[deliverable/linux.git] / block / blk-cgroup.h

#ifndef _BLK_CGROUP_H
#define _BLK_CGROUP_H
/*
 * Common Block IO controller cgroup interface
 *
 * Based on ideas and code from CFQ, CFS and BFQ:
 * Copyright (C) 2003 Jens Axboe <axboe@kernel.dk>
 *
 * Copyright (C) 2008 Fabio Checconi <fabio@gandalf.sssup.it>
 *		      Paolo Valente <paolo.valente@unimore.it>
 *
 * Copyright (C) 2009 Vivek Goyal <vgoyal@redhat.com>
 * 	              Nauman Rafique <nauman@google.com>
 */

#include <linux/cgroup.h>
#include <linux/u64_stats_sync.h>

enum blkio_policy_id {
	BLKIO_POLICY_PROP = 0,		/* Proportional Bandwidth division */
	BLKIO_POLICY_THROTL,		/* Throttling */
};

/* Max limits for throttle policy */
#define THROTL_IOPS_MAX		UINT_MAX

#if defined(CONFIG_BLK_CGROUP) || defined(CONFIG_BLK_CGROUP_MODULE)

#ifndef CONFIG_BLK_CGROUP
/* When blk-cgroup is a module, its subsys_id isn't a compile-time constant */
extern struct cgroup_subsys blkio_subsys;
#define blkio_subsys_id blkio_subsys.subsys_id
#endif

enum stat_type {
	/* Total time spent (in ns) between request dispatch to the driver and
	 * request completion for IOs doen by this cgroup. This may not be
	 * accurate when NCQ is turned on. */
	BLKIO_STAT_SERVICE_TIME = 0,
	/* Total time spent waiting in scheduler queue in ns */
	BLKIO_STAT_WAIT_TIME,
	/* Number of IOs queued up */
	BLKIO_STAT_QUEUED,
	/* All the single valued stats go below this */
	BLKIO_STAT_TIME,
#ifdef CONFIG_DEBUG_BLK_CGROUP
	/* Time not charged to this cgroup */
	BLKIO_STAT_UNACCOUNTED_TIME,
	BLKIO_STAT_AVG_QUEUE_SIZE,
	BLKIO_STAT_IDLE_TIME,
	BLKIO_STAT_EMPTY_TIME,
	BLKIO_STAT_GROUP_WAIT_TIME,
	BLKIO_STAT_DEQUEUE
#endif
};

/* Per cpu stats */
enum stat_type_cpu {
	BLKIO_STAT_CPU_SECTORS,
	/* Total bytes transferred */
	BLKIO_STAT_CPU_SERVICE_BYTES,
	/* Total IOs serviced, post merge */
	BLKIO_STAT_CPU_SERVICED,
	/* Number of IOs merged */
	BLKIO_STAT_CPU_MERGED,
	BLKIO_STAT_CPU_NR
};

enum stat_sub_type {
	BLKIO_STAT_READ = 0,
	BLKIO_STAT_WRITE,
	BLKIO_STAT_SYNC,
	BLKIO_STAT_ASYNC,
	BLKIO_STAT_TOTAL
};

/* blkg state flags */
enum blkg_state_flags {
	BLKG_waiting = 0,
	BLKG_idling,
	BLKG_empty,
};

/* cgroup files owned by proportional weight policy */
enum blkcg_file_name_prop {
	BLKIO_PROP_weight = 1,
	BLKIO_PROP_weight_device,
	BLKIO_PROP_io_service_bytes,
	BLKIO_PROP_io_serviced,
	BLKIO_PROP_time,
	BLKIO_PROP_sectors,
	BLKIO_PROP_unaccounted_time,
	BLKIO_PROP_io_service_time,
	BLKIO_PROP_io_wait_time,
	BLKIO_PROP_io_merged,
	BLKIO_PROP_io_queued,
	BLKIO_PROP_avg_queue_size,
	BLKIO_PROP_group_wait_time,
	BLKIO_PROP_idle_time,
	BLKIO_PROP_empty_time,
	BLKIO_PROP_dequeue,
};

