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			121 lines
		
	
	
		
			2.6 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			121 lines
		
	
	
		
			2.6 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
| #ifndef IOCONTEXT_H
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| #define IOCONTEXT_H
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| 
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| #include <linux/radix-tree.h>
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| #include <linux/rcupdate.h>
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| 
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| /*
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|  * This is the per-process anticipatory I/O scheduler state.
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|  */
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| struct as_io_context {
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| 	spinlock_t lock;
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| 
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| 	void (*dtor)(struct as_io_context *aic); /* destructor */
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| 	void (*exit)(struct as_io_context *aic); /* called on task exit */
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| 
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| 	unsigned long state;
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| 	atomic_t nr_queued; /* queued reads & sync writes */
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| 	atomic_t nr_dispatched; /* number of requests gone to the drivers */
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| 
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| 	/* IO History tracking */
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| 	/* Thinktime */
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| 	unsigned long last_end_request;
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| 	unsigned long ttime_total;
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| 	unsigned long ttime_samples;
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| 	unsigned long ttime_mean;
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| 	/* Layout pattern */
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| 	unsigned int seek_samples;
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| 	sector_t last_request_pos;
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| 	u64 seek_total;
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| 	sector_t seek_mean;
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| };
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| 
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| struct cfq_queue;
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| struct cfq_io_context {
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| 	void *key;
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| 	unsigned long dead_key;
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| 
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| 	struct cfq_queue *cfqq[2];
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| 
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| 	struct io_context *ioc;
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| 
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| 	unsigned long last_end_request;
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| 	sector_t last_request_pos;
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| 
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| 	unsigned long ttime_total;
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| 	unsigned long ttime_samples;
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| 	unsigned long ttime_mean;
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| 
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| 	unsigned int seek_samples;
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| 	u64 seek_total;
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| 	sector_t seek_mean;
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| 
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| 	struct list_head queue_list;
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| 	struct hlist_node cic_list;
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| 
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| 	void (*dtor)(struct io_context *); /* destructor */
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| 	void (*exit)(struct io_context *); /* called on task exit */
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| 
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| 	struct rcu_head rcu_head;
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| };
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| 
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| /*
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|  * I/O subsystem state of the associated processes.  It is refcounted
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|  * and kmalloc'ed. These could be shared between processes.
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|  */
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| struct io_context {
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| 	atomic_t refcount;
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| 	atomic_t nr_tasks;
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| 
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| 	/* all the fields below are protected by this lock */
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| 	spinlock_t lock;
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| 
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| 	unsigned short ioprio;
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| 	unsigned short ioprio_changed;
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| 
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| 	/*
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| 	 * For request batching
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| 	 */
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| 	unsigned long last_waited; /* Time last woken after wait for request */
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| 	int nr_batch_requests;     /* Number of requests left in the batch */
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| 
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| 	struct as_io_context *aic;
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| 	struct radix_tree_root radix_root;
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| 	struct hlist_head cic_list;
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| 	void *ioc_data;
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| };
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| 
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| static inline struct io_context *ioc_task_link(struct io_context *ioc)
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| {
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| 	/*
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| 	 * if ref count is zero, don't allow sharing (ioc is going away, it's
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| 	 * a race).
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| 	 */
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| 	if (ioc && atomic_inc_not_zero(&ioc->refcount)) {
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| 		atomic_inc(&ioc->nr_tasks);
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| 		return ioc;
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| 	}
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| 
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| 	return NULL;
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| }
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| 
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| #ifdef CONFIG_BLOCK
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| int put_io_context(struct io_context *ioc);
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| void exit_io_context(void);
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| struct io_context *get_io_context(gfp_t gfp_flags, int node);
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| struct io_context *alloc_io_context(gfp_t gfp_flags, int node);
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| void copy_io_context(struct io_context **pdst, struct io_context **psrc);
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| #else
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| static inline void exit_io_context(void)
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| {
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| }
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| 
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| struct io_context;
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| static inline int put_io_context(struct io_context *ioc)
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| {
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| 	return 1;
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| }
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| #endif
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| 
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| #endif
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