LXR linux/block/blk-rq-qos.h

   1#ifndef RQ_QOS_H
   2#define RQ_QOS_H
   3
   4#include <linux/kernel.h>
   5#include <linux/blkdev.h>
   6#include <linux/blk_types.h>
   7#include <linux/atomic.h>
   8#include <linux/wait.h>
   9
  10enum rq_qos_id {
  11        RQ_QOS_WBT,
  12        RQ_QOS_CGROUP,
  13};
  14
  15struct rq_wait {
  16        wait_queue_head_t wait;
  17        atomic_t inflight;
  18};
  19
  20struct rq_qos {
  21        struct rq_qos_ops *ops;
  22        struct request_queue *q;
  23        enum rq_qos_id id;
  24        struct rq_qos *next;
  25};
  26
  27struct rq_qos_ops {
  28        void (*throttle)(struct rq_qos *, struct bio *, spinlock_t *);
  29        void (*track)(struct rq_qos *, struct request *, struct bio *);
  30        void (*issue)(struct rq_qos *, struct request *);
  31        void (*requeue)(struct rq_qos *, struct request *);
  32        void (*done)(struct rq_qos *, struct request *);
  33        void (*done_bio)(struct rq_qos *, struct bio *);
  34        void (*cleanup)(struct rq_qos *, struct bio *);
  35        void (*exit)(struct rq_qos *);
  36};
  37
  38struct rq_depth {
  39        unsigned int max_depth;
  40
  41        int scale_step;
  42        bool scaled_max;
  43
  44        unsigned int queue_depth;
  45        unsigned int default_depth;
  46};
  47
  48static inline struct rq_qos *rq_qos_id(struct request_queue *q,
  49                                       enum rq_qos_id id)
  50{
  51        struct rq_qos *rqos;
  52        for (rqos = q->rq_qos; rqos; rqos = rqos->next) {
  53                if (rqos->id == id)
  54                        break;
  55        }
  56        return rqos;
  57}
  58
  59static inline struct rq_qos *wbt_rq_qos(struct request_queue *q)
  60{
  61        return rq_qos_id(q, RQ_QOS_WBT);
  62}
  63
  64static inline struct rq_qos *blkcg_rq_qos(struct request_queue *q)
  65{
  66        return rq_qos_id(q, RQ_QOS_CGROUP);
  67}
  68
  69static inline void rq_wait_init(struct rq_wait *rq_wait)
  70{
  71        atomic_set(&rq_wait->inflight, 0);
  72        init_waitqueue_head(&rq_wait->wait);
  73}
  74
  75static inline void rq_qos_add(struct request_queue *q, struct rq_qos *rqos)
  76{
  77        rqos->next = q->rq_qos;
  78        q->rq_qos = rqos;
  79}
  80
  81static inline void rq_qos_del(struct request_queue *q, struct rq_qos *rqos)
  82{
  83        struct rq_qos *cur, *prev = NULL;
  84        for (cur = q->rq_qos; cur; cur = cur->next) {
  85                if (cur == rqos) {
  86                        if (prev)
  87                                prev->next = rqos->next;
  88                        else
  89                                q->rq_qos = cur;
  90                        break;
  91                }
  92                prev = cur;
  93        }
  94}
  95
  96bool rq_wait_inc_below(struct rq_wait *rq_wait, unsigned int limit);
  97void rq_depth_scale_up(struct rq_depth *rqd);
  98void rq_depth_scale_down(struct rq_depth *rqd, bool hard_throttle);
  99bool rq_depth_calc_max_depth(struct rq_depth *rqd);
 100
 101void rq_qos_cleanup(struct request_queue *, struct bio *);
 102void rq_qos_done(struct request_queue *, struct request *);
 103void rq_qos_issue(struct request_queue *, struct request *);
 104void rq_qos_requeue(struct request_queue *, struct request *);
 105void rq_qos_done_bio(struct request_queue *q, struct bio *bio);
 106void rq_qos_throttle(struct request_queue *, struct bio *, spinlock_t *);
 107void rq_qos_track(struct request_queue *q, struct request *, struct bio *);
 108void rq_qos_exit(struct request_queue *);
 109#endif
 110