/* cgroup files owned by throttle policy */
enum blkcg_file_name_throtl {
	BLKIO_THROTL_read_bps_device,
	BLKIO_THROTL_write_bps_device,
	BLKIO_THROTL_read_iops_device,
	BLKIO_THROTL_write_iops_device,
	BLKIO_THROTL_io_service_bytes,
	BLKIO_THROTL_io_serviced,
};

struct blkio_cgroup {
	struct cgroup_subsys_state css;
	unsigned int weight;
	spinlock_t lock;
	struct hlist_head blkg_list;
	struct list_head policy_list; /* list of blkio_policy_node */
};

struct blkio_group_stats {
	/* total disk time and nr sectors dispatched by this group */
	uint64_t time;
	uint64_t stat_arr[BLKIO_STAT_QUEUED + 1][BLKIO_STAT_TOTAL];
#ifdef CONFIG_DEBUG_BLK_CGROUP
	/* Time not charged to this cgroup */
	uint64_t unaccounted_time;

	/* Sum of number of IOs queued across all samples */
	uint64_t avg_queue_size_sum;
	/* Count of samples taken for average */
	uint64_t avg_queue_size_samples;
	/* How many times this group has been removed from service tree */
	unsigned long dequeue;

	/* Total time spent waiting for it to be assigned a timeslice. */
	uint64_t group_wait_time;
	uint64_t start_group_wait_time;

	/* Time spent idling for this blkio_group */
	uint64_t idle_time;
	uint64_t start_idle_time;
	/*
	 * Total time when we have requests queued and do not contain the
	 * current active queue.
	 */
	uint64_t empty_time;
	uint64_t start_empty_time;
	uint16_t flags;
#endif
};

/* Per cpu blkio group stats */
struct blkio_group_stats_cpu {
	uint64_t sectors;
	uint64_t stat_arr_cpu[BLKIO_STAT_CPU_NR][BLKIO_STAT_TOTAL];
	struct u64_stats_sync syncp;
};

struct blkio_group {
	/* An rcu protected unique identifier for the group */
	void *key;
	struct hlist_node blkcg_node;
	unsigned short blkcg_id;
	/* Store cgroup path */
	char path[128];
	/* The device MKDEV(major, minor), this group has been created for */
	dev_t dev;
	/* policy which owns this blk group */
	enum blkio_policy_id plid;

	/* Need to serialize the stats in the case of reset/update */
	spinlock_t stats_lock;
	struct blkio_group_stats stats;
	/* Per cpu stats pointer */
	struct blkio_group_stats_cpu __percpu *stats_cpu;
};

struct blkio_policy_node {
	struct list_head node;
	dev_t dev;
	/* This node belongs to max bw policy or porportional weight policy */
	enum blkio_policy_id plid;
	/* cgroup file to which this rule belongs to */
	int fileid;

	union {
		unsigned int weight;
		/*
		 * Rate read/write in terms of bytes per second
		 * Whether this rate represents read or write is determined
		 * by file type "fileid".
		 */
		u64 bps;
		unsigned int iops;
	} val;
};

extern unsigned int blkcg_get_weight(struct blkio_cgroup *blkcg,
				     dev_t dev);
extern uint64_t blkcg_get_read_bps(struct blkio_cgroup *blkcg,
				     dev_t dev);
extern uint64_t blkcg_get_write_bps(struct blkio_cgroup *blkcg,
				     dev_t dev);
extern unsigned int blkcg_get_read_iops(struct blkio_cgroup *blkcg,
				     dev_t dev);
extern unsigned int blkcg_get_write_iops(struct blkio_cgroup *blkcg,
				     dev_t dev);

typedef void (blkio_unlink_group_fn) (void *key, struct blkio_group *blkg);

