再探讨虚拟存储中的置换算法

Rediscussion on the displacement algorithms in the virtual store

近年来 ,随着硬件技术和生产水平的发展 ,内存的成本迅速下降 ,而容量一直不断扩大 ,但是 ,仍不能满足各种软件对存储空间急剧增长的需求 .因此 ,对内存的有效管理仍是现代操作系统中的十分重要的问题 .本文再次阐述了虚拟存储中的置换算法各自的基本思想、实现算法、并比较它们的优缺点 ,以及在同一置换算法中对该算法的几种不同分析理解方法 .最后把置换算法进行了综合性性能分析 ,如何才能把缺页率保持在一个合理的水平上 .

Accompanying with the development of hardware technology and productive level, the cost of inner memories is reduced rapidly and the capacity is extended continuously. But these can't meet the demands of different software for the sharp growth of memory space. So the perfect management for inner memories is still an important problem in the modern operating system. Several displacement algorithms in the virtual store and their basic ideas, realization algorithms are presented. Their advantages and disadvantages and several different analysis comprehension methods for every displacement algorithm are compared. Finally, the comprehensive performances of displacement algorithms are analyzed, and the method of keeping the rate of missing pages on a reasonable level is obtained.