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

#ifndef IOCONTEXT_H
#define IOCONTEXT_H

#include <linux/radix-tree.h>
#include <linux/rcupdate.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;
	struct hlist_node cic_list;

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

	struct rcu_head rcu_head;
};

/*
 * 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;
	struct hlist_head cic_list;
	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
	1	#ifndef IOCONTEXT_H
	2	#define IOCONTEXT_H
	3
	4	#include <linux/radix-tree.h>
	5	#include <linux/rcupdate.h>
	6
	7	/*
	8	* This is the per-process anticipatory I/O scheduler state.
	9	*/
	10	struct as_io_context {
	11	spinlock_t lock;
	12
	13	void (dtor)(struct as_io_context aic); /* destructor */
	14	void (exit)(struct as_io_context aic); /* called on task exit */
	15
	16	unsigned long state;
	17	atomic_t nr_queued; /* queued reads & sync writes */
	18	atomic_t nr_dispatched; /* number of requests gone to the drivers */
	19
	20	/* IO History tracking */
	21	/* Thinktime */
	22	unsigned long last_end_request;
	23	unsigned long ttime_total;
	24	unsigned long ttime_samples;
	25	unsigned long ttime_mean;
	26	/* Layout pattern */
	27	unsigned int seek_samples;
	28	sector_t last_request_pos;
	29	u64 seek_total;
	30	sector_t seek_mean;
	31	};
	32
	33	struct cfq_queue;
	34	struct cfq_io_context {
	35	void *key;
	36	unsigned long dead_key;
	37
	38	struct cfq_queue *cfqq[2];
	39
	40	struct io_context *ioc;
	41
	42	unsigned long last_end_request;
	43	sector_t last_request_pos;
	44
	45	unsigned long ttime_total;
	46	unsigned long ttime_samples;
	47	unsigned long ttime_mean;
	48
	49	unsigned int seek_samples;
	50	u64 seek_total;
	51	sector_t seek_mean;
	52
	53	struct list_head queue_list;
	54	struct hlist_node cic_list;
	55
	56	void (dtor)(struct io_context ); /* destructor */
	57	void (exit)(struct io_context ); /* called on task exit */
	58
	59	struct rcu_head rcu_head;
	60	};
	61
	62	/*
	63	* I/O subsystem state of the associated processes. It is refcounted
	64	* and kmalloc'ed. These could be shared between processes.
	65	*/
	66	struct io_context {
	67	atomic_t refcount;
	68	atomic_t nr_tasks;
	69
	70	/* all the fields below are protected by this lock */
	71	spinlock_t lock;
	72
	73	unsigned short ioprio;
	74	unsigned short ioprio_changed;
	75
	76	/*
	77	* For request batching
	78	*/
	79	unsigned long last_waited; /* Time last woken after wait for request */
	80	int nr_batch_requests; /* Number of requests left in the batch */
	81
	82	struct as_io_context *aic;
	83	struct radix_tree_root radix_root;
	84	struct hlist_head cic_list;
	85	void *ioc_data;
	86	};
	87
	88	static inline struct io_context ioc_task_link(struct io_context ioc)
	89	{
	90	/*
	91	* if ref count is zero, don't allow sharing (ioc is going away, it's
	92	* a race).
	93	*/
	94	if (ioc && atomic_inc_not_zero(&ioc->refcount))
	95	return ioc;
	96
	97	return NULL;
	98	}
	99
	100	#endif