typedef void (blkio_update_group_weight_fn) (void *key,
			struct blkio_group *blkg, unsigned int weight);
typedef void (blkio_update_group_read_bps_fn) (void * key,
			struct blkio_group *blkg, u64 read_bps);
typedef void (blkio_update_group_write_bps_fn) (void *key,
			struct blkio_group *blkg, u64 write_bps);
typedef void (blkio_update_group_read_iops_fn) (void *key,
			struct blkio_group *blkg, unsigned int read_iops);
typedef void (blkio_update_group_write_iops_fn) (void *key,
			struct blkio_group *blkg, unsigned int write_iops);

struct blkio_policy_ops {
	blkio_unlink_group_fn *blkio_unlink_group_fn;
	blkio_update_group_weight_fn *blkio_update_group_weight_fn;
	blkio_update_group_read_bps_fn *blkio_update_group_read_bps_fn;
	blkio_update_group_write_bps_fn *blkio_update_group_write_bps_fn;
	blkio_update_group_read_iops_fn *blkio_update_group_read_iops_fn;
	blkio_update_group_write_iops_fn *blkio_update_group_write_iops_fn;
};

struct blkio_policy_type {
	struct list_head list;
	struct blkio_policy_ops ops;
	enum blkio_policy_id plid;
};

/* Blkio controller policy registration */
extern void blkio_policy_register(struct blkio_policy_type *);
extern void blkio_policy_unregister(struct blkio_policy_type *);

static inline char *blkg_path(struct blkio_group *blkg)
{
	return blkg->path;
}

#else

struct blkio_group {
};

struct blkio_policy_type {
};

static inline void blkio_policy_register(struct blkio_policy_type *blkiop) { }
static inline void blkio_policy_unregister(struct blkio_policy_type *blkiop) { }

static inline char *blkg_path(struct blkio_group *blkg) { return NULL; }

#endif

#define BLKIO_WEIGHT_MIN	10
#define BLKIO_WEIGHT_MAX	1000
#define BLKIO_WEIGHT_DEFAULT	500

#ifdef CONFIG_DEBUG_BLK_CGROUP
void blkiocg_update_avg_queue_size_stats(struct blkio_group *blkg);
void blkiocg_update_dequeue_stats(struct blkio_group *blkg,
				unsigned long dequeue);
void blkiocg_update_set_idle_time_stats(struct blkio_group *blkg);
void blkiocg_update_idle_time_stats(struct blkio_group *blkg);
void blkiocg_set_start_empty_time(struct blkio_group *blkg);

#define BLKG_FLAG_FNS(name)						\
static inline void blkio_mark_blkg_##name(				\
		struct blkio_group_stats *stats)			\
{									\
	stats->flags |= (1 << BLKG_##name);				\
}									\
static inline void blkio_clear_blkg_##name(				\
		struct blkio_group_stats *stats)			\
{									\
	stats->flags &= ~(1 << BLKG_##name);				\
}									\
static inline int blkio_blkg_##name(struct blkio_group_stats *stats)	\
{									\
	return (stats->flags & (1 << BLKG_##name)) != 0;		\
}									\

BLKG_FLAG_FNS(waiting)
BLKG_FLAG_FNS(idling)
BLKG_FLAG_FNS(empty)
#undef BLKG_FLAG_FNS
#else
static inline void blkiocg_update_avg_queue_size_stats(
						struct blkio_group *blkg) {}
static inline void blkiocg_update_dequeue_stats(struct blkio_group *blkg,
						unsigned long dequeue) {}
static inline void blkiocg_update_set_idle_time_stats(struct blkio_group *blkg)
{}
static inline void blkiocg_update_idle_time_stats(struct blkio_group *blkg) {}
static inline void blkiocg_set_start_empty_time(struct blkio_group *blkg) {}
#endif

