[deliverable/linux.git] / include / linux / iocontext.h

#ifndef IOCONTEXT_H
#define IOCONTEXT_H

#include <linux/radix-tree.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 {
	void *key;
	unsigned long dead_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 radix_tree_root radix_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
4ac845a2 JA	4	#include <linux/radix-tree.h>
4ac845a2 JA	5
fd0928df JA	6	/*
	7	* This is the per-process anticipatory I/O scheduler state.
	8	*/
	9	struct as_io_context {
	10	spinlock_t lock;
	11
	12	void (dtor)(struct as_io_context aic); /* destructor */
	13	void (exit)(struct as_io_context aic); /* called on task exit */
	14
	15	unsigned long state;
	16	atomic_t nr_queued; /* queued reads & sync writes */
	17	atomic_t nr_dispatched; /* number of requests gone to the drivers */
	18
	19	/* IO History tracking */
	20	/* Thinktime */
	21	unsigned long last_end_request;
	22	unsigned long ttime_total;
	23	unsigned long ttime_samples;
	24	unsigned long ttime_mean;
	25	/* Layout pattern */
	26	unsigned int seek_samples;
	27	sector_t last_request_pos;
	28	u64 seek_total;
	29	sector_t seek_mean;
	30	};
	31
	32	struct cfq_queue;
	33	struct cfq_io_context {
fd0928df	34	void *key;
4ac845a2	35	unsigned long dead_key;
fd0928df JA	36
	37	struct cfq_queue *cfqq[2];
	38
	39	struct io_context *ioc;
	40
	41	unsigned long last_end_request;
	42	sector_t last_request_pos;
	43
	44	unsigned long ttime_total;
	45	unsigned long ttime_samples;
	46	unsigned long ttime_mean;
	47
	48	unsigned int seek_samples;
	49	u64 seek_total;
	50	sector_t seek_mean;
	51
	52	struct list_head queue_list;
	53
	54	void (dtor)(struct io_context ); /* destructor */
	55	void (exit)(struct io_context ); /* called on task exit */
	56	};
	57
	58	/*
d38ecf93 JA	59	* I/O subsystem state of the associated processes. It is refcounted
d38ecf93 JA	60	* and kmalloc'ed. These could be shared between processes.
fd0928df JA	61	*/
	62	struct io_context {
	63	atomic_t refcount;
d38ecf93 JA	64	atomic_t nr_tasks;
	65
	66	/* all the fields below are protected by this lock */
	67	spinlock_t lock;
fd0928df JA	68
	69	unsigned short ioprio;
	70	unsigned short ioprio_changed;
	71
	72	/*
	73	* For request batching
	74	*/
	75	unsigned long last_waited; /* Time last woken after wait for request */
	76	int nr_batch_requests; /* Number of requests left in the batch */
	77
	78	struct as_io_context *aic;
4ac845a2	79	struct radix_tree_root radix_root;
fd0928df JA	80	void *ioc_data;
	81	};
	82
d38ecf93 JA	83	static inline struct io_context ioc_task_link(struct io_context ioc)
	84	{
	85	/*
	86	* if ref count is zero, don't allow sharing (ioc is going away, it's
	87	* a race).
	88	*/
	89	if (ioc && atomic_inc_not_zero(&ioc->refcount))
	90	return ioc;
	91
	92	return NULL;
	93	}
	94
fd0928df	95	#endif