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—A multiprocessor scheduling algorithm named U-EDF, was presented in [1] for the scheduling of periodic tasks with implicit deadlines. It was claimed that U-EDF is optimal for periodic tasks (i.e., it can meet all deadlines of every schedulable task set) and extensive simulations showed a drastic improvement in the number of task preemptions and migrations(More)
In real-time systems, there are two distinct trends for scheduling task sets on unicore systems: non-preemptive and preemptive scheduling. Non-preemptive scheduling is obviously not subject to any preemption delay but its schedulability may be quite poor, whereas fully preemptive scheduling is subject to preemption delay, but benefits from a higher(More)
The last decade has witnessed a major shift towards the deployment of embedded applications on multi-core platforms. However, real-time applications have not been able to fully benefit from this transition, as the computational gains offered by multi-cores are often offset by performance degradation due to shared resources, such as main memory. To(More)
Nowadays, many real-time operating systems discretize the time relying on a system time unit. To take this behavior into account, real-time scheduling algorithms must adopt a discrete-time model in which both timing requirements of tasks and their time allocations have to be integer multiples of the system time unit. That is, tasks cannot be executed for(More)
It is a known fact that processes running concurrently on different cores in a multicore environment interfere with each other on the processor shared resources. The contention on these shared resources considerably slows down the execution on every core since sometimes the cores must stall while their requests to access the resources are being served. But(More)
The current industry trend is towards using Commercially available Off-The-Shelf (COTS) based multicores for developing real-time embedded systems, as opposed to the usage of custom-made hardware. In typical implementation of such COTS-based multicores, multiple cores access the main memory via a shared bus. This often leads to contention on this shared(More)
We consider the global and preemptive scheduling problem of multi-mode real-time systems upon identical multi-processor platforms. Since it is a multi-mode system, the system can change from one mode to another such that the current task set is replaced with a new task set. Ensuring that deadlines are met requires not only that a schedula-bility test is(More)
COTS-based multicores are now the preferred choice for hosting embedded applications owing to their immense computational capabilities, small form factor and low power consumption. Many of these embedded applications have real-time requirements and real-time system designers must be able assess them for their predictability and provide guarantees (at design(More)
Owing to the current trends for higher performance and the ever growing availability of multiprocessors in the embedded computing (EC) domain, there is nowadays a strong push towards the parallelization of modern embedded applications. Several real-time task models have recently been proposed to capture different forms of parallelism. However, they do not(More)