Scheduler-Assisted Prefetching: Efficient Demand Paging for Embedded Systems

Embedded systems tend to use demand paging in order to provide more memory to applications in a cost-effective manner. However, demand paging drastically degrades the performance when the page fault rate is high. Prefetching has been known as a common remedy for page fault overhead. Although many prefetching mechanisms have been proposed, they are either effective only for specific page access patterns or too straight-forward to decrease a page fault rate to an acceptable level. We propose a scheduler-assisted prefetching mechanism which does not have such fundamental defects. As a proof of concept, our mechanism was completely implemented in Linux. We have also conducted a series of experiments to show its effectiveness. The experimental results showed a significant improvement: the number of the major page faults and the scheduling latency decreased by 30% and 51%, respectively.