#if defined(CONFIG_BLK_CGROUP) || defined(CONFIG_BLK_CGROUP_MODULE)
extern struct blkio_cgroup blkio_root_cgroup;
extern struct blkio_cgroup *cgroup_to_blkio_cgroup(struct cgroup *cgroup);
extern struct blkio_cgroup *task_blkio_cgroup(struct task_struct *tsk);
extern void blkiocg_add_blkio_group(struct blkio_cgroup *blkcg,
	struct blkio_group *blkg, void *key, dev_t dev,
	enum blkio_policy_id plid);
extern int blkio_alloc_blkg_stats(struct blkio_group *blkg);
extern int blkiocg_del_blkio_group(struct blkio_group *blkg);
extern struct blkio_group *blkiocg_lookup_group(struct blkio_cgroup *blkcg,
						void *key);
void blkiocg_update_timeslice_used(struct blkio_group *blkg,
					unsigned long time,
					unsigned long unaccounted_time);
void blkiocg_update_dispatch_stats(struct blkio_group *blkg, uint64_t bytes,
						bool direction, bool sync);
void blkiocg_update_completion_stats(struct blkio_group *blkg,
	uint64_t start_time, uint64_t io_start_time, bool direction, bool sync);
void blkiocg_update_io_merged_stats(struct blkio_group *blkg, bool direction,
					bool sync);
void blkiocg_update_io_add_stats(struct blkio_group *blkg,
		struct blkio_group *curr_blkg, bool direction, bool sync);
void blkiocg_update_io_remove_stats(struct blkio_group *blkg,
					bool direction, bool sync);
#else
struct cgroup;
static inline struct blkio_cgroup *
cgroup_to_blkio_cgroup(struct cgroup *cgroup) { return NULL; }
static inline struct blkio_cgroup *
task_blkio_cgroup(struct task_struct *tsk) { return NULL; }

static inline void blkiocg_add_blkio_group(struct blkio_cgroup *blkcg,
		struct blkio_group *blkg, void *key, dev_t dev,
		enum blkio_policy_id plid) {}

static inline int blkio_alloc_blkg_stats(struct blkio_group *blkg) { return 0; }

static inline int
blkiocg_del_blkio_group(struct blkio_group *blkg) { return 0; }

