Scheduling Stochastically-Executing Soft Real-Time Tasks: A Multiprocessor Approach Without Worst-Case Execution Times
نویسندگان
چکیده
We introduce a scheduling method where stochasticallyexecuting soft real-time tasks are assigned to simple sporadic servers with predetermined execution budgets. We show that using this method, any task system whose average-case total utilization is less than the number of processors can be scheduled so that tardiness is bounded in the average case. The constraint on average-case utilization is extremely mild compared to constraints on worst-case utilization because in multiprocessor systems, worst-case execution times may be orders of magnitude higher than average-case execution times. Unlike in previous work, the derived tardiness bound depends only on the mean and variance of execution times. For soft realtime systems where bounded tardiness is acceptable, this result eliminates the need for timing analysis to determine worst-case execution times.
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