理解内存页面调度的机制，在模拟实现FIFO、LRU、OPT算法的基础上，比较各种置换算法的效率和优劣，从而了解虚拟储存的实现过程-Understanding of the mechanisms of memory paging, on the basis of the simulation to achieve FIFO, LRU, OPT algorithm, compare the pros and cons of replacement algorithm efficiency and to understand the implementation process virtual storage