static inline struct blkio_group *
blkiocg_lookup_group(struct blkio_cgroup *blkcg, void *key) { return NULL; }
static inline void blkiocg_update_timeslice_used(struct blkio_group *blkg,
						unsigned long time,
						unsigned long unaccounted_time)
{}
static inline void blkiocg_update_dispatch_stats(struct blkio_group *blkg,
				uint64_t bytes, bool direction, bool sync) {}
static inline void blkiocg_update_completion_stats(struct blkio_group *blkg,
		uint64_t start_time, uint64_t io_start_time, bool direction,
		bool sync) {}
static inline void blkiocg_update_io_merged_stats(struct blkio_group *blkg,
						bool direction, bool sync) {}
static inline void blkiocg_update_io_add_stats(struct blkio_group *blkg,
		struct blkio_group *curr_blkg, bool direction, bool sync) {}
static inline void blkiocg_update_io_remove_stats(struct blkio_group *blkg,
						bool direction, bool sync) {}
#endif
#endif /* _BLK_CGROUP_H */
Commit	Line	Data
	1	#ifndef _BLK_CGROUP_H
	2	#define _BLK_CGROUP_H
	3	/*
	4	* Common Block IO controller cgroup interface
	5	*
	6	* Based on ideas and code from CFQ, CFS and BFQ:
	7	* Copyright (C) 2003 Jens Axboe <axboe@kernel.dk>
	8	*
	9	* Copyright (C) 2008 Fabio Checconi <fabio@gandalf.sssup.it>
	10	* Paolo Valente <paolo.valente@unimore.it>
	11	*
	12	* Copyright (C) 2009 Vivek Goyal <vgoyal@redhat.com>
	13	* Nauman Rafique <nauman@google.com>
	14	*/
	15
	16	#include <linux/cgroup.h>
	17	#include <linux/u64_stats_sync.h>
	18
	19	enum blkio_policy_id {
	20	BLKIO_POLICY_PROP = 0, /* Proportional Bandwidth division */
	21	BLKIO_POLICY_THROTL, /* Throttling */
	22	};
	23
	24	/* Max limits for throttle policy */
	25	#define THROTL_IOPS_MAX UINT_MAX
	26
	27	#if defined(CONFIG_BLK_CGROUP) \|\| defined(CONFIG_BLK_CGROUP_MODULE)
	28
	29	#ifndef CONFIG_BLK_CGROUP
	30	/* When blk-cgroup is a module, its subsys_id isn't a compile-time constant */
	31	extern struct cgroup_subsys blkio_subsys;
	32	#define blkio_subsys_id blkio_subsys.subsys_id
	33	#endif
	34
	35	enum stat_type {
	36	/* Total time spent (in ns) between request dispatch to the driver and
	37	* request completion for IOs doen by this cgroup. This may not be
	38	* accurate when NCQ is turned on. */
	39	BLKIO_STAT_SERVICE_TIME = 0,
	40	/* Total time spent waiting in scheduler queue in ns */
	41	BLKIO_STAT_WAIT_TIME,
	42	/* Number of IOs queued up */
	43	BLKIO_STAT_QUEUED,
	44	/* All the single valued stats go below this */
	45	BLKIO_STAT_TIME,
	46	#ifdef CONFIG_DEBUG_BLK_CGROUP
	47	/* Time not charged to this cgroup */
	48	BLKIO_STAT_UNACCOUNTED_TIME,
	49	BLKIO_STAT_AVG_QUEUE_SIZE,
	50	BLKIO_STAT_IDLE_TIME,
	51	BLKIO_STAT_EMPTY_TIME,
	52	BLKIO_STAT_GROUP_WAIT_TIME,
	53	BLKIO_STAT_DEQUEUE
	54	#endif
	55	};
	56
	57	/* Per cpu stats */
	58	enum stat_type_cpu {
	59	BLKIO_STAT_CPU_SECTORS,
	60	/* Total bytes transferred */
	61	BLKIO_STAT_CPU_SERVICE_BYTES,
	62	/* Total IOs serviced, post merge */
	63	BLKIO_STAT_CPU_SERVICED,
	64	/* Number of IOs merged */
	65	BLKIO_STAT_CPU_MERGED,
	66	BLKIO_STAT_CPU_NR
	67	};
	68
	69	enum stat_sub_type {
	70	BLKIO_STAT_READ = 0,
	71	BLKIO_STAT_WRITE,
	72	BLKIO_STAT_SYNC,
	73	BLKIO_STAT_ASYNC,
	74	BLKIO_STAT_TOTAL
	75	};
	76
	77	/* blkg state flags */
	78	enum blkg_state_flags {
	79	BLKG_waiting = 0,
	80	BLKG_idling,
	81	BLKG_empty,
	82	};
	83
	84	/* cgroup files owned by proportional weight policy */
	85	enum blkcg_file_name_prop {
	86	BLKIO_PROP_weight = 1,
	87	BLKIO_PROP_weight_device,
