Improved Conditions for Bounded Tardiness Under EPDF Pfair Multiprocessor Scheduling
The authors consider the scheduling of recurrent (i.e., periodic, sporadic, or rate-based) real-time task systems on multiprocessor platforms consisting of M identical, unit-capacity processors. Pfair scheduling, originally introduced by the research, is the only known way of optimally scheduling such multiprocessor task systems. The Earliest-Pseudo-Deadline-First (EPDF) Pfair algorithm is more efficient than other known Pfair scheduling algorithms, but is not optimal for scheduling recurrent real-time task systems on more than two identical processors. Although not optimal, EPDF may be preferable for real-time systems instantiated on less-powerful platforms, those with soft timing constraints, or those whose task composition can change at run-time.