Resource Reservation for Mixed Criticality Systems
Giuseppe Lipari, Giorgio Buttazzo · 2013
This paper presents a reservation-based approach to sched- ule mixed criticality systems in a way that guarantees the schedulability of high-criticality tasks independently of the behaviour of low-criticality tasks. Two key ideas are presented: first, to reduce the system uncer- tainty and advance the time at which a high-criticality task reveals its actual execution time, the initial portion of its code is handled by a ded- icated server with a bandwidth reserved for the worst-case, but with a shorter deadline; second, to avoid the pessimism related to off-line budget allocation, an efficient reclaiming mechanism, namely the GRUB algo- rithm (6), is used to exploit the budget left by high-criticality tasks in favor of those low-criticality tasks that can still complete within their deadline.