Condor is a batch job system that, unlike many other scheduling systems, allows users to access both dedicated computers and computers that are not always available, perhaps because they are used as desktop computers or are not under local control. This introduces a number of problems, some of which are solved by Condor’s preemptive resume scheduling, which is the focus of this paper. Preemptiv...

We consider a model for scheduling under uncertainty. In this model, we combine the main characteristics of online and stochastic scheduling in a simple and natural way. Job processing times are assumed to be stochastic, but in contrast to traditional stochastic scheduling models, we assume that jobs arrive online, and there is no knowledge about the jobs that will arrive in the future. The mod...

We consider basic problems of non-preemptive scheduling on uniformly related machines. For a given schedule, defined by a partition of the jobs into m subsets corresponding to the m machines, Ci denotes the completion time of machine i. Our goal is to find a schedule which minimizes or maximizes m

CPU scheduling is the basis of multi programmed operating system. The idea of multiprogramming is relatively simple, if a process (job) is waiting for an I/O request, then CPU switches from one job to another job so that CPU is always busy and computer becomes more productive. Scheduling is a fundamental operating system function, almost all computer resources are scheduled before use. The CPU ...

We present a new online algorithm, MR, for non-preemptive scheduling of jobs with known processing times on m identical machines which beats the best previous algorithm for m 64. For m ! 1 its competitive ratio approaches 1 + p 1+ln 2 2 < 1:9201.

We formalise the behaviour of non-preemptive, real-time, multi-tasking systems by expressing the computational components assumed by real-time scheduling theory in a trace-based notation. The model is suitable as a target implementation domain for dataaow reenements, amenable to formal schedulability analysis, and implementable in a concurrent real-time programming language.

The analysis of fixed priority preemptive scheduling has been extended in various ways to improve its usefulness for the design of real-time systems. In this paper, we define the layered preemptive priority scheduling policy which generalizes fixed preemptive priorities by combination with other policies in a layered structure. In particular, the combination with the Round Robin scheduling poli...

Preemptive multi-tasking is a commonly used architecture for designing and implementing embedded real-time software. However, preemptive multi-tasking comes with its own costs. These costs include overheads due to preemptions and context-switches that result in waste of CPU bandwidth. Also, each task incurs a memory cost largely due to the need to maintain a separate stack for each task. These ...

Multiprocessor task scheduling problem is a pressing that affects systems' performance and still being investigated by the researchers. Finding optimal schedules considered to be computationally hard problem. Recently, researchers have used fuzzy logic in field of achieve performance, but this area research not well investigated. In addition, there are various algorithms most them often perform...

The problem considered is the non-preemptive scheduling of independent jobs that consume a resource (which non-renewable and replenished regularly) on parallel uniformly related machines. input defines speed machines, size jobs, quantity required by quantities, replenishment dates resource. Every job can start processing only after allocated to job. objective function generalization makespan mi...