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
  10 enum rq_qos_id {
  11         RQ_QOS_WBT,
  12         RQ_QOS_CGROUP,
  13 };
  14
  15 struct rq_wait {
  16         wait_queue_head_t wait;
  17         atomic_t inflight;
  18 };
  19
  20 struct 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
  27 struct 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
  38 struct 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
  48 static 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
  59 static inline struct rq_qos *wbt_rq_qos(struct request_queue *q)
  60 {
  61         return rq_qos_id(q, RQ_QOS_WBT);
  62 }
  63
  64 static inline struct rq_qos *blkcg_rq_qos(struct request_queue *q)
  65 {
  66         return rq_qos_id(q, RQ_QOS_CGROUP);
  67 }
  68
  69 static 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
  75 static 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
  81 static 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
  96 bool rq_wait_inc_below(struct rq_wait *rq_wait, unsigned int limit);
  97 void rq_depth_scale_up(struct rq_depth *rqd);
  98 void rq_depth_scale_down(struct rq_depth *rqd, bool hard_throttle);
  99 bool rq_depth_calc_max_depth(struct rq_depth *rqd);
 100
 101 void rq_qos_cleanup(struct request_queue *, struct bio *);
 102 void rq_qos_done(struct request_queue *, struct request *);
 103 void rq_qos_issue(struct request_queue *, struct request *);
 104 void rq_qos_requeue(struct request_queue *, struct request *);
 105 void rq_qos_done_bio(struct request_queue *q, struct bio *bio);
 106 void rq_qos_throttle(struct request_queue *, struct bio *, spinlock_t *);
 107 void rq_qos_track(struct request_queue *q, struct request *, struct bio *);
 108 void rq_qos_exit(struct request_queue *);
 109 #endif