FTI-TMR: A Fault Tolerance and Isolation Algorithm for Interconnected Multicore Systems

Two-Phase TMR conserves energy by partitioning redundancy operations into two stages and making the execution of the third task copy optional, yet it remains susceptible to permanent faults. Reactive TMR (R-TMR) counters this by isolating faulty cores, handling both transient and permanent faults. However, the lightweight hardware required by R-TMR not only increases complexity but also becomes a single point of failure itself. To bypass isolated node constraints, this paper proposes a Fault Tolerance and Isolation TMR (FTI-TMR) algorithm for interconnected multicore systems. We construct a stability metric characterized by its prior and posterior estimates to identify the most reliable nodes in the system. These nodes then perform periodic diagnostics to isolate permanent faults. The experimental results show that FTI-TMR reduces task workload by approximately 30% compared with baseline TMR, while achieving higher permanent-fault coverage.