[linux.git] / block / blk-wbt.h

/* SPDX-License-Identifier: GPL-2.0 */
#ifndef WB_THROTTLE_H
#define WB_THROTTLE_H

#include <linux/kernel.h>
#include <linux/atomic.h>
#include <linux/wait.h>
#include <linux/timer.h>
#include <linux/ktime.h>

#include "blk-stat.h"

enum wbt_flags {
	WBT_TRACKED		= 1,	/* write, tracked for throttling */
	WBT_READ		= 2,	/* read */
	WBT_KSWAPD		= 4,	/* write, from kswapd */

	WBT_NR_BITS		= 3,	/* number of bits */
};

enum {
	WBT_NUM_RWQ		= 2,
};

/*
 * Enable states. Either off, or on by default (done at init time),
 * or on through manual setup in sysfs.
 */
enum {
	WBT_STATE_ON_DEFAULT	= 1,
	WBT_STATE_ON_MANUAL	= 2,
};

static inline void wbt_clear_state(struct blk_issue_stat *stat)
{
	stat->stat &= ~BLK_STAT_RES_MASK;
}

static inline enum wbt_flags wbt_stat_to_mask(struct blk_issue_stat *stat)
{
	return (stat->stat & BLK_STAT_RES_MASK) >> BLK_STAT_RES_SHIFT;
}

static inline void wbt_track(struct blk_issue_stat *stat, enum wbt_flags wb_acct)
{
	stat->stat |= ((u64) wb_acct) << BLK_STAT_RES_SHIFT;
}

static inline bool wbt_is_tracked(struct blk_issue_stat *stat)
{
	return (stat->stat >> BLK_STAT_RES_SHIFT) & WBT_TRACKED;
}

static inline bool wbt_is_read(struct blk_issue_stat *stat)
{
	return (stat->stat >> BLK_STAT_RES_SHIFT) & WBT_READ;
}

struct rq_wait {
	wait_queue_head_t wait;
	atomic_t inflight;
};

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 */
	int scale_step;
	bool scaled_max;

	short enable_state;			/* WBT_STATE_* */

	/*
	 * Number of consecutive periods where we don't have enough
	 * information to make a firm scale up/down decision.
	 */
	unsigned int unknown_cnt;

	u64 win_nsec;				/* default window size */
	u64 cur_win_nsec;			/* current window size */

	struct blk_stat_callback *cb;

	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 request_queue *queue;
	struct rq_wait rq_wait[WBT_NUM_RWQ];
};

static inline unsigned int wbt_inflight(struct rq_wb *rwb)
{
	unsigned int i, ret = 0;

	for (i = 0; i < WBT_NUM_RWQ; i++)
		ret += atomic_read(&rwb->rq_wait[i].inflight);

	return ret;
}

#ifdef CONFIG_BLK_WBT

void __wbt_done(struct rq_wb *, enum wbt_flags);
void wbt_done(struct rq_wb *, struct blk_issue_stat *);
enum wbt_flags wbt_wait(struct rq_wb *, struct bio *, spinlock_t *);
int wbt_init(struct request_queue *);
void wbt_exit(struct request_queue *);
void wbt_update_limits(struct rq_wb *);
void wbt_requeue(struct rq_wb *, struct blk_issue_stat *);
void wbt_issue(struct rq_wb *, struct blk_issue_stat *);
void wbt_disable_default(struct request_queue *);
void wbt_enable_default(struct request_queue *);

void wbt_set_queue_depth(struct rq_wb *, unsigned int);
void wbt_set_write_cache(struct rq_wb *, bool);

u64 wbt_default_latency_nsec(struct request_queue *);

