[mirror_ubuntu-bionic-kernel.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_RWQ_BG		= 0,
	WBT_RWQ_KSWAPD,
	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,
};

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 {
d9204a0b JA	22	WBT_RWQ_BG = 0,
	23	WBT_RWQ_KSWAPD,
	24	WBT_NUM_RWQ,
e34cbd30 JA	25	};
e34cbd30 JA	26
d62118b6 JA	27	/*
	28	* Enable states. Either off, or on by default (done at init time),
	29	* or on through manual setup in sysfs.
	30	*/
	31	enum {
	32	WBT_STATE_ON_DEFAULT = 1,
	33	WBT_STATE_ON_MANUAL = 2,
	34	};
	35
e34cbd30 JA	36	static inline void wbt_clear_state(struct blk_issue_stat *stat)
e34cbd30 JA	37	{
88eeca49	38	stat->stat &= ~BLK_STAT_RES_MASK;
e34cbd30 JA	39	}
	40
	41	static inline enum wbt_flags wbt_stat_to_mask(struct blk_issue_stat *stat)
	42	{
88eeca49	43	return (stat->stat & BLK_STAT_RES_MASK) >> BLK_STAT_RES_SHIFT;
e34cbd30 JA	44	}
	45
	46	static inline void wbt_track(struct blk_issue_stat *stat, enum wbt_flags wb_acct)
	47	{
88eeca49	48	stat->stat \|= ((u64) wb_acct) << BLK_STAT_RES_SHIFT;
e34cbd30 JA	49	}
	50
	51	static inline bool wbt_is_tracked(struct blk_issue_stat *stat)
	52	{
88eeca49	53	return (stat->stat >> BLK_STAT_RES_SHIFT) & WBT_TRACKED;
e34cbd30 JA	54	}
	55
	56	static inline bool wbt_is_read(struct blk_issue_stat *stat)
	57	{
88eeca49	58	return (stat->stat >> BLK_STAT_RES_SHIFT) & WBT_READ;
e34cbd30 JA	59	}
e34cbd30 JA	60
e34cbd30 JA	61	struct rq_wait {
	62	wait_queue_head_t wait;
	63	atomic_t inflight;
	64	};
	65
	66	struct rq_wb {
	67	/*
	68	* Settings that govern how we throttle
	69	*/
	70	unsigned int wb_background; /* background writeback */
	71	unsigned int wb_normal; /* normal writeback */
	72	unsigned int wb_max; /* max throughput writeback */
	73	int scale_step;
	74	bool scaled_max;
	75
d62118b6 JA	76	short enable_state; /* WBT_STATE_* */
d62118b6 JA	77
e34cbd30 JA	78	/*
	79	* Number of consecutive periods where we don't have enough
	80	* information to make a firm scale up/down decision.
	81	*/
	82	unsigned int unknown_cnt;
	83
	84	u64 win_nsec; /* default window size */
	85	u64 cur_win_nsec; /* current window size */
	86
34dbad5d	87	struct blk_stat_callback *cb;
e34cbd30 JA	88
	89	s64 sync_issue;
	90	void *sync_cookie;
	91
	92	unsigned int wc;
	93	unsigned int queue_depth;
	94
	95	unsigned long last_issue; /* last non-throttled issue */
	96	unsigned long last_comp; /* last non-throttled comp */
	97	unsigned long min_lat_nsec;
d8a0cbfd	98	struct request_queue *queue;
e34cbd30	99	struct rq_wait rq_wait[WBT_NUM_RWQ];
e34cbd30 JA	100	};
	101
	102	static inline unsigned int wbt_inflight(struct rq_wb *rwb)
	103	{
	104	unsigned int i, ret = 0;
	105
	106	for (i = 0; i < WBT_NUM_RWQ; i++)
	107	ret += atomic_read(&rwb->rq_wait[i].inflight);
	108
	109	return ret;
	110	}
	111
e34cbd30 JA	112	#ifdef CONFIG_BLK_WBT
	113
	114	void __wbt_done(struct rq_wb *, enum wbt_flags);
	115	void wbt_done(struct rq_wb , struct blk_issue_stat );
	116	enum wbt_flags wbt_wait(struct rq_wb , struct bio , spinlock_t *);
8054b89f	117	int wbt_init(struct request_queue *);
e34cbd30 JA	118	void wbt_exit(struct request_queue *);
	119	void wbt_update_limits(struct rq_wb *);
	120	void wbt_requeue(struct rq_wb , struct blk_issue_stat );
	121	void wbt_issue(struct rq_wb , struct blk_issue_stat );
fa224eed	122	void wbt_disable_default(struct request_queue *);
8330cdb0	123	void wbt_enable_default(struct request_queue *);
e34cbd30 JA	124
	125	void wbt_set_queue_depth(struct rq_wb *, unsigned int);
	126	void wbt_set_write_cache(struct rq_wb *, bool);
	127
80e091d1 JA	128	u64 wbt_default_latency_nsec(struct request_queue *);
80e091d1 JA	129
e34cbd30 JA	130	#else
	131
	132	static inline void __wbt_done(struct rq_wb *rwb, enum wbt_flags flags)
	133	{
	134	}
	135	static inline void wbt_done(struct rq_wb rwb, struct blk_issue_stat stat)
	136	{
	137	}
	138	static inline enum wbt_flags wbt_wait(struct rq_wb rwb, struct bio bio,
	139	spinlock_t *lock)
	140	{
	141	return 0;
	142	}
8054b89f	143	static inline int wbt_init(struct request_queue *q)
e34cbd30 JA	144	{
	145	return -EINVAL;
	146	}
	147	static inline void wbt_exit(struct request_queue *q)
	148	{
	149	}
	150	static inline void wbt_update_limits(struct rq_wb *rwb)
	151	{
	152	}
	153	static inline void wbt_requeue(struct rq_wb rwb, struct blk_issue_stat stat)
	154	{
	155	}
	156	static inline void wbt_issue(struct rq_wb rwb, struct blk_issue_stat stat)
	157	{
	158	}
fa224eed	159	static inline void wbt_disable_default(struct request_queue *q)
e34cbd30 JA	160	{
e34cbd30 JA	161	}
8330cdb0 JK	162	static inline void wbt_enable_default(struct request_queue *q)
	163	{
	164	}
e34cbd30 JA	165	static inline void wbt_set_queue_depth(struct rq_wb *rwb, unsigned int depth)
	166	{
	167	}
	168	static inline void wbt_set_write_cache(struct rq_wb *rwb, bool wc)
	169	{
	170	}
80e091d1 JA	171	static inline u64 wbt_default_latency_nsec(struct request_queue *q)
	172	{
	173	return 0;
	174	}
e34cbd30 JA	175
	176	#endif /* CONFIG_BLK_WBT */
	177
	178	#endif