GUARD: GUAranteed reliability in dynamically reconfigurable systems

Soft errors are a reliability threat for reconfigurable systems implemented with SRAM-based FPGAs. They can be handled through fault tolerance techniques like scrubbing and modular redundancy. However, selecting these techniques statically at design or compile time tends to be pessimistic and prohibits optimal adaptation to changing soft error rate at runtime. We present the GUARD method which allows for autonomous runtime reliability management in reconfigurable architectures: Based on the error rate observed during runtime, the runtime system dynamically determines whether a computation should be executed by a hardened processor, or whether it should be accelerated by inherently less reliable reconfigurable hardware which can trade-off performance and reliability. GUARD is the first runtime system for reconfigurable architectures that guarantees a target reliability while optimizing the performance. This allows applications to dynamically chose the desired degree of reliability. Compared to related work with statically optimized fault tolerance techniques, GUARD provides up to 68.3% higher performance at the same target reliability.