The Linux-SRT integrated multimedia operating system: bringing QoS to the desktop

Current operating systems are being used to perform tasks for which they were not designed. Architectures conceived to provide fairness in timesharing systems are being asked to support applications needing quality of service (QoS) guarantees. Past research has focused on specialised multimedia operating systems; QoS features are now ready to be incorporated in mainstream operating systems, allowing existing applications to be used without modification. Appropriate user interface features are essential if QoS is to become widely used. We present the Linux-SRT (Ingram, 2000) system, a version of Linux enhanced with support for predictable scheduling and QoS management. It is binary compatible with standard Linux: existing applications can benefit from QoS without being modified in any way. CPU and disk bandwidth are scheduled, and scheduling policies are propagated to servers. Automated control and management features simplify the use of advanced features. Linux-SRT has been proven in everyday use. It provides an integrated system approach to QoS for multiple devices, from low-level scheduling to high-level user tools