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 #include "blk-mq-debugfs.h"
  11
  12 struct blk_mq_debugfs_attr;
  13
  14 enum rq_qos_id {
  15         RQ_QOS_WBT,
  16         RQ_QOS_CGROUP,
  17 };
  18
  19 struct rq_wait {
  20         wait_queue_head_t wait;
  21         atomic_t inflight;
  22 };
  23
  24 struct rq_qos {
  25         struct rq_qos_ops *ops;
  26         struct request_queue *q;
  27         enum rq_qos_id id;
  28         struct rq_qos *next;
  29 #ifdef CONFIG_BLK_DEBUG_FS
  30         struct dentry *debugfs_dir;
  31 #endif
  32 };
  33
  34 struct rq_qos_ops {
  35         void (*throttle)(struct rq_qos *, struct bio *);
  36         void (*track)(struct rq_qos *, struct request *, struct bio *);
  37         void (*issue)(struct rq_qos *, struct request *);
  38         void (*requeue)(struct rq_qos *, struct request *);
  39         void (*done)(struct rq_qos *, struct request *);
  40         void (*done_bio)(struct rq_qos *, struct bio *);
  41         void (*cleanup)(struct rq_qos *, struct bio *);
  42         void (*exit)(struct rq_qos *);
  43         const struct blk_mq_debugfs_attr *debugfs_attrs;
  44 };
  45
  46 struct rq_depth {
  47         unsigned int max_depth;
  48
  49         int scale_step;
  50         bool scaled_max;
  51
  52         unsigned int queue_depth;
  53         unsigned int default_depth;
  54 };
  55
  56 static inline struct rq_qos *rq_qos_id(struct request_queue *q,
  57                                        enum rq_qos_id id)
  58 {
  59         struct rq_qos *rqos;
  60         for (rqos = q->rq_qos; rqos; rqos = rqos->next) {
  61                 if (rqos->id == id)
  62                         break;
  63         }
  64         return rqos;
  65 }
  66
  67 static inline struct rq_qos *wbt_rq_qos(struct request_queue *q)
  68 {
  69         return rq_qos_id(q, RQ_QOS_WBT);
  70 }
  71
  72 static inline struct rq_qos *blkcg_rq_qos(struct request_queue *q)
  73 {
  74         return rq_qos_id(q, RQ_QOS_CGROUP);
  75 }
  76
  77 static inline const char *rq_qos_id_to_name(enum rq_qos_id id)
  78 {
  79         switch (id) {
  80         case RQ_QOS_WBT:
  81                 return "wbt";
  82         case RQ_QOS_CGROUP:
  83                 return "cgroup";
  84         }
  85         return "unknown";
  86 }
  87
  88 static inline void rq_wait_init(struct rq_wait *rq_wait)
  89 {
  90         atomic_set(&rq_wait->inflight, 0);
  91         init_waitqueue_head(&rq_wait->wait);
  92 }
  93
  94 static inline void rq_qos_add(struct request_queue *q, struct rq_qos *rqos)
  95 {
  96         rqos->next = q->rq_qos;
  97         q->rq_qos = rqos;
  98
  99         if (rqos->ops->debugfs_attrs)
 100                 blk_mq_debugfs_register_rqos(rqos);
 101 }
 102
 103 static inline void rq_qos_del(struct request_queue *q, struct rq_qos *rqos)
 104 {
 105         struct rq_qos *cur, *prev = NULL;
 106         for (cur = q->rq_qos; cur; cur = cur->next) {
 107                 if (cur == rqos) {
 108                         if (prev)
 109                                 prev->next = rqos->next;
 110                         else
 111                                 q->rq_qos = cur;
 112                         break;
 113                 }
 114                 prev = cur;
 115         }
 116
 117         blk_mq_debugfs_unregister_rqos(rqos);
 118 }
 119
 120 typedef bool (acquire_inflight_cb_t)(struct rq_wait *rqw, void *private_data);
 121 typedef void (cleanup_cb_t)(struct rq_wait *rqw, void *private_data);
 122
 123 void rq_qos_wait(struct rq_wait *rqw, void *private_data,
 124                  acquire_inflight_cb_t *acquire_inflight_cb,
 125                  cleanup_cb_t *cleanup_cb);
 126 bool rq_wait_inc_below(struct rq_wait *rq_wait, unsigned int limit);
 127 void rq_depth_scale_up(struct rq_depth *rqd);
 128 void rq_depth_scale_down(struct rq_depth *rqd, bool hard_throttle);
 129 bool rq_depth_calc_max_depth(struct rq_depth *rqd);
 130
 131 void __rq_qos_cleanup(struct rq_qos *rqos, struct bio *bio);
 132 void __rq_qos_done(struct rq_qos *rqos, struct request *rq);
 133 void __rq_qos_issue(struct rq_qos *rqos, struct request *rq);
 134 void __rq_qos_requeue(struct rq_qos *rqos, struct request *rq);
 135 void __rq_qos_throttle(struct rq_qos *rqos, struct bio *bio);
 136 void __rq_qos_track(struct rq_qos *rqos, struct request *rq, struct bio *bio);
 137 void __rq_qos_done_bio(struct rq_qos *rqos, struct bio *bio);
 138
 139 static inline void rq_qos_cleanup(struct request_queue *q, struct bio *bio)
 140 {
 141         if (q->rq_qos)
 142                 __rq_qos_cleanup(q->rq_qos, bio);
 143 }
 144
 145 static inline void rq_qos_done(struct request_queue *q, struct request *rq)
 146 {
 147         if (q->rq_qos)
 148                 __rq_qos_done(q->rq_qos, rq);
 149 }
 150
 151 static inline void rq_qos_issue(struct request_queue *q, struct request *rq)
 152 {
 153         if (q->rq_qos)
 154                 __rq_qos_issue(q->rq_qos, rq);
 155 }
 156
 157 static inline void rq_qos_requeue(struct request_queue *q, struct request *rq)
 158 {
 159         if (q->rq_qos)
 160                 __rq_qos_requeue(q->rq_qos, rq);
 161 }
 162
 163 static inline void rq_qos_done_bio(struct request_queue *q, struct bio *bio)
 164 {
 165         if (q->rq_qos)
 166                 __rq_qos_done_bio(q->rq_qos, bio);
 167 }
 168
 169 static inline void rq_qos_throttle(struct request_queue *q, struct bio *bio)
 170 {
 171         /*
 172          * BIO_TRACKED lets controllers know that a bio went through the
 173          * normal rq_qos path.
 174          */
 175         bio_set_flag(bio, BIO_TRACKED);
 176         if (q->rq_qos)
 177                 __rq_qos_throttle(q->rq_qos, bio);
 178 }
 179
 180 static inline void rq_qos_track(struct request_queue *q, struct request *rq,
 181                                 struct bio *bio)
 182 {
 183         if (q->rq_qos)
 184                 __rq_qos_track(q->rq_qos, rq, bio);
 185 }
 186
 187 void rq_qos_exit(struct request_queue *);
 188
 189 #endif