block/blk-cgroup.h - kernel/msm-4.9 - Gitiles

 #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>

 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 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,
 };

 /* 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_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 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;
 	/* 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;
 };

 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 byptes 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 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 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,
 		enum blkio_policy_id plid) {}

 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 */
	#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>

	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 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,
	};

	/* 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_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 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;
	/* 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;
	};

	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 byptes 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 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 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,
	enum blkio_policy_id plid) {}

	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 */