Efficient preemptions in the scheduling of real time systems cause optimal overhead in parallel computing systems. Periodic and sporadic tasks are exists in the real time systems. The periodic tasks may be divided into the synchronous and asynchronous categories. The management of the resource sharing in the parallel computing can be powerfully achieved by preemptive scheduling. Fast preemption...

Many disciplines have been proposed for scheduling and processor allocation in multiprogrammed multiprocessors for parallel processing. These have been, for the most part, designed and evaluated for workloads having relatively low variability in service demand. But with reports that variability in service demands at high performance computing centers can actually be quite high, these discipline...

Preemption in multi-mode Resource-constrained project scheduling problem Zahra Zare* Department of Industrial Engineering Najafabad Branch, Islamic Azad University, Isfahan, Iran Postal Code: 71767-13763, Unit 3, No 142, 6 Alley, South Bahonar St., Shiraz, Iran Abdulreza Naddaf Department of Management Shiraz University, Shiraz, Iran Maysam Ashrafzadeh Department of Industrial Engineering Najaf...

Project expediting is often viewed as a corrective action taken in response to prior scheduling errors and is usually applied in the later stages of projects when it appears that predefined due dates will not be met. However, large-scale projects with uncertain activity durations tend to have numerous probabilistic network paths with complex interactions that require some level of expediting to...

In this paper, we consider the semi-online preemptive scheduling problem with known largest job sizes on two uniform machines. Our goal is to maximize the continuous period of time (starting from time zero) when both machines are busy, which is equivalent to maximizing the minimum machine completion time if idle time is not introduced. We design optimal deterministic semi-online algorithms for ...

Recent Internet traffic measurements show that 60% of the total packets are short packets, which include TCP acknowledgment and control segments. These short packets make a great impact on the performance of TCP. Unfortunately, short packets suffer from large delay due to serving long data packets in switches running in the packet mode, i.e. a packet is switched in its entirety. To optimize TCP...

The most important requirement for real-time systems is the capability to support the timely execution of applications. Real-time scheduling over a single processor has been widely studied in the last thirty years, and it has been proven that the non-preemptive version of Earliest Deadline First (EDF) algorithm is optimal [1], in the sense that if a set of tasks is schedulable, it is also sched...

Our work required a model for scheduling real-time tasks that extended the state of the art, supporting a flexible mix of preemptive and non-preemptive scheduling. Mixing these two kinds of scheduling is useful because preemption permits flexible allocation of CPU time while nonpreemptive scheduling has many benefits in software engineering (since race conditions become much more difficult to c...

In real-time systems response to a request from a controlled object must be correct and timely. Any late response to a request from such a device might lead to a catastrophy. The possibility of a task overrun, i.e., missing the deadline for completing a requested task, must be checked and removed during the design of such systems. Safe design of real-time systems running periodic tasks under th...

Machine scheduling admits two options to process jobs. In a preemptive mode processing may be interrupted and resumed later even on a different machine. In a nonpreemptive mode interruptions are not allowed. Usually, the possibility to preempt jobs leads to better performance values. However, also examples exist where preemptions do not improve the performance. This paper gives an overview of e...