#else

static inline void __wbt_done(struct rq_wb *rwb, enum wbt_flags flags)
{
}
static inline void wbt_done(struct rq_wb *rwb, struct blk_issue_stat *stat)
{
}
static inline enum wbt_flags wbt_wait(struct rq_wb *rwb, struct bio *bio,
				      spinlock_t *lock)
{
	return 0;
}
static inline int wbt_init(struct request_queue *q)
{
	return -EINVAL;
}
static inline void wbt_exit(struct request_queue *q)
{
}
static inline void wbt_update_limits(struct rq_wb *rwb)
{
}
static inline void wbt_requeue(struct rq_wb *rwb, struct blk_issue_stat *stat)
{
}
static inline void wbt_issue(struct rq_wb *rwb, struct blk_issue_stat *stat)
{
}
static inline void wbt_disable_default(struct request_queue *q)
{
}
static inline void wbt_enable_default(struct request_queue *q)
{
}
static inline void wbt_set_queue_depth(struct rq_wb *rwb, unsigned int depth)
{
}
static inline void wbt_set_write_cache(struct rq_wb *rwb, bool wc)
{
}
static inline u64 wbt_default_latency_nsec(struct request_queue *q)
{
	return 0;
}

#endif /* CONFIG_BLK_WBT */

#endif
Commit	Line	Data
b2441318	1	/* SPDX-License-Identifier: GPL-2.0 */
e34cbd30 JA	2	#ifndef WB_THROTTLE_H
	3	#define WB_THROTTLE_H
	4
	5	#include <linux/kernel.h>
	6	#include <linux/atomic.h>
	7	#include <linux/wait.h>
	8	#include <linux/timer.h>
	9	#include <linux/ktime.h>
	10
	11	#include "blk-stat.h"
	12
	13	enum wbt_flags {
	14	WBT_TRACKED = 1, /* write, tracked for throttling */
	15	WBT_READ = 2, /* read */
	16	WBT_KSWAPD = 4, /* write, from kswapd */
	17
	18	WBT_NR_BITS = 3, /* number of bits */
	19	};
	20
	21	enum {
	22	WBT_NUM_RWQ = 2,
	23	};
	24
d62118b6 JA	25	/*
	26	* Enable states. Either off, or on by default (done at init time),
	27	* or on through manual setup in sysfs.
	28	*/
	29	enum {
	30	WBT_STATE_ON_DEFAULT = 1,
	31	WBT_STATE_ON_MANUAL = 2,
	32	};
	33
e34cbd30 JA	34	static inline void wbt_clear_state(struct blk_issue_stat *stat)
e34cbd30 JA	35	{
88eeca49	36	stat->stat &= ~BLK_STAT_RES_MASK;
e34cbd30 JA	37	}
	38
	39	static inline enum wbt_flags wbt_stat_to_mask(struct blk_issue_stat *stat)
	40	{
88eeca49	41	return (stat->stat & BLK_STAT_RES_MASK) >> BLK_STAT_RES_SHIFT;
e34cbd30 JA	42	}
	43
	44	static inline void wbt_track(struct blk_issue_stat *stat, enum wbt_flags wb_acct)
	45	{
88eeca49	46	stat->stat \|= ((u64) wb_acct) << BLK_STAT_RES_SHIFT;
e34cbd30 JA	47	}
	48
	49	static inline bool wbt_is_tracked(struct blk_issue_stat *stat)
	50	{
88eeca49	51	return (stat->stat >> BLK_STAT_RES_SHIFT) & WBT_TRACKED;
e34cbd30 JA	52	}
	53
	54	static inline bool wbt_is_read(struct blk_issue_stat *stat)
	55	{
88eeca49	56	return (stat->stat >> BLK_STAT_RES_SHIFT) & WBT_READ;
e34cbd30 JA	57	}
e34cbd30 JA	58
e34cbd30 JA	59	struct rq_wait {
	60	wait_queue_head_t wait;
	61	atomic_t inflight;
	62	};
	63
	64	struct rq_wb {
	65	/*
	66	* Settings that govern how we throttle
	67	*/
	68	unsigned int wb_background; /* background writeback */
	69	unsigned int wb_normal; /* normal writeback */
	70	unsigned int wb_max; /* max throughput writeback */
	71	int scale_step;
	72	bool scaled_max;
	73
d62118b6 JA	74	short enable_state; /* WBT_STATE_* */
d62118b6 JA	75
e34cbd30 JA	76	/*
