Summary: JOURNAL OF EMBEDDED COMPUTING, VOL. 1, NO. 3, JUNE 2004 1
Efficient Scheduling of Soft Real­time Applications
on Multiprocessors
Anand Srinivasan, Member, IEEE and James H. Anderson, Member, IEEE
Abstract--- In soft real­time applications, tasks are allowed to
miss their deadlines. Thus, less­costly scheduling algorithms can
be used at the price of occasional violations of timing constraints.
This may be acceptable if reasonable tardiness bounds (i.e.,
bounds on the extent to which deadlines may be missed) can
be guaranteed.
In this paper, we consider soft real­time applications im­
plemented on multiprocessors. Pfair scheduling algorithms are
the only known means of optimally scheduling hard real­time
applications on multiprocessors. For this reason, we consider the
use of such algorithms here. In the design of Pfair scheduling
algorithms, devising schemes to correctly break ties when several
tasks have the same deadline is a critical issue. Such tie­breaking
schemes entail overhead that may be unacceptable or unnecessary
in soft real­time applications. In this paper, we consider the
earliest pseudo­deadline first (EPDF) Pfair algorithm, which

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

Collections: Computer Technologies and Information Sciences