Summary: LITMUS RT : A Testbed for Empirically Comparing RealTime
Multiprocessor Schedulers #
John M. Calandrino, Hennadiy Leontyev, Aaron Block, UmaMaheswari C. Devi, and James H. Anderson
Department of Computer Science, The University of North Carolina at Chapel Hill
We present a realtime, Linuxbased testbed called
LITMUS RT , which we have developed for empirically eval
uating multiprocessor realtime scheduling algorithms. We
also present the results from such an evaluation, in which
partitioned earliestdeadlinefirst (EDF) scheduling, pre
emptive and nonpreemptive global EDF scheduling, and two
variants of the global PD 2 Pfair algorithm were considered.
The tested algorithms were compared based on both raw
performance and schedulability (with real overheads con
sidered) assuming either hard or softrealtime constraints.
To our knowledge, this paper is the first attempt by anyone
to compare partitioned and global realtime scheduling ap
proaches using empirical data.
Interest in techniques for effectively scheduling realtime