ATB: Area-Time response Balancing algorithm for scheduling real-time hardware tasks

Abstract

This paper describes a novel scheduling algorithm for the execution of hardware tasks with real-time constraints onto partially and dynamically reconfigurable FPGAs. The AreaTime response Balancing scheduling algorithm (ATB) is inspired by the well-known Earliest Deadline First (EDF) algorithm, which is extended with a technique for reducing the fragmentation on FPGA's reconfigurable area. This technique promotes the reuse of the resources that are released when great area tasks finish their execution by smaller area tasks as long as the real-time constraints permit to do so. Providing an exclusively time-based algorithm, such as EDF, with support for dealing with area-related issues ensures the best results. Simulation results reported in this paper show that ATB misses 23% less deadlines than EDF. Moreover, since FPGA's damaged resources provoke unpredictable fragmentation on the device, ATB is currently the best scheduling option to be used in a Reliable Reconfigurable Real-Time Operating System (R3TOS).

A Roadmap for Autonomous Fault-Tolerant Systems

“…6. The real-time scheduler coordinates access to the ICAP in an efficient way and thus, it assigns the appropriate execution times to the hardware tasks [48]. The allocator is aimed at deciding the best placement for every hardware task selected to be executed.…”