[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;

	unsigned long ttime_total;
	unsigned long ttime_samples;
	unsigned long ttime_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_long_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_long_inc_not_zero(&ioc->refcount)) {
		atomic_inc(&ioc->nr_tasks);
		return ioc;
	}

	return NULL;
}

#ifdef CONFIG_BLOCK
int put_io_context(struct io_context *ioc);
void exit_io_context(void);
struct io_context *get_io_context(gfp_t gfp_flags, int node);
struct io_context *alloc_io_context(gfp_t gfp_flags, int node);
void copy_io_context(struct io_context **pdst, struct io_context **psrc);
#else
static inline void exit_io_context(void)
{
}

struct io_context;
static inline int put_io_context(struct io_context *ioc)
{
	return 1;
}
#endif

#endif
Commit	Line	Data
fd0928df JA	1	#ifndef IOCONTEXT_H
	2	#define IOCONTEXT_H
	3
4ac845a2	4	#include <linux/radix-tree.h>
34e6bbf2	5	#include <linux/rcupdate.h>
4ac845a2	6
fd0928df JA	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 {
fd0928df	35	void *key;
4ac845a2	36	unsigned long dead_key;
fd0928df JA	37
	38	struct cfq_queue *cfqq[2];
	39
	40	struct io_context *ioc;
	41
	42	unsigned long last_end_request;
fd0928df JA	43
	44	unsigned long ttime_total;
	45	unsigned long ttime_samples;
	46	unsigned long ttime_mean;
	47
fd0928df	48	struct list_head queue_list;
ffc4e759	49	struct hlist_node cic_list;
fd0928df JA	50
	51	void (dtor)(struct io_context ); /* destructor */
	52	void (exit)(struct io_context ); /* called on task exit */
34e6bbf2 FC	53
34e6bbf2 FC	54	struct rcu_head rcu_head;
fd0928df JA	55	};
	56
	57	/*
d38ecf93 JA	58	* I/O subsystem state of the associated processes. It is refcounted
d38ecf93 JA	59	* and kmalloc'ed. These could be shared between processes.
fd0928df JA	60	*/
fd0928df JA	61	struct io_context {
d9c7d394	62	atomic_long_t refcount;
d38ecf93 JA	63	atomic_t nr_tasks;
	64
	65	/* all the fields below are protected by this lock */
	66	spinlock_t lock;
fd0928df JA	67
	68	unsigned short ioprio;
	69	unsigned short ioprio_changed;
	70
	71	/*
	72	* For request batching
	73	*/
	74	unsigned long last_waited; /* Time last woken after wait for request */
	75	int nr_batch_requests; /* Number of requests left in the batch */
	76
	77	struct as_io_context *aic;
4ac845a2	78	struct radix_tree_root radix_root;
ffc4e759	79	struct hlist_head cic_list;
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	*/
d9c7d394	89	if (ioc && atomic_long_inc_not_zero(&ioc->refcount)) {
cbb4f264	90	atomic_inc(&ioc->nr_tasks);
d38ecf93	91	return ioc;
d237e5c7	92	}
d38ecf93 JA	93
	94	return NULL;
	95	}
	96
da9cbc87 JA	97	#ifdef CONFIG_BLOCK
	98	int put_io_context(struct io_context *ioc);
	99	void exit_io_context(void);
	100	struct io_context *get_io_context(gfp_t gfp_flags, int node);
	101	struct io_context *alloc_io_context(gfp_t gfp_flags, int node);
	102	void copy_io_context(struct io_context pdst, struct io_context psrc);
	103	#else
	104	static inline void exit_io_context(void)
	105	{
	106	}
	107
	108	struct io_context;
	109	static inline int put_io_context(struct io_context *ioc)
	110	{
	111	return 1;
	112	}
	113	#endif
	114
fd0928df	115	#endif