This paper introduces probabilistic analysis for fixed priority preemptive scheduling of mixed criticality systems on a uniprocessor using the Adaptive Mixed Criticality (AMC) and Static Mixed Criticality (SMC) schemes. We compare this analysis to the equivalent deterministic methods, highlighting the performance gains that can be obtained by utilising more detailed information about worst-case...

In this paper, we model a call center as a preemptive-resume priority queue with time-varying arrival rates and two priority classes of customers. The low priority customers have a dynamic priority where they become high priority if their waiting-time in queue exceeds a given service-level time. The performance of the call center is measured by the mean number in system for the two customer cla...

An OpMiGua node integrates a packet switch for low priority traffic and a circuit switch for high priority traffic. Both traffic classes share the same input and output ports using time division multiplexing, but absolute priority is given to circuit switched packets. The circuit switched packets do not experience contention at output ports and are not subject to delay jitter; hence a guarantee...

In this paper we analyze an MN/MN/1 queueing system with N customer classes and preemptive priorities between classes, by using matrix-analytic techniques. This leads to an exact method for the computation of the steady state joint queue length distribution. We also indicate how the method can be extended to models with multiple servers and other priority rules.

A number of multi-priority jobs are to be processed on two heterogeneous processors. Of the jobs waiting in the buffer, jobs with the highest priority have the first option of being dispatched for processing when a processor becomes available. On each processor, the processing times of the jobs within each priority class are stochastic, but have known distributions with decreasing mean residual...

We model a call center as a preemptive-resume priority queue with time-varying arrival rates and two priority classes of customers. The low priority customers have a dynamic priority where they become high priority if their waitingtime exceeds a given service-level time. The performance of the call center is measured by the mean number in system for the two customer classes. A fluid approximati...

In many industrial systems, design complexity is partly reduced by the use of non-preemptive message passing or execution. Doing so, context switch overheads are diminished and resource sharing mechanisms are simplified. However, in a mixedcriticality system, long blocking time caused by non-preemptive execution of a task which has lower priority than some other high criticality (HC) tasks migh...

This paper introduces an analytical method for approximating the performance of a two-class priority M/M/1 system. The system is fully non-preemptive. More specifically, the prioritized class-1 jobs are real-time and served with the non-preemptive earliest-deadline-first (EDF) policy, but despite their priority cannot preempt any non real-time class-2 job. The waiting class-2 jobs can only be s...

0 50 100 Interarrival Delay Jitter Offered Load Percentage Figure 15: A three-dimensional plot of the Delay Jitter histogram at the destination for four VBR connections for diierent background non-QoS (datagram) loads with preemptive priority to QoS Virtual Channels. Note the log scale for the delay jitter in byte times at the destination. we have presented and evaluated several diierent approa...

In present era, one of the most important resources of computer machine is CPU. With the increasing number of application, there exist a large number of processes in the computer system at the same time. Many processes in system simultaneously raise a challenging circumstance of managing the CPU in such a manner that the CPU utilization and processes execution gets optimal performance. The worl...