[linux-2.6-block.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_DISCARD		= 8,	/* discard */

	WBT_NR_BITS		= 4,	/* number of bits */
};

enum {
	WBT_RWQ_BG		= 0,
	WBT_RWQ_KSWAPD,
	WBT_RWQ_DISCARD,
	WBT_NUM_RWQ,
};

/*
 * 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,
};

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;

	u64 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

static inline void wbt_track(struct request *rq, enum wbt_flags flags)
{
	rq->wbt_flags |= flags;
}

void __wbt_done(struct rq_wb *, enum wbt_flags);
void wbt_done(struct rq_wb *, struct request *);
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 request *);
void wbt_issue(struct rq_wb *, struct request *);
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_track(struct request *rq, enum wbt_flags flags)
{
}
static inline void __wbt_done(struct rq_wb *rwb, enum wbt_flags flags)
{
}
static inline void wbt_done(struct rq_wb *rwb, struct request *rq)
{
}
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 request *rq)
{
}
static inline void wbt_issue(struct rq_wb *rwb, struct request *rq)
{
}
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 */
782f5697	17	WBT_DISCARD = 8, /* discard */
e34cbd30	18
782f5697	19	WBT_NR_BITS = 4, /* number of bits */
e34cbd30 JA	20	};
	21
	22	enum {
8bea6090 JA	23	WBT_RWQ_BG = 0,
8bea6090 JA	24	WBT_RWQ_KSWAPD,
782f5697	25	WBT_RWQ_DISCARD,
8bea6090	26	WBT_NUM_RWQ,
e34cbd30 JA	27	};
e34cbd30 JA	28
d62118b6 JA	29	/*
	30	* Enable states. Either off, or on by default (done at init time),
	31	* or on through manual setup in sysfs.
	32	*/
	33	enum {
	34	WBT_STATE_ON_DEFAULT = 1,
	35	WBT_STATE_ON_MANUAL = 2,
	36	};
	37
e34cbd30 JA	38	struct rq_wait {
	39	wait_queue_head_t wait;
	40	atomic_t inflight;
	41	};
	42
	43	struct rq_wb {
	44	/*
	45	* Settings that govern how we throttle
	46	*/
	47	unsigned int wb_background; /* background writeback */
	48	unsigned int wb_normal; /* normal writeback */
	49	unsigned int wb_max; /* max throughput writeback */
	50	int scale_step;
	51	bool scaled_max;
	52
d62118b6 JA	53	short enable_state; /* WBT_STATE_* */
d62118b6 JA	54
e34cbd30 JA	55	/*
	56	* Number of consecutive periods where we don't have enough
	57	* information to make a firm scale up/down decision.
	58	*/
	59	unsigned int unknown_cnt;
	60
	61	u64 win_nsec; /* default window size */
	62	u64 cur_win_nsec; /* current window size */
	63
34dbad5d	64	struct blk_stat_callback *cb;
e34cbd30	65
544ccc8d	66	u64 sync_issue;
e34cbd30 JA	67	void *sync_cookie;
	68
	69	unsigned int wc;
	70	unsigned int queue_depth;
	71
	72	unsigned long last_issue; /* last non-throttled issue */
	73	unsigned long last_comp; /* last non-throttled comp */
	74	unsigned long min_lat_nsec;
d8a0cbfd	75	struct request_queue *queue;
e34cbd30	76	struct rq_wait rq_wait[WBT_NUM_RWQ];
e34cbd30 JA	77	};
	78
	79	static inline unsigned int wbt_inflight(struct rq_wb *rwb)
	80	{
	81	unsigned int i, ret = 0;
	82
	83	for (i = 0; i < WBT_NUM_RWQ; i++)
	84	ret += atomic_read(&rwb->rq_wait[i].inflight);
	85
	86	return ret;
	87	}
	88
e34cbd30 JA	89	#ifdef CONFIG_BLK_WBT
e34cbd30 JA	90
a8a45941	91	static inline void wbt_track(struct request *rq, enum wbt_flags flags)
934031a1	92	{
544ccc8d	93	rq->wbt_flags \|= flags;
934031a1 OS	94	}
934031a1 OS	95
e34cbd30	96	void __wbt_done(struct rq_wb *, enum wbt_flags);
a8a45941	97	void wbt_done(struct rq_wb , struct request );
e34cbd30	98	enum wbt_flags wbt_wait(struct rq_wb , struct bio , spinlock_t *);
8054b89f	99	int wbt_init(struct request_queue *);
e34cbd30 JA	100	void wbt_exit(struct request_queue *);
e34cbd30 JA	101	void wbt_update_limits(struct rq_wb *);
a8a45941 OS	102	void wbt_requeue(struct rq_wb , struct request );
a8a45941 OS	103	void wbt_issue(struct rq_wb , struct request );
fa224eed	104	void wbt_disable_default(struct request_queue *);
8330cdb0	105	void wbt_enable_default(struct request_queue *);
e34cbd30 JA	106
	107	void wbt_set_queue_depth(struct rq_wb *, unsigned int);
	108	void wbt_set_write_cache(struct rq_wb *, bool);
	109
80e091d1 JA	110	u64 wbt_default_latency_nsec(struct request_queue *);
80e091d1 JA	111
e34cbd30 JA	112	#else
e34cbd30 JA	113
a8a45941	114	static inline void wbt_track(struct request *rq, enum wbt_flags flags)
934031a1 OS	115	{
934031a1 OS	116	}
e34cbd30 JA	117	static inline void __wbt_done(struct rq_wb *rwb, enum wbt_flags flags)
	118	{
	119	}
a8a45941	120	static inline void wbt_done(struct rq_wb rwb, struct request rq)
e34cbd30 JA	121	{
	122	}
	123	static inline enum wbt_flags wbt_wait(struct rq_wb rwb, struct bio bio,
	124	spinlock_t *lock)
	125	{
	126	return 0;
	127	}
8054b89f	128	static inline int wbt_init(struct request_queue *q)
e34cbd30 JA	129	{
	130	return -EINVAL;
	131	}
	132	static inline void wbt_exit(struct request_queue *q)
	133	{
	134	}
	135	static inline void wbt_update_limits(struct rq_wb *rwb)
	136	{
	137	}
a8a45941	138	static inline void wbt_requeue(struct rq_wb rwb, struct request rq)
e34cbd30 JA	139	{
e34cbd30 JA	140	}
a8a45941	141	static inline void wbt_issue(struct rq_wb rwb, struct request rq)
e34cbd30 JA	142	{
e34cbd30 JA	143	}
fa224eed	144	static inline void wbt_disable_default(struct request_queue *q)
e34cbd30 JA	145	{
e34cbd30 JA	146	}
8330cdb0 JK	147	static inline void wbt_enable_default(struct request_queue *q)
	148	{
	149	}
e34cbd30 JA	150	static inline void wbt_set_queue_depth(struct rq_wb *rwb, unsigned int depth)
	151	{
	152	}
	153	static inline void wbt_set_write_cache(struct rq_wb *rwb, bool wc)
	154	{
	155	}
80e091d1 JA	156	static inline u64 wbt_default_latency_nsec(struct request_queue *q)
	157	{
	158	return 0;
	159	}
e34cbd30 JA	160
	161	#endif /* CONFIG_BLK_WBT */
	162
	163	#endif