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对双头磁盘系统模型和调度算法进行实时化扩展，设计了三种实时调度算法：最早截止期优先（ＥＤＦ）算法，可满足的最早截止期优先（Ｆ－ＥＤＦ）算法和忽视超期限请求（ＩＧＭ－ＥＤＦ）算法．由于这三种算法充分考虑了Ｉ／Ｏ请求的截止期限，使双头磁盘系统能满足更多的实时Ｉ／Ｏ请求．实时调度算法的性能模拟实验表明：实时调度算法比非实时算法能更好地满足实时Ｉ／Ｏ请求的期限要求．三种实时调度算法中，ＩＧＭ－ＥＤＦ的性能最好，它很适用于硬实时应用；Ｆ－ＥＤＦ算法的性能次之，它最适合于软实时应用．
In this paper, three kinds of real-time scheduling algorithms are designed, including the EDF algorithm, the satisfiable F-EDF algorithm and the neglect of deadline request IGM-EDF) algorithm. Because these three algorithms take full account of the deadline for I / O requests, the two-headed disk system can satisfy more real-time I / O requests. Real-time scheduling algorithm performance simulation experiments show that: real-time scheduling algorithm can better meet the real-time I / O request deadline requirements than non-real-time algorithm. Among the three real-time scheduling algorithms, IGM-EDF has the best performance, which is very suitable for hard real-time applications. F-EDF algorithm is second in performance, which is most suitable for soft real-time applications.