Work-in-Progress: Tight Response-Time Analysis for Periodic Preemptive Tasks Under Global Scheduling
Pourya Gohari, Jeroen P. M. Voeten, Mitra Nasri · 2023
While multicore real-time systems are extensively employed in the industry, research gaps still exist in developing a scalable analysis to find tight bounds on the worst-case response time (WCRT) of tasks scheduled by global preemptive scheduling policies. Additionally, the presence of release jitter poses a challenge where examining the earliest and latest release times may not derive WCRT. The existing analyses either provide very conservative bounds or face challenges in scaling to systems with numerous cores and tasks. This work provides preliminary foundations to derive tight WCRT bounds for tasks scheduled by global preemptive job-level fixed-priority scheduling policies (e.g., EDF and FP) on homogeneous multicore platforms by performing a reachability analysis using time-label-transition systems. Our solution uses 2 orders of magnitude less memory than UPPAAL and identifies on average 12% (up to 39%) more schedulable task sets than sufficient schedulability analyses (e.g., for systems with 4 cores and 10 tasks).