Restricting preemption points presents a viable way to address the problem of preemption delay. The mechanism of preemption deferral was first proposed by Burns et al. [8]. It has a number of advantages as has been pointed out in several works e.g. [9], [10]. In particular, Gang Yao et al. provide a comparison of all the available methods described so far in literature [10] regarding restricted preemptive scheduling using fixed task priority.