[mirror_ubuntu-artful-kernel.git] / include / linux / iocontext.h

#ifndef IOCONTEXT_H
#define IOCONTEXT_H

/*
 * This is the per-process anticipatory I/O scheduler state.
 */
struct as_io_context {
	spinlock_t lock;

	void (*dtor)(struct as_io_context *aic); /* destructor */
	void (*exit)(struct as_io_context *aic); /* called on task exit */

	unsigned long state;
	atomic_t nr_queued; /* queued reads & sync writes */
	atomic_t nr_dispatched; /* number of requests gone to the drivers */

	/* IO History tracking */
	/* Thinktime */
	unsigned long last_end_request;
	unsigned long ttime_total;
	unsigned long ttime_samples;
	unsigned long ttime_mean;
	/* Layout pattern */
	unsigned int seek_samples;
	sector_t last_request_pos;
	u64 seek_total;
	sector_t seek_mean;
};

struct cfq_queue;
struct cfq_io_context {
	struct rb_node rb_node;
	void *key;

	struct cfq_queue *cfqq[2];

	struct io_context *ioc;

	unsigned long last_end_request;
	sector_t last_request_pos;

	unsigned long ttime_total;
	unsigned long ttime_samples;
	unsigned long ttime_mean;

	unsigned int seek_samples;
	u64 seek_total;
	sector_t seek_mean;

	struct list_head queue_list;

	void (*dtor)(struct io_context *); /* destructor */
	void (*exit)(struct io_context *); /* called on task exit */
};

/*
 * I/O subsystem state of the associated processes.  It is refcounted
 * and kmalloc'ed. These could be shared between processes.
 */
struct io_context {
	atomic_t refcount;
	atomic_t nr_tasks;

	/* all the fields below are protected by this lock */
	spinlock_t lock;

	unsigned short ioprio;
	unsigned short ioprio_changed;

	/*
	 * For request batching
	 */
	unsigned long last_waited; /* Time last woken after wait for request */
	int nr_batch_requests;     /* Number of requests left in the batch */

	struct as_io_context *aic;
	struct rb_root cic_root;
	void *ioc_data;
};

static inline struct io_context *ioc_task_link(struct io_context *ioc)
{
	/*
	 * if ref count is zero, don't allow sharing (ioc is going away, it's
	 * a race).
	 */
	if (ioc && atomic_inc_not_zero(&ioc->refcount))
		return ioc;

	return NULL;
}

#endif
Commit	Line	Data
fd0928df JA	1	#ifndef IOCONTEXT_H
	2	#define IOCONTEXT_H
	3
	4	/*
	5	* This is the per-process anticipatory I/O scheduler state.
	6	*/
	7	struct as_io_context {
	8	spinlock_t lock;
	9
	10	void (dtor)(struct as_io_context aic); /* destructor */
	11	void (exit)(struct as_io_context aic); /* called on task exit */
	12
	13	unsigned long state;
	14	atomic_t nr_queued; /* queued reads & sync writes */
	15	atomic_t nr_dispatched; /* number of requests gone to the drivers */
	16
	17	/* IO History tracking */
	18	/* Thinktime */
	19	unsigned long last_end_request;
	20	unsigned long ttime_total;
	21	unsigned long ttime_samples;
	22	unsigned long ttime_mean;
	23	/* Layout pattern */
	24	unsigned int seek_samples;
	25	sector_t last_request_pos;
	26	u64 seek_total;
	27	sector_t seek_mean;
	28	};
	29
	30	struct cfq_queue;
	31	struct cfq_io_context {
	32	struct rb_node rb_node;
	33	void *key;
	34
	35	struct cfq_queue *cfqq[2];
	36
	37	struct io_context *ioc;
	38
	39	unsigned long last_end_request;
	40	sector_t last_request_pos;
	41
	42	unsigned long ttime_total;
	43	unsigned long ttime_samples;
	44	unsigned long ttime_mean;
	45
	46	unsigned int seek_samples;
	47	u64 seek_total;
	48	sector_t seek_mean;
	49
	50	struct list_head queue_list;
	51
	52	void (dtor)(struct io_context ); /* destructor */
	53	void (exit)(struct io_context ); /* called on task exit */
	54	};
	55
	56	/*
d38ecf93 JA	57	* I/O subsystem state of the associated processes. It is refcounted
d38ecf93 JA	58	* and kmalloc'ed. These could be shared between processes.
fd0928df JA	59	*/
	60	struct io_context {
	61	atomic_t refcount;
d38ecf93 JA	62	atomic_t nr_tasks;
	63
	64	/* all the fields below are protected by this lock */
	65	spinlock_t lock;
fd0928df JA	66
	67	unsigned short ioprio;
	68	unsigned short ioprio_changed;
	69
	70	/*
	71	* For request batching
	72	*/
	73	unsigned long last_waited; /* Time last woken after wait for request */
	74	int nr_batch_requests; /* Number of requests left in the batch */
	75
	76	struct as_io_context *aic;
	77	struct rb_root cic_root;
	78	void *ioc_data;
	79	};
	80
d38ecf93 JA	81	static inline struct io_context ioc_task_link(struct io_context ioc)
	82	{
	83	/*
	84	* if ref count is zero, don't allow sharing (ioc is going away, it's
	85	* a race).
	86	*/
	87	if (ioc && atomic_inc_not_zero(&ioc->refcount))
	88	return ioc;
	89
	90	return NULL;
	91	}
	92
fd0928df	93	#endif