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#ifndef WB_THROTTLE_H
#define WB_THROTTLE_H
#include <linux/atomic.h>
#include <linux/wait.h>
#include <linux/timer.h>
#include <linux/ktime.h>
#define ISSUE_STAT_MASK (1ULL << 63)
#define ISSUE_STAT_TIME_MASK ~ISSUE_STAT_MASK
struct wb_issue_stat {
u64 time;
};
static inline void wbt_issue_stat_set_time(struct wb_issue_stat *stat)
{
stat->time = (stat->time & ISSUE_STAT_MASK) |
(ktime_to_ns(ktime_get()) & ISSUE_STAT_TIME_MASK);
}
static inline u64 wbt_issue_stat_get_time(struct wb_issue_stat *stat)
{
return stat->time & ISSUE_STAT_TIME_MASK;
}
static inline void wbt_mark_tracked(struct wb_issue_stat *stat)
{
stat->time |= ISSUE_STAT_MASK;
}
static inline void wbt_clear_tracked(struct wb_issue_stat *stat)
{
stat->time &= ~ISSUE_STAT_MASK;
}
static inline bool wbt_tracked(struct wb_issue_stat *stat)
{
return (stat->time & ISSUE_STAT_MASK) != 0;
}
struct wb_stat_ops {
void (*get)(void *, struct blk_rq_stat *);
void (*clear)(void *);
};
struct rq_wb {
/*
* Settings that govern how we throttle
*/
unsigned int wb_background; /* background writeback */
unsigned int wb_normal; /* normal writeback */
unsigned int wb_max; /* max throughput writeback */
unsigned int scale_step;
u64 win_nsec; /* default window size */
u64 cur_win_nsec; /* current window size */
/*
* Number of consecutive periods where we don't have enough
* information to make a firm scale up/down decision.
*/
unsigned int unknown_cnt;
struct timer_list window_timer;
s64 sync_issue;
void *sync_cookie;
unsigned int wc;
unsigned int queue_depth;
unsigned long last_issue; /* last non-throttled issue */
unsigned long last_comp; /* last non-throttled comp */
unsigned long min_lat_nsec;
struct backing_dev_info *bdi;
struct request_queue *q;
wait_queue_head_t wait;
atomic_t inflight;
struct wb_stat_ops *stat_ops;
void *ops_data;
};
struct backing_dev_info;
void __wbt_done(struct rq_wb *);
void wbt_done(struct rq_wb *, struct wb_issue_stat *);
bool wbt_wait(struct rq_wb *, unsigned int, spinlock_t *);
struct rq_wb *wbt_init(struct backing_dev_info *, struct wb_stat_ops *, void *);
void wbt_exit(struct rq_wb *);
void wbt_update_limits(struct rq_wb *);
void wbt_requeue(struct rq_wb *, struct wb_issue_stat *);
void wbt_issue(struct rq_wb *, struct wb_issue_stat *);
void wbt_disable(struct rq_wb *);
void wbt_set_queue_depth(struct rq_wb *, unsigned int);
void wbt_set_write_cache(struct rq_wb *, bool);
#endif
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