestq_cachep
;
11 extern struct kobj_type blk_queue_ktype
;
13 void init_request_from_bio(struct request
*req
, struct bio
*bio
);
14 void blk_rq_bio_prep(struct request_queue
*q
, struct request
*rq
,
16 void __blk_queue_free_tags(struct request_queue
*q
);
18 void blk_unplug_work(struct work_struct
*work
);
19 void blk_unplug_timeout(unsigned long data
);
21 struct io_context
*current_io_context(gfp_t gfp_flags
, int node
);
23 int ll_back_merge_fn(struct request_queue
*q
, struct request
*req
,
25 int ll_front_merge_fn(struct request_queue
*q
, struct request
*req
,
27 int attempt_back_merge(struct request_queue
*q
, struct request
*rq
);
28 int attempt_front_merge(struct request_queue
*q
, struct request
*rq
);
29 void blk_recalc_rq_segments(struct request
*rq
);
30 void blk_recalc_rq_sectors(struct request
*rq
, int nsect
);
32 void blk_queue_congestion_threshold(struct request_queue
*q
);
34 int blk_dev_init(void);
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.
41 static inline int queue_congestion_on_threshold(struct request_queue
*q
)
43 return q
->nr_congestion_on
;
47 * The threshold at which a queue is considered to be uncongested
49 static inline int queue_congestion_off_threshold(struct request_queue
*q
)
51 return q
->nr_congestion_off
;
54 #if defined(CONFIG_BLK_DEV_INTEGRITY)
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)
60 #endif /* BLK_DEV_INTEGRITY */