Summary: A Hierarchical Multiprocessor Bandwidth Reservation
Scheme with Timing Guarantees #
Hennadiy Leontyev
James H. Anderson
Department of Computer Science, The University of North Carolina at Chapel Hill
Abstract
A multiprocessor scheduling scheme is presented for supporting hierarchical containers that
encapsulate sporadic soft and hard real­time tasks. In this scheme, each container is allocated a
specified bandwidth, which it uses to schedule its children (some of which may also be contain­
ers). This scheme is novel in that, with only soft real­time tasks, no utilization loss is incurred
when provisioning containers, even in arbitrarily deep hierarchies. Presented experiments show
that the proposed scheme performs well compared to conventional real­time scheduling tech­
niques that do not provide container isolation.
1 Introduction
In the Linux community, two recent developments have occurred that are of relevance to real­
time software design processes. The first is the introduction of ``real­time'' features such as high­
resolution timers, priority inheritance, and shortened non­preemptable sections in mainline Linux
(in versions 2.6.16 to 2.6.22). The second is the introduction (in version 2.6.24) of mechanisms for
supporting container hierarchies (LVS, 2007; Eriksson and Palmroos, 2007; Lessard, 2003). Con­
tainers are an abstraction that allows different task groups to be isolated from one another (mainly, by

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

Collections: Computer Technologies and Information Sciences