[net-next-2.6.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>

#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 bytes transferred */
	BLKIO_STAT_SERVICE_BYTES,
	/* Total IOs serviced, post merge */
	BLKIO_STAT_SERVICED,
	/* Total time spent waiting in scheduler queue in ns */
	BLKIO_STAT_WAIT_TIME,
	/* Number of IOs merged */
	BLKIO_STAT_MERGED,
	/* Number of IOs queued up */
	BLKIO_STAT_QUEUED,
	/* All the single valued stats go below this */
	BLKIO_STAT_TIME,
	BLKIO_STAT_SECTORS,
#ifdef CONFIG_DEBUG_BLK_CGROUP
	BLKIO_STAT_AVG_QUEUE_SIZE,
	BLKIO_STAT_IDLE_TIME,
	BLKIO_STAT_EMPTY_TIME,
	BLKIO_STAT_GROUP_WAIT_TIME,
	BLKIO_STAT_DEQUEUE
#endif
};

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,
};

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 sectors;
	uint64_t stat_arr[BLKIO_STAT_QUEUED + 1][BLKIO_STAT_TOTAL];
#ifdef CONFIG_DEBUG_BLK_CGROUP
	/* 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
};

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;

	/* Need to serialize the stats in the case of reset/update */
	spinlock_t stats_lock;
	struct blkio_group_stats stats;
};

struct blkio_policy_node {
	struct list_head node;
	dev_t dev;
	unsigned int weight;
};

extern unsigned int blkcg_get_weight(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) (struct blkio_group *blkg,
						unsigned int weight);

struct blkio_policy_ops {
	blkio_unlink_group_fn *blkio_unlink_group_fn;
	blkio_update_group_weight_fn *blkio_update_group_weight_fn;
};

struct blkio_policy_type {
	struct list_head list;
	struct blkio_policy_ops ops;
};

/* 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	100
#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 void blkiocg_add_blkio_group(struct blkio_cgroup *blkcg,
			struct blkio_group *blkg, void *key, dev_t dev);
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);
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 void blkiocg_add_blkio_group(struct blkio_cgroup *blkcg,
			struct blkio_group *blkg, void *key, dev_t dev) {}

