[linux-2.6-block.git] / include / linux / iocontext.h

#ifndef IOCONTEXT_H
#define IOCONTEXT_H

#include <linux/radix-tree.h>
#include <linux/rcupdate.h>

struct cfq_queue;
struct cfq_ttime {
	unsigned long last_end_request;

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

struct cfq_io_context {
	void *key;

	struct cfq_queue *cfqq[2];

	struct io_context *ioc;

	struct cfq_ttime ttime;

	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;

#if defined(CONFIG_BLK_CGROUP) || defined(CONFIG_BLK_CGROUP_MODULE)
	unsigned short cgroup_changed;
#endif

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

	struct radix_tree_root radix_root;
	struct hlist_head cic_list;
	void __rcu *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;
}

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

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	7	struct cfq_queue;
383cd721 SL	8	struct cfq_ttime {
	9	unsigned long last_end_request;
	10
	11	unsigned long ttime_total;
	12	unsigned long ttime_samples;
	13	unsigned long ttime_mean;
	14	};
	15
fd0928df	16	struct cfq_io_context {
fd0928df JA	17	void *key;
	18
	19	struct cfq_queue *cfqq[2];
	20
	21	struct io_context *ioc;
	22
383cd721	23	struct cfq_ttime ttime;
fd0928df	24
fd0928df	25	struct list_head queue_list;
ffc4e759	26	struct hlist_node cic_list;
fd0928df JA	27
	28	void (dtor)(struct io_context ); /* destructor */
	29	void (exit)(struct io_context ); /* called on task exit */
34e6bbf2 FC	30
34e6bbf2 FC	31	struct rcu_head rcu_head;
fd0928df JA	32	};
	33
	34	/*
d38ecf93 JA	35	* I/O subsystem state of the associated processes. It is refcounted
d38ecf93 JA	36	* and kmalloc'ed. These could be shared between processes.
fd0928df JA	37	*/
fd0928df JA	38	struct io_context {
d9c7d394	39	atomic_long_t refcount;
d38ecf93 JA	40	atomic_t nr_tasks;
	41
	42	/* all the fields below are protected by this lock */
	43	spinlock_t lock;
fd0928df JA	44
	45	unsigned short ioprio;
	46	unsigned short ioprio_changed;
	47
67523c48	48	#if defined(CONFIG_BLK_CGROUP) \|\| defined(CONFIG_BLK_CGROUP_MODULE)
31e4c28d VG	49	unsigned short cgroup_changed;
	50	#endif
	51
fd0928df JA	52	/*
	53	* For request batching
	54	*/
fd0928df	55	int nr_batch_requests; /* Number of requests left in the batch */
58c24a61	56	unsigned long last_waited; /* Time last woken after wait for request */
fd0928df	57
4ac845a2	58	struct radix_tree_root radix_root;
ffc4e759	59	struct hlist_head cic_list;
4d2deb40	60	void __rcu *ioc_data;
fd0928df JA	61	};
fd0928df JA	62
d38ecf93 JA	63	static inline struct io_context ioc_task_link(struct io_context ioc)
	64	{
	65	/*
	66	* if ref count is zero, don't allow sharing (ioc is going away, it's
	67	* a race).
	68	*/
d9c7d394	69	if (ioc && atomic_long_inc_not_zero(&ioc->refcount)) {
cbb4f264	70	atomic_inc(&ioc->nr_tasks);
d38ecf93	71	return ioc;
d237e5c7	72	}
d38ecf93 JA	73
	74	return NULL;
	75	}
	76
b69f2292	77	struct task_struct;
da9cbc87 JA	78	#ifdef CONFIG_BLOCK
da9cbc87 JA	79	int put_io_context(struct io_context *ioc);
b69f2292	80	void exit_io_context(struct task_struct *task);
da9cbc87 JA	81	struct io_context *get_io_context(gfp_t gfp_flags, int node);
da9cbc87 JA	82	struct io_context *alloc_io_context(gfp_t gfp_flags, int node);
da9cbc87	83	#else
b69f2292	84	static inline void exit_io_context(struct task_struct *task)
da9cbc87 JA	85	{
	86	}
	87
	88	struct io_context;
	89	static inline int put_io_context(struct io_context *ioc)
	90	{
	91	return 1;
	92	}
	93	#endif
	94
fd0928df	95	#endif