Abstract: The read and write performances of Linux vary while accessed by different file record sizes.The read and write performances of Linux are low at certain accessing file record sizes.The algorithm in Page Cache is one of the causes of this problem.Based on the analysis of the influence of different accessing file record sizes on the performance of Page Cache，this paper developes an efficient self-adjusting scheme to improve read and write performances of Linux.The scheme considers prefetching policy’s influence on replacement algorithm and increases replacement algorithm’s adaptability to vary accessing file record sizes.Experimentally，the scheme is efficient to improve read and write performances of Linux.

Key words: Linux, Page Cache, replacement algorithm, prefetching

摘要： Linux系统在被不同大小的数据块访问时，系统读写性能有差异。在少数特定访问数据块大小的应用中，Linux系统读写性能较差。文件Cache算法的性能是导致该问题的原因之一。在分析访问数据块大小对文件Cache算法性能的影响的基础上，提出了一种文件Cache自适应策略。该策略考虑了预取算法对于页面置换算法的影响，增强了页面置换算法对访问数据块大小变化的适应性，达到了提高Linux系统读写性能的目标。Linux系统读写性能测试实验表明，该策略可以使Linux系统在被不同大小的数据块访问时保持稳定且更优的读写性能。

关键词: Linux, 文件Cache, 页面置换算法, 预取算法