UCSC-CRL-04-11: Efficient Soft Real-Time Processing in an Integrated System

09/15/2004 09:00 AM
Computer Science
The rapidly increasing user demands on more powerful
computing platforms and application capabilities requires
modern operating systems capable of scheduling multiple
classes of processes in an integrated way, in which real-time
applications are guaranteed to meet their time constraints
by using worst case resource reservation and non-critical
applications (such as soft real-time) execute in degraded
performance by using average case reservation. How-
ever these reservation-based resource allocation mecha-
nisms may overbook resources so that the system may waste
large amounts of resources in such a way that the slack time
is not efficiently consumed. Also, overhead caused by best-
effort processes is usually not considered. In this paper,
we present for such an integrated system a flexible and ef-
ficient resource management mechanism for soft real-time
processes in such a way that the slack time is better utilized
and a single monolithic server for all best-effort processes
to reduce the dynamic scheduling overhead. The simulation
results show that our flexible slack time management mech-
anism for soft real-time processes can result in significantly
performance improvement in terms of reducing the deadline
miss ratio and tardiness.