elevator.h.txt

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相关文件
	/drivers/block/ll_rw_blk.c	//只在这个文件中被实用


**********************基本数据结构***************************************
(1)struct elevator_s {
        int read_latency;
        int write_latency;
        int max_bomb_segments;

        elevator_merge_fn *elevator_merge_fn;
        elevator_merge_cleanup_fn *elevator_merge_cleanup_fn;
        elevator_merge_req_fn *elevator_merge_req_fn;

        unsigned int queue_ID;
   };

//预先定义了两种电梯合并算法，默认是第二种
#define ELEVATOR_NOOP                                                   \
((elevator_t) {                                                         \
        0,                              /* read_latency */              \
        0,                              /* write_latency */             \
        0,                              /* max_bomb_segments */         \
        elevator_noop_merge,            /* elevator_merge_fn */         \
        elevator_noop_merge_cleanup,    /* elevator_merge_cleanup_fn */ \
        elevator_noop_merge_req,        /* elevator_merge_req_fn */     \
        })

#define ELEVATOR_LINUS                                                  \
((elevator_t) {                                                         \
        8192,                           /* read passovers */            \
        16384,                          /* write passovers */           \
        6,                              /* max_bomb_segments */         \
        elevator_linus_merge,           /* elevator_merge_fn */         \
        elevator_linus_merge_cleanup,   /* elevator_merge_cleanup_fn */ \
        elevator_linus_merge_req,       /* elevator_merge_req_fn */     \
        })

*************************************************************************


*****************************基本函数************************************
(1)static inline int elevator_request_latency(elevator_t * elevator, int rw)
	//根据rw的值返回elevator中的read_latency或者write_latency
*************************************************************************