Summary: 1
Adapting Pfair Scheduling for Symmetric
Multiprocessors
Philip Holman and James H. Anderson
Abstract--- We consider the implementation of a Pfair real­
time scheduler on a symmetric multiprocessor (SMP). Although
SMPs are in many ways well­suited for Pfair scheduling, ex­
perimental results presented herein suggest that bus contention
resulting from the simultaneous scheduling of all processors can
substantially degrade performance. To correct this problem, we
propose a staggered model for Pfair scheduling that strives to
improve performance by more evenly distributing bus traffic over
time. Additional simulations and experiments with a scheduler
prototype are presented to demonstrate the effectiveness of the
staggering approach. In addition, we discuss other techniques for
improving performance while maintaining worst­case predictability.
Finally, we present an efficient scheduling algorithm to support
the proposed model and briefly explain how existing Pfair results
apply to staggered scheduling.
Keywords: SMP, Pfairness, real­time, scheduling, bus, multi­

Source: Anderson, James - Department of Computer Science, University of North Carolina at Chapel Hill

Collections: Computer Technologies and Information Sciences