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) {}
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
31e4c28d VG	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
67523c48 BB	18	#if defined(CONFIG_BLK_CGROUP) \|\| defined(CONFIG_BLK_CGROUP_MODULE)
	19
	20	#ifndef CONFIG_BLK_CGROUP
	21	/* When blk-cgroup is a module, its subsys_id isn't a compile-time constant */
	22	extern struct cgroup_subsys blkio_subsys;
	23	#define blkio_subsys_id blkio_subsys.subsys_id
	24	#endif
2f5ea477	25
84c124da DS	26	enum stat_type {
	27	/* Total time spent (in ns) between request dispatch to the driver and
	28	* request completion for IOs doen by this cgroup. This may not be
	29	* accurate when NCQ is turned on. */
	30	BLKIO_STAT_SERVICE_TIME = 0,
	31	/* Total bytes transferred */
	32	BLKIO_STAT_SERVICE_BYTES,
	33	/* Total IOs serviced, post merge */
	34	BLKIO_STAT_SERVICED,
	35	/* Total time spent waiting in scheduler queue in ns */
	36	BLKIO_STAT_WAIT_TIME,
812d4026 DS	37	/* Number of IOs merged */
812d4026 DS	38	BLKIO_STAT_MERGED,
cdc1184c DS	39	/* Number of IOs queued up */
cdc1184c DS	40	BLKIO_STAT_QUEUED,
84c124da DS	41	/* All the single valued stats go below this */
	42	BLKIO_STAT_TIME,
	43	BLKIO_STAT_SECTORS,
	44	#ifdef CONFIG_DEBUG_BLK_CGROUP
cdc1184c	45	BLKIO_STAT_AVG_QUEUE_SIZE,
812df48d DS	46	BLKIO_STAT_IDLE_TIME,
	47	BLKIO_STAT_EMPTY_TIME,
	48	BLKIO_STAT_GROUP_WAIT_TIME,
84c124da DS	49	BLKIO_STAT_DEQUEUE
	50	#endif
	51	};
	52
	53	enum stat_sub_type {
	54	BLKIO_STAT_READ = 0,
	55	BLKIO_STAT_WRITE,
	56	BLKIO_STAT_SYNC,
	57	BLKIO_STAT_ASYNC,
	58	BLKIO_STAT_TOTAL
303a3acb DS	59	};
303a3acb DS	60
812df48d DS	61	/* blkg state flags */
	62	enum blkg_state_flags {
	63	BLKG_waiting = 0,
	64	BLKG_idling,
	65	BLKG_empty,
	66	};
	67
31e4c28d VG	68	struct blkio_cgroup {
	69	struct cgroup_subsys_state css;
	70	unsigned int weight;
	71	spinlock_t lock;
	72	struct hlist_head blkg_list;
34d0f179	73	struct list_head policy_list; /* list of blkio_policy_node */
31e4c28d VG	74	};
31e4c28d VG	75
303a3acb DS	76	struct blkio_group_stats {
	77	/* total disk time and nr sectors dispatched by this group */
	78	uint64_t time;
	79	uint64_t sectors;
cdc1184c	80	uint64_t stat_arr[BLKIO_STAT_QUEUED + 1][BLKIO_STAT_TOTAL];
303a3acb	81	#ifdef CONFIG_DEBUG_BLK_CGROUP
cdc1184c DS	82	/* Sum of number of IOs queued across all samples */
	83	uint64_t avg_queue_size_sum;
	84	/* Count of samples taken for average */
	85	uint64_t avg_queue_size_samples;
303a3acb DS	86	/* How many times this group has been removed from service tree */
303a3acb DS	87	unsigned long dequeue;
812df48d DS	88
	89	/* Total time spent waiting for it to be assigned a timeslice. */
	90	uint64_t group_wait_time;
	91	uint64_t start_group_wait_time;
	92
	93	/* Time spent idling for this blkio_group */
	94	uint64_t idle_time;
	95	uint64_t start_idle_time;
	96	/*
	97	* Total time when we have requests queued and do not contain the
	98	* current active queue.
	99	*/
	100	uint64_t empty_time;
	101	uint64_t start_empty_time;
	102	uint16_t flags;
303a3acb DS	103	#endif
	104	};
	105
31e4c28d VG	106	struct blkio_group {
	107	/* An rcu protected unique identifier for the group */
	108	void *key;
	109	struct hlist_node blkcg_node;
b1c35769	110	unsigned short blkcg_id;
2868ef7b VG	111	/* Store cgroup path */
2868ef7b VG	112	char path[128];
22084190	113	/* The device MKDEV(major, minor), this group has been created for */
84c124da	114	dev_t dev;
22084190	115
303a3acb DS	116	/* Need to serialize the stats in the case of reset/update */
	117	spinlock_t stats_lock;
	118	struct blkio_group_stats stats;
31e4c28d VG	119	};
31e4c28d VG	120
34d0f179 GJ	121	struct blkio_policy_node {
	122	struct list_head node;
	123	dev_t dev;
	124	unsigned int weight;
	125	};
	126
	127	extern unsigned int blkcg_get_weight(struct blkio_cgroup *blkcg,
	128	dev_t dev);
	129
3e252066 VG	130	typedef void (blkio_unlink_group_fn) (void key, struct blkio_group blkg);
	131	typedef void (blkio_update_group_weight_fn) (struct blkio_group *blkg,
	132	unsigned int weight);
	133
	134	struct blkio_policy_ops {
	135	blkio_unlink_group_fn *blkio_unlink_group_fn;
	136	blkio_update_group_weight_fn *blkio_update_group_weight_fn;
	137	};
	138
	139	struct blkio_policy_type {
	140	struct list_head list;
	141	struct blkio_policy_ops ops;
	142	};
	143
	144	/* Blkio controller policy registration */
	145	extern void blkio_policy_register(struct blkio_policy_type *);
	146	extern void blkio_policy_unregister(struct blkio_policy_type *);
	147
afc24d49 VG	148	static inline char blkg_path(struct blkio_group blkg)
	149	{
	150	return blkg->path;
	151	}
	152
2f5ea477 JA	153	#else
	154
	155	struct blkio_group {
	156	};
	157
3e252066 VG	158	struct blkio_policy_type {
	159	};
	160
	161	static inline void blkio_policy_register(struct blkio_policy_type *blkiop) { }