	88	BLKIO_PROP_io_service_bytes,
	89	BLKIO_PROP_io_serviced,
	90	BLKIO_PROP_time,
	91	BLKIO_PROP_sectors,
	92	BLKIO_PROP_unaccounted_time,
	93	BLKIO_PROP_io_service_time,
	94	BLKIO_PROP_io_wait_time,
	95	BLKIO_PROP_io_merged,
	96	BLKIO_PROP_io_queued,
	97	BLKIO_PROP_avg_queue_size,
	98	BLKIO_PROP_group_wait_time,
	99	BLKIO_PROP_idle_time,
	100	BLKIO_PROP_empty_time,
	101	BLKIO_PROP_dequeue,
	102	};
	103
	104	/* cgroup files owned by throttle policy */
	105	enum blkcg_file_name_throtl {
	106	BLKIO_THROTL_read_bps_device,
	107	BLKIO_THROTL_write_bps_device,
	108	BLKIO_THROTL_read_iops_device,
	109	BLKIO_THROTL_write_iops_device,
	110	BLKIO_THROTL_io_service_bytes,
	111	BLKIO_THROTL_io_serviced,
	112	};
	113
	114	struct blkio_cgroup {
	115	struct cgroup_subsys_state css;
	116	unsigned int weight;
	117	spinlock_t lock;
	118	struct hlist_head blkg_list;
	119	struct list_head policy_list; /* list of blkio_policy_node */
	120	};
	121
	122	struct blkio_group_stats {
	123	/* total disk time and nr sectors dispatched by this group */
	124	uint64_t time;
	125	uint64_t stat_arr[BLKIO_STAT_QUEUED + 1][BLKIO_STAT_TOTAL];
	126	#ifdef CONFIG_DEBUG_BLK_CGROUP
	127	/* Time not charged to this cgroup */
	128	uint64_t unaccounted_time;
	129
	130	/* Sum of number of IOs queued across all samples */
	131	uint64_t avg_queue_size_sum;
	132	/* Count of samples taken for average */
	133	uint64_t avg_queue_size_samples;
	134	/* How many times this group has been removed from service tree */
	135	unsigned long dequeue;
	136
	137	/* Total time spent waiting for it to be assigned a timeslice. */
	138	uint64_t group_wait_time;
	139	uint64_t start_group_wait_time;
	140
	141	/* Time spent idling for this blkio_group */
	142	uint64_t idle_time;
	143	uint64_t start_idle_time;
	144	/*
	145	* Total time when we have requests queued and do not contain the
	146	* current active queue.
	147	*/
	148	uint64_t empty_time;
	149	uint64_t start_empty_time;
	150	uint16_t flags;
	151	#endif
	152	};
	153
	154	/* Per cpu blkio group stats */
	155	struct blkio_group_stats_cpu {
	156	uint64_t sectors;
	157	uint64_t stat_arr_cpu[BLKIO_STAT_CPU_NR][BLKIO_STAT_TOTAL];
	158	struct u64_stats_sync syncp;
	159	};
	160
	161	struct blkio_group {
	162	/* An rcu protected unique identifier for the group */
	163	void *key;
	164	struct hlist_node blkcg_node;
	165	unsigned short blkcg_id;
	166	/* Store cgroup path */
	167	char path[128];
	168	/* The device MKDEV(major, minor), this group has been created for */
	169	dev_t dev;
	170	/* policy which owns this blk group */
	171	enum blkio_policy_id plid;
	172
	173	/* Need to serialize the stats in the case of reset/update */
	174	spinlock_t stats_lock;
	175	struct blkio_group_stats stats;
	176	/* Per cpu stats pointer */
	177	struct blkio_group_stats_cpu __percpu *stats_cpu;
	178	};
	179
	180	struct blkio_policy_node {
	181	struct list_head node;
	182	dev_t dev;
	183	/* This node belongs to max bw policy or porportional weight policy */
	184	enum blkio_policy_id plid;
	185	/* cgroup file to which this rule belongs to */
	186	int fileid;
	187
	188	union {
	189	unsigned int weight;
	190	/*
	191	* Rate read/write in terms of bytes per second
	192	* Whether this rate represents read or write is determined
	193	* by file type "fileid".
	194	*/
	195	u64 bps;
	196	unsigned int iops;
	197	} val;
	198	};
	199
	200	extern unsigned int blkcg_get_weight(struct blkio_cgroup *blkcg,
	201	dev_t dev);