	77	* Number of consecutive periods where we don't have enough
	78	* information to make a firm scale up/down decision.
	79	*/
	80	unsigned int unknown_cnt;
	81
	82	u64 win_nsec; /* default window size */
	83	u64 cur_win_nsec; /* current window size */
	84
34dbad5d	85	struct blk_stat_callback *cb;
e34cbd30 JA	86
	87	s64 sync_issue;
	88	void *sync_cookie;
	89
	90	unsigned int wc;
	91	unsigned int queue_depth;
	92
	93	unsigned long last_issue; /* last non-throttled issue */
	94	unsigned long last_comp; /* last non-throttled comp */
	95	unsigned long min_lat_nsec;
d8a0cbfd	96	struct request_queue *queue;
e34cbd30	97	struct rq_wait rq_wait[WBT_NUM_RWQ];
e34cbd30 JA	98	};
	99
	100	static inline unsigned int wbt_inflight(struct rq_wb *rwb)
	101	{
	102	unsigned int i, ret = 0;
	103
	104	for (i = 0; i < WBT_NUM_RWQ; i++)
	105	ret += atomic_read(&rwb->rq_wait[i].inflight);
	106
	107	return ret;
	108	}
	109
e34cbd30 JA	110	#ifdef CONFIG_BLK_WBT
	111
	112	void __wbt_done(struct rq_wb *, enum wbt_flags);
	113	void wbt_done(struct rq_wb , struct blk_issue_stat );
	114	enum wbt_flags wbt_wait(struct rq_wb , struct bio , spinlock_t *);
8054b89f	115	int wbt_init(struct request_queue *);
e34cbd30 JA	116	void wbt_exit(struct request_queue *);
	117	void wbt_update_limits(struct rq_wb *);
	118	void wbt_requeue(struct rq_wb , struct blk_issue_stat );
	119	void wbt_issue(struct rq_wb , struct blk_issue_stat );
fa224eed	120	void wbt_disable_default(struct request_queue *);
8330cdb0	121	void wbt_enable_default(struct request_queue *);
e34cbd30 JA	122
	123	void wbt_set_queue_depth(struct rq_wb *, unsigned int);
	124	void wbt_set_write_cache(struct rq_wb *, bool);
	125
80e091d1 JA	126	u64 wbt_default_latency_nsec(struct request_queue *);
80e091d1 JA	127
e34cbd30 JA	128	#else
	129
	130	static inline void __wbt_done(struct rq_wb *rwb, enum wbt_flags flags)
	131	{
	132	}
	133	static inline void wbt_done(struct rq_wb rwb, struct blk_issue_stat stat)
	134	{
	135	}
	136	static inline enum wbt_flags wbt_wait(struct rq_wb rwb, struct bio bio,
	137	spinlock_t *lock)
	138	{
	139	return 0;
	140	}
8054b89f	141	static inline int wbt_init(struct request_queue *q)
e34cbd30 JA	142	{
	143	return -EINVAL;
	144	}
	145	static inline void wbt_exit(struct request_queue *q)
	146	{
	147	}
	148	static inline void wbt_update_limits(struct rq_wb *rwb)
	149	{
	150	}
	151	static inline void wbt_requeue(struct rq_wb rwb, struct blk_issue_stat stat)
	152	{
	153	}
	154	static inline void wbt_issue(struct rq_wb rwb, struct blk_issue_stat stat)
	155	{
	156	}
fa224eed	157	static inline void wbt_disable_default(struct request_queue *q)
e34cbd30 JA	158	{
e34cbd30 JA	159	}
8330cdb0 JK	160	static inline void wbt_enable_default(struct request_queue *q)
	161	{
	162	}
e34cbd30 JA	163	static inline void wbt_set_queue_depth(struct rq_wb *rwb, unsigned int depth)
	164	{
	165	}
	166	static inline void wbt_set_write_cache(struct rq_wb *rwb, bool wc)
	167	{
	168	}
80e091d1 JA	169	static inline u64 wbt_default_latency_nsec(struct request_queue *q)
	170	{
	171	return 0;
	172	}
e34cbd30 JA	173
	174	#endif /* CONFIG_BLK_WBT */
	175
	176	#endif