关键词: 多线程, 文件预取, 多预取点, Linux内核

Abstract: To solve the problem that the prefetching algorithm of the current Linux kernel might mistakenly prefetch blocks under the circumstances of multithreading, according to the characteristics of disk file reading in a multi-threaded environment, this paper proposed a file prefetching algorithm with multiple prefetching points. On the basis of the original prefetching algorithm and in combination with the data access patterns of applications, the algorithm was implemented on the page caching layer of Linux. Through the experiments and analysis with IOzone, this proposed algorithm showed comparable performance with the existing algorithm of Linux in the single threaded environment and in a multithreaded one, and it took less time by 1/3 at least. The proposed algorithm helps to improve the I/O parallelism, thereby enhancing the entire computer system parallelism.