diff options
Diffstat (limited to 'block/blk.h')
-rw-r--r-- | block/blk.h | 53 |
1 files changed, 53 insertions, 0 deletions
diff --git a/block/blk.h b/block/blk.h new file mode 100644 index 00000000000..ec898dd0c65 --- /dev/null +++ b/block/blk.h @@ -0,0 +1,53 @@ +#ifndef BLK_INTERNAL_H +#define BLK_INTERNAL_H + +/* 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); + +/* + * 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; +} + +#endif |