	202	extern uint64_t blkcg_get_read_bps(struct blkio_cgroup *blkcg,
	203	dev_t dev);
	204	extern uint64_t blkcg_get_write_bps(struct blkio_cgroup *blkcg,
	205	dev_t dev);
	206	extern unsigned int blkcg_get_read_iops(struct blkio_cgroup *blkcg,
	207	dev_t dev);
	208	extern unsigned int blkcg_get_write_iops(struct blkio_cgroup *blkcg,
	209	dev_t dev);
	210
	211	typedef void (blkio_unlink_group_fn) (void key, struct blkio_group blkg);
	212
	213	typedef void (blkio_update_group_weight_fn) (void *key,
	214	struct blkio_group *blkg, unsigned int weight);
	215	typedef void (blkio_update_group_read_bps_fn) (void * key,
	216	struct blkio_group *blkg, u64 read_bps);
	217	typedef void (blkio_update_group_write_bps_fn) (void *key,
	218	struct blkio_group *blkg, u64 write_bps);
	219	typedef void (blkio_update_group_read_iops_fn) (void *key,
	220	struct blkio_group *blkg, unsigned int read_iops);
	221	typedef void (blkio_update_group_write_iops_fn) (void *key,
	222	struct blkio_group *blkg, unsigned int write_iops);
	223
	224	struct blkio_policy_ops {
	225	blkio_unlink_group_fn *blkio_unlink_group_fn;
	226	blkio_update_group_weight_fn *blkio_update_group_weight_fn;
	227	blkio_update_group_read_bps_fn *blkio_update_group_read_bps_fn;
	228	blkio_update_group_write_bps_fn *blkio_update_group_write_bps_fn;
	229	blkio_update_group_read_iops_fn *blkio_update_group_read_iops_fn;
	230	blkio_update_group_write_iops_fn *blkio_update_group_write_iops_fn;
	231	};
	232
	233	struct blkio_policy_type {
	234	struct list_head list;
	235	struct blkio_policy_ops ops;
	236	enum blkio_policy_id plid;
	237	};
	238
	239	/* Blkio controller policy registration */
	240	extern void blkio_policy_register(struct blkio_policy_type *);
	241	extern void blkio_policy_unregister(struct blkio_policy_type *);
	242
	243	static inline char blkg_path(struct blkio_group blkg)
	244	{
	245	return blkg->path;
	246	}
	247
	248	#else
	249
	250	struct blkio_group {
	251	};
	252
	253	struct blkio_policy_type {
	254	};
	255
	256	static inline void blkio_policy_register(struct blkio_policy_type *blkiop) { }
	257	static inline void blkio_policy_unregister(struct blkio_policy_type *blkiop) { }
	258
	259	static inline char blkg_path(struct blkio_group blkg) { return NULL; }
	260
	261	#endif
	262
	263	#define BLKIO_WEIGHT_MIN 10
	264	#define BLKIO_WEIGHT_MAX 1000
	265	#define BLKIO_WEIGHT_DEFAULT 500
	266
	267	#ifdef CONFIG_DEBUG_BLK_CGROUP
	268	void blkiocg_update_avg_queue_size_stats(struct blkio_group *blkg);
	269	void blkiocg_update_dequeue_stats(struct blkio_group *blkg,
	270	unsigned long dequeue);
	271	void blkiocg_update_set_idle_time_stats(struct blkio_group *blkg);
	272	void blkiocg_update_idle_time_stats(struct blkio_group *blkg);
	273	void blkiocg_set_start_empty_time(struct blkio_group *blkg);
	274
	275	#define BLKG_FLAG_FNS(name) \
	276	static inline void blkio_mark_blkg_##name( \
	277	struct blkio_group_stats *stats) \
	278	{ \
	279	stats->flags \|= (1 << BLKG_##name); \
	280	} \
	281	static inline void blkio_clear_blkg_##name( \
	282	struct blkio_group_stats *stats) \
	283	{ \
	284	stats->flags &= ~(1 << BLKG_##name); \
	285	} \
	286	static inline int blkio_blkg_##name(struct blkio_group_stats *stats) \
	287	{ \
	288	return (stats->flags & (1 << BLKG_##name)) != 0; \
	289	} \
	290
	291	BLKG_FLAG_FNS(waiting)
	292	BLKG_FLAG_FNS(idling)
	293	BLKG_FLAG_FNS(empty)
	294	#undef BLKG_FLAG_FNS
	295	#else
