DESIGN ALGORITHMS FOR ASYNCHRONOUS WRITE OPERATIONS IN DISK-BUFFER-CACHE MEMORY

This article introduces new algorithms for asynchronous operations in disk-buffer-cache memory. These algorithms allow for writing files into the buffer cache by the processes. The number of active processes in the system and the length of the queue to the disk-buffer cache are considered in the algorithm design. This information is obtained dynamically during the execution of the algorithms. The performance of the operations on the buffer cache is improved by using the algorithms, which allow for writing the contents of the buffer cache to the disk depending on the system load and the write activity. The elapsed time of writing a file into the buffer cache is calculated. The waiting time to start writing a file is also considered. It is shown that the elapsed time of writing a file decreases using the algorithms, which write the blocks to the disk depending on the rate of write operations and the number of active processes in the system. The time for a block to become available for update in the buffer cache is given. The number of blocks available for update in the buffer cache is derived. The performance of the algorithms is compared. It is shown that the proposed algorithms allow for better performance than an algorithm that does not use information about the system load.