blob: ec9120fb789a67c560df9c12e38dc8e0cc46a008 [file] [log] [blame]
/* Amount of time in which a process may batch requests */
#define BLK_BATCH_TIME (HZ/50UL)
/* Number of requests a "batching" process may submit */
#define BLK_BATCH_REQ 32
extern struct kmem_cache *blk_requestq_cachep;
extern struct kobj_type blk_queue_ktype;
void rq_init(struct request_queue *q, struct request *rq);
void init_request_from_bio(struct request *req, struct bio *bio);
void blk_rq_bio_prep(struct request_queue *q, struct request *rq,
struct bio *bio);
void __blk_queue_free_tags(struct request_queue *q);
void blk_unplug_work(struct work_struct *work);
void blk_unplug_timeout(unsigned long data);
struct io_context *current_io_context(gfp_t gfp_flags, int node);
int ll_back_merge_fn(struct request_queue *q, struct request *req,
struct bio *bio);
int ll_front_merge_fn(struct request_queue *q, struct request *req,
struct bio *bio);
int attempt_back_merge(struct request_queue *q, struct request *rq);
int attempt_front_merge(struct request_queue *q, struct request *rq);
void blk_recalc_rq_segments(struct request *rq);
void blk_recalc_rq_sectors(struct request *rq, int nsect);
void blk_queue_congestion_threshold(struct request_queue *q);
int blk_dev_init(void);
* Return the threshold (number of used requests) at which the queue is
* considered to be congested. It include a little hysteresis to keep the
* context switch rate down.
static inline int queue_congestion_on_threshold(struct request_queue *q)
return q->nr_congestion_on;
* The threshold at which a queue is considered to be uncongested
static inline int queue_congestion_off_threshold(struct request_queue *q)
return q->nr_congestion_off;