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alistair23-linux/block/blk-rq-qos.h

107 lines
2.4 KiB
C

#ifndef RQ_QOS_H
#define RQ_QOS_H
#include <linux/kernel.h>
#include <linux/blkdev.h>
#include <linux/blk_types.h>
#include <linux/atomic.h>
#include <linux/wait.h>
enum rq_qos_id {
RQ_QOS_WBT,
RQ_QOS_CGROUP,
};
struct rq_wait {
wait_queue_head_t wait;
atomic_t inflight;
};
struct rq_qos {
struct rq_qos_ops *ops;
struct request_queue *q;
enum rq_qos_id id;
struct rq_qos *next;
};
struct rq_qos_ops {
enum wbt_flags (*throttle)(struct rq_qos *, struct bio *,
spinlock_t *);
void (*issue)(struct rq_qos *, struct request *);
void (*requeue)(struct rq_qos *, struct request *);
void (*done)(struct rq_qos *, struct request *);
void (*cleanup)(struct rq_qos *, enum wbt_flags);
void (*exit)(struct rq_qos *);
};
struct rq_depth {
unsigned int max_depth;
int scale_step;
bool scaled_max;
unsigned int queue_depth;
unsigned int default_depth;
};
static inline struct rq_qos *rq_qos_id(struct request_queue *q,
enum rq_qos_id id)
{
struct rq_qos *rqos;
for (rqos = q->rq_qos; rqos; rqos = rqos->next) {
if (rqos->id == id)
break;
}
return rqos;
}
static inline struct rq_qos *wbt_rq_qos(struct request_queue *q)
{
return rq_qos_id(q, RQ_QOS_WBT);
}
static inline struct rq_qos *blkcg_rq_qos(struct request_queue *q)
{
return rq_qos_id(q, RQ_QOS_CGROUP);
}
static inline void rq_wait_init(struct rq_wait *rq_wait)
{
atomic_set(&rq_wait->inflight, 0);
init_waitqueue_head(&rq_wait->wait);
}
static inline void rq_qos_add(struct request_queue *q, struct rq_qos *rqos)
{
rqos->next = q->rq_qos;
q->rq_qos = rqos;
}
static inline void rq_qos_del(struct request_queue *q, struct rq_qos *rqos)
{
struct rq_qos *cur, *prev = NULL;
for (cur = q->rq_qos; cur; cur = cur->next) {
if (cur == rqos) {
if (prev)
prev->next = rqos->next;
else
q->rq_qos = cur;
break;
}
prev = cur;
}
}
bool rq_wait_inc_below(struct rq_wait *rq_wait, int limit);
void rq_depth_scale_up(struct rq_depth *rqd);
void rq_depth_scale_down(struct rq_depth *rqd, bool hard_throttle);
bool rq_depth_calc_max_depth(struct rq_depth *rqd);
void rq_qos_cleanup(struct request_queue *, enum wbt_flags);
void rq_qos_done(struct request_queue *, struct request *);
void rq_qos_issue(struct request_queue *, struct request *);
void rq_qos_requeue(struct request_queue *, struct request *);
enum wbt_flags rq_qos_throttle(struct request_queue *, struct bio *, spinlock_t *);
void rq_qos_exit(struct request_queue *);
#endif