	296	static inline void blkiocg_update_avg_queue_size_stats(
	297	struct blkio_group *blkg) {}
	298	static inline void blkiocg_update_dequeue_stats(struct blkio_group *blkg,
	299	unsigned long dequeue) {}
	300	static inline void blkiocg_update_set_idle_time_stats(struct blkio_group *blkg)
	301	{}
	302	static inline void blkiocg_update_idle_time_stats(struct blkio_group *blkg) {}
	303	static inline void blkiocg_set_start_empty_time(struct blkio_group *blkg) {}
	304	#endif
	305
	306	#if defined(CONFIG_BLK_CGROUP) \|\| defined(CONFIG_BLK_CGROUP_MODULE)
	307	extern struct blkio_cgroup blkio_root_cgroup;
	308	extern struct blkio_cgroup cgroup_to_blkio_cgroup(struct cgroup cgroup);
	309	extern struct blkio_cgroup task_blkio_cgroup(struct task_struct tsk);
	310	extern void blkiocg_add_blkio_group(struct blkio_cgroup *blkcg,
	311	struct blkio_group blkg, void key, dev_t dev,
	312	enum blkio_policy_id plid);
	313	extern int blkio_alloc_blkg_stats(struct blkio_group *blkg);
	314	extern int blkiocg_del_blkio_group(struct blkio_group *blkg);
	315	extern struct blkio_group blkiocg_lookup_group(struct blkio_cgroup blkcg,
	316	void *key);
	317	void blkiocg_update_timeslice_used(struct blkio_group *blkg,
	318	unsigned long time,
	319	unsigned long unaccounted_time);
	320	void blkiocg_update_dispatch_stats(struct blkio_group *blkg, uint64_t bytes,
	321	bool direction, bool sync);
	322	void blkiocg_update_completion_stats(struct blkio_group *blkg,
	323	uint64_t start_time, uint64_t io_start_time, bool direction, bool sync);
	324	void blkiocg_update_io_merged_stats(struct blkio_group *blkg, bool direction,
	325	bool sync);
	326	void blkiocg_update_io_add_stats(struct blkio_group *blkg,
	327	struct blkio_group *curr_blkg, bool direction, bool sync);
	328	void blkiocg_update_io_remove_stats(struct blkio_group *blkg,
	329	bool direction, bool sync);
	330	#else
	331	struct cgroup;
	332	static inline struct blkio_cgroup *
	333	cgroup_to_blkio_cgroup(struct cgroup *cgroup) { return NULL; }
	334	static inline struct blkio_cgroup *
	335	task_blkio_cgroup(struct task_struct *tsk) { return NULL; }
	336
	337	static inline void blkiocg_add_blkio_group(struct blkio_cgroup *blkcg,
	338	struct blkio_group blkg, void key, dev_t dev,
	339	enum blkio_policy_id plid) {}
	340
	341	static inline int blkio_alloc_blkg_stats(struct blkio_group *blkg) { return 0; }
	342
	343	static inline int
	344	blkiocg_del_blkio_group(struct blkio_group *blkg) { return 0; }
	345
	346	static inline struct blkio_group *
	347	blkiocg_lookup_group(struct blkio_cgroup blkcg, void key) { return NULL; }
	348	static inline void blkiocg_update_timeslice_used(struct blkio_group *blkg,
	349	unsigned long time,
	350	unsigned long unaccounted_time)
	351	{}
	352	static inline void blkiocg_update_dispatch_stats(struct blkio_group *blkg,
	353	uint64_t bytes, bool direction, bool sync) {}
	354	static inline void blkiocg_update_completion_stats(struct blkio_group *blkg,
	355	uint64_t start_time, uint64_t io_start_time, bool direction,
	356	bool sync) {}
	357	static inline void blkiocg_update_io_merged_stats(struct blkio_group *blkg,
	358	bool direction, bool sync) {}
	359	static inline void blkiocg_update_io_add_stats(struct blkio_group *blkg,
	360	struct blkio_group *curr_blkg, bool direction, bool sync) {}
	361	static inline void blkiocg_update_io_remove_stats(struct blkio_group *blkg,
	362	bool direction, bool sync) {}
	363	#endif
	364	#endif /* _BLK_CGROUP_H */