Context-Aware File I/O Management System for Mobile Devices

Mobile devices such as smartphones and tablets have become widespread, and studies are being conducted to improve the convenience of smartphone users. The I/O performance is considered an important factor affecting the quality of the smartphone user experience. Therefore, methods for retaining applications with a high launch frequency in the main memory, improving the I/O stack of the smartphone operating system, and a new file system for improving the I/O performance have been actively studied. However, there is no information sharing system between the I/O stacks in a smartphone operating system. Existing studies suffer from limitations in improving the file I/O performance because the upper- and lower-layer information of the I/O stack was not considered simultaneously. In this paper, we propose a context-aware file I/O management system (CAFIO) for analyzing context information collected from various layers of the I/O stack and sharing them between the layers. CAFIO collects smartphone application usage patterns and combines them with the lower-layer I/O information to improve the launch speed and I/O latency of an application. CAFIO exhibits average improvements of 26% in application launch time and 45% in cache hit ratio, as well as a read speed 63% faster than that of existing file I/O management systems.