Abstract
The research on real-time software systems has produced algorithms that allow to effectively schedule system resources while guaranteeing the deadlines of the application and to group tasks in a very short number of non-preemptive sets which require much less RAM memory for stack. Unfortunately, up to now the research focus has been on time guarantees rather than the optimization of RAM usage. Furthermore, these techniques do not apply to multiprocessor architectures whichare likely to be widely used in future microcontrollers. This paper presents a fast and simple algorithm for sharing resources in multiprocessor systems, to- gether with an innovative procedure for assigning preemption thresholds to tasks. This allows to guarantee the schedulability of hard real-time task sets while minimizing RAM usage. The experimental part shows the effectiveness of a simulated annealing-based tool that allows to and a near optimal task allocation. When use d in conjunction with our preemption threshold assignment algorithm, our tool further reduces the RAM usage in multiprocessor systems.