Real-Time Disk Scheduling in a Mixed-Media File System. Information Systems

摘要

This paper presents our real-time disk scheduler called the L scheduler, whichoptimizes unscheduled best-effort disk requests by giving priority to best-effort disk requests while meeting real-time request deadlines. Our scheduler tries to execute real-time disk requests as much as possible in the background. Only when real-time request deadlines are endangered, our scheduler gives priority to real-time disk requests. The L disk scheduler is part of our mixed-media file system called Clockwise. An essential part of our work are extensive and detailed raw disk performance measurements. These raw performance measurements are used by the L disk scheduler for its real-time schedulability analysis and to decide whether scheduling a best-effort request before a real-time request violates real-time constraints.