Weight Bound Limits in Supertasking Approach for Guaranteed Timeline Constraints

Abstract

We investigated the problem of supertasking in Pfair-scheduled multi-processor systems. In this approach, a set of tasks (component tasks) is grouped together to form a supertask, which is then scheduled as an ordinary Pfair task. Whenever a supertask is scheduled, its processor time is allocated to its component tasks according to an internal scheduling algorithm. Supertasking approach does not provide guarantees that its component tasks will respect the timeline constraints. In this paper, we propose a new condition for constructing a supertask from its component tasks in such a way that all timing constraints of its component tasks are guaranteed without compromising on schedulability loss. This condition is expressed as weight bound relation b/w supertask and its component tasks.