[linux-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"
#include "blk-rq-qos.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,
	WBT_STATE_OFF_DEFAULT
};

struct rq_wb {
	/*
	 * Settings that govern how we throttle
	 */
	unsigned int wb_background;		/* background writeback */
	unsigned int wb_normal;			/* normal writeback */

	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 long last_issue;		/* last non-throttled issue */
	unsigned long last_comp;		/* last non-throttled comp */
	unsigned long min_lat_nsec;
	struct rq_qos rqos;
	struct rq_wait rq_wait[WBT_NUM_RWQ];
	struct rq_depth rq_depth;
};

static inline struct rq_wb *RQWB(struct rq_qos *rqos)
{
	return container_of(rqos, struct rq_wb, rqos);
}

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

int wbt_init(struct request_queue *);
void wbt_disable_default(struct request_queue *);
void wbt_enable_default(struct request_queue *);

u64 wbt_get_min_lat(struct request_queue *q);
void wbt_set_min_lat(struct request_queue *q, u64 val);

void wbt_set_write_cache(struct request_queue *, bool);

u64 wbt_default_latency_nsec(struct request_queue *);

#else

static inline int wbt_init(struct request_queue *q)
{
	return -EINVAL;
}
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_write_cache(struct request_queue *q, bool wc)
{
}
static inline u64 wbt_get_min_lat(struct request_queue *q)
{
	return 0;
}
static inline void wbt_set_min_lat(struct request_queue *q, u64 val)
{
}
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"
a7905043	12	#include "blk-rq-qos.h"
e34cbd30 JA	13
	14	enum wbt_flags {
	15	WBT_TRACKED = 1, /* write, tracked for throttling */
	16	WBT_READ = 2, /* read */
	17	WBT_KSWAPD = 4, /* write, from kswapd */
782f5697	18	WBT_DISCARD = 8, /* discard */
e34cbd30	19
782f5697	20	WBT_NR_BITS = 4, /* number of bits */
e34cbd30 JA	21	};
	22
	23	enum {
8bea6090 JA	24	WBT_RWQ_BG = 0,
8bea6090 JA	25	WBT_RWQ_KSWAPD,
782f5697	26	WBT_RWQ_DISCARD,
8bea6090	27	WBT_NUM_RWQ,
e34cbd30 JA	28	};
e34cbd30 JA	29
d62118b6 JA	30	/*
	31	* Enable states. Either off, or on by default (done at init time),
	32	* or on through manual setup in sysfs.
	33	*/
	34	enum {
	35	WBT_STATE_ON_DEFAULT = 1,
	36	WBT_STATE_ON_MANUAL = 2,
1d0903d6	37	WBT_STATE_OFF_DEFAULT
d62118b6 JA	38	};
d62118b6 JA	39
e34cbd30 JA	40	struct rq_wb {
	41	/*
	42	* Settings that govern how we throttle
	43	*/
	44	unsigned int wb_background; /* background writeback */
	45	unsigned int wb_normal; /* normal writeback */
e34cbd30	46
d62118b6 JA	47	short enable_state; /* WBT_STATE_* */
d62118b6 JA	48
e34cbd30 JA	49	/*
	50	* Number of consecutive periods where we don't have enough
	51	* information to make a firm scale up/down decision.
	52	*/
	53	unsigned int unknown_cnt;
	54
	55	u64 win_nsec; /* default window size */
	56	u64 cur_win_nsec; /* current window size */
	57
34dbad5d	58	struct blk_stat_callback *cb;
e34cbd30	59
544ccc8d	60	u64 sync_issue;
e34cbd30 JA	61	void *sync_cookie;
	62
	63	unsigned int wc;
e34cbd30 JA	64
	65	unsigned long last_issue; /* last non-throttled issue */
	66	unsigned long last_comp; /* last non-throttled comp */
	67	unsigned long min_lat_nsec;
a7905043	68	struct rq_qos rqos;
e34cbd30	69	struct rq_wait rq_wait[WBT_NUM_RWQ];
a7905043	70	struct rq_depth rq_depth;
e34cbd30 JA	71	};
e34cbd30 JA	72
a7905043 JB	73	static inline struct rq_wb RQWB(struct rq_qos rqos)
	74	{
	75	return container_of(rqos, struct rq_wb, rqos);
	76	}
	77
e34cbd30 JA	78	static inline unsigned int wbt_inflight(struct rq_wb *rwb)
	79	{
	80	unsigned int i, ret = 0;
	81
	82	for (i = 0; i < WBT_NUM_RWQ; i++)
	83	ret += atomic_read(&rwb->rq_wait[i].inflight);
	84
	85	return ret;
	86	}
	87
a7905043	88
e34cbd30 JA	89	#ifdef CONFIG_BLK_WBT
e34cbd30 JA	90
8054b89f	91	int wbt_init(struct request_queue *);
fa224eed	92	void wbt_disable_default(struct request_queue *);
8330cdb0	93	void wbt_enable_default(struct request_queue *);
e34cbd30	94
a7905043 JB	95	u64 wbt_get_min_lat(struct request_queue *q);
	96	void wbt_set_min_lat(struct request_queue *q, u64 val);
	97
a7905043	98	void wbt_set_write_cache(struct request_queue *, bool);
e34cbd30	99
80e091d1 JA	100	u64 wbt_default_latency_nsec(struct request_queue *);
80e091d1 JA	101
e34cbd30 JA	102	#else
e34cbd30 JA	103
8054b89f	104	static inline int wbt_init(struct request_queue *q)
e34cbd30 JA	105	{
	106	return -EINVAL;
	107	}
a7905043	108	static inline void wbt_disable_default(struct request_queue *q)
e34cbd30 JA	109	{
e34cbd30 JA	110	}
a7905043	111	static inline void wbt_enable_default(struct request_queue *q)
e34cbd30 JA	112	{
e34cbd30 JA	113	}
a7905043	114	static inline void wbt_set_write_cache(struct request_queue *q, bool wc)
8330cdb0 JK	115	{
8330cdb0 JK	116	}
a7905043	117	static inline u64 wbt_get_min_lat(struct request_queue *q)
e34cbd30	118	{
a7905043	119	return 0;
e34cbd30	120	}
a7905043	121	static inline void wbt_set_min_lat(struct request_queue *q, u64 val)
e34cbd30 JA	122	{
e34cbd30 JA	123	}
80e091d1 JA	124	static inline u64 wbt_default_latency_nsec(struct request_queue *q)
	125	{
	126	return 0;
	127	}
e34cbd30 JA	128
	129	#endif /* CONFIG_BLK_WBT */
	130
	131	#endif