	162	static inline void blkio_policy_unregister(struct blkio_policy_type *blkiop) { }
	163
afc24d49 VG	164	static inline char blkg_path(struct blkio_group blkg) { return NULL; }
afc24d49 VG	165
2f5ea477 JA	166	#endif
2f5ea477 JA	167
31e4c28d VG	168	#define BLKIO_WEIGHT_MIN 100
	169	#define BLKIO_WEIGHT_MAX 1000
	170	#define BLKIO_WEIGHT_DEFAULT 500
	171
2868ef7b	172	#ifdef CONFIG_DEBUG_BLK_CGROUP
a11cdaa7	173	void blkiocg_update_avg_queue_size_stats(struct blkio_group *blkg);
9195291e	174	void blkiocg_update_dequeue_stats(struct blkio_group *blkg,
22084190	175	unsigned long dequeue);
812df48d DS	176	void blkiocg_update_set_idle_time_stats(struct blkio_group *blkg);
812df48d DS	177	void blkiocg_update_idle_time_stats(struct blkio_group *blkg);
e5ff082e	178	void blkiocg_set_start_empty_time(struct blkio_group *blkg);
812df48d DS	179
	180	#define BLKG_FLAG_FNS(name) \
	181	static inline void blkio_mark_blkg_##name( \
	182	struct blkio_group_stats *stats) \
	183	{ \
	184	stats->flags \|= (1 << BLKG_##name); \
	185	} \
	186	static inline void blkio_clear_blkg_##name( \
	187	struct blkio_group_stats *stats) \
	188	{ \
	189	stats->flags &= ~(1 << BLKG_##name); \
	190	} \
	191	static inline int blkio_blkg_##name(struct blkio_group_stats *stats) \
	192	{ \
	193	return (stats->flags & (1 << BLKG_##name)) != 0; \
	194	} \
	195
	196	BLKG_FLAG_FNS(waiting)
	197	BLKG_FLAG_FNS(idling)
	198	BLKG_FLAG_FNS(empty)
	199	#undef BLKG_FLAG_FNS
2868ef7b	200	#else
a11cdaa7	201	static inline void blkiocg_update_avg_queue_size_stats(
cdc1184c	202	struct blkio_group *blkg) {}
9195291e DS	203	static inline void blkiocg_update_dequeue_stats(struct blkio_group *blkg,
9195291e DS	204	unsigned long dequeue) {}
812df48d DS	205	static inline void blkiocg_update_set_idle_time_stats(struct blkio_group *blkg)
	206	{}
	207	static inline void blkiocg_update_idle_time_stats(struct blkio_group *blkg) {}
e5ff082e	208	static inline void blkiocg_set_start_empty_time(struct blkio_group *blkg) {}
2868ef7b VG	209	#endif
2868ef7b VG	210
67523c48	211	#if defined(CONFIG_BLK_CGROUP) \|\| defined(CONFIG_BLK_CGROUP_MODULE)
31e4c28d VG	212	extern struct blkio_cgroup blkio_root_cgroup;
	213	extern struct blkio_cgroup cgroup_to_blkio_cgroup(struct cgroup cgroup);
	214	extern void blkiocg_add_blkio_group(struct blkio_cgroup *blkcg,
22084190	215	struct blkio_group blkg, void key, dev_t dev);
31e4c28d VG	216	extern int blkiocg_del_blkio_group(struct blkio_group *blkg);
	217	extern struct blkio_group blkiocg_lookup_group(struct blkio_cgroup blkcg,
	218	void *key);
303a3acb DS	219	void blkiocg_update_timeslice_used(struct blkio_group *blkg,
303a3acb DS	220	unsigned long time);
84c124da DS	221	void blkiocg_update_dispatch_stats(struct blkio_group *blkg, uint64_t bytes,
	222	bool direction, bool sync);
	223	void blkiocg_update_completion_stats(struct blkio_group *blkg,
	224	uint64_t start_time, uint64_t io_start_time, bool direction, bool sync);
812d4026 DS	225	void blkiocg_update_io_merged_stats(struct blkio_group *blkg, bool direction,
812d4026 DS	226	bool sync);
a11cdaa7	227	void blkiocg_update_io_add_stats(struct blkio_group *blkg,
cdc1184c	228	struct blkio_group *curr_blkg, bool direction, bool sync);
a11cdaa7	229	void blkiocg_update_io_remove_stats(struct blkio_group *blkg,
cdc1184c	230	bool direction, bool sync);
31e4c28d	231	#else
2f5ea477	232	struct cgroup;
31e4c28d VG	233	static inline struct blkio_cgroup *
	234	cgroup_to_blkio_cgroup(struct cgroup *cgroup) { return NULL; }
	235
	236	static inline void blkiocg_add_blkio_group(struct blkio_cgroup *blkcg,
84c124da	237	struct blkio_group blkg, void key, dev_t dev) {}
31e4c28d VG	238
	239	static inline int
	240	blkiocg_del_blkio_group(struct blkio_group *blkg) { return 0; }
	241
	242	static inline struct blkio_group *
	243	blkiocg_lookup_group(struct blkio_cgroup blkcg, void key) { return NULL; }
303a3acb	244	static inline void blkiocg_update_timeslice_used(struct blkio_group *blkg,
9a0785b0	245	unsigned long time) {}
84c124da DS	246	static inline void blkiocg_update_dispatch_stats(struct blkio_group *blkg,
	247	uint64_t bytes, bool direction, bool sync) {}
	248	static inline void blkiocg_update_completion_stats(struct blkio_group *blkg,
	249	uint64_t start_time, uint64_t io_start_time, bool direction,
	250	bool sync) {}
812d4026 DS	251	static inline void blkiocg_update_io_merged_stats(struct blkio_group *blkg,
812d4026 DS	252	bool direction, bool sync) {}
a11cdaa7	253	static inline void blkiocg_update_io_add_stats(struct blkio_group *blkg,
cdc1184c	254	struct blkio_group *curr_blkg, bool direction, bool sync) {}
a11cdaa7	255	static inline void blkiocg_update_io_remove_stats(struct blkio_group *blkg,
cdc1184c	256	bool direction, bool sync) {}
31e4c28d VG	257	#endif
31e4c28d VG	258	#endif /* _BLK_CGROUP_H */