1. A method for performing operations in a multiprocessing system comprising a plurality of processor cores, said method comprising: dynamically configuring a selective pairing facility to communicate with at least two processor cores for performing one of: independent parallel operation or highly-reliable fault tolerant operations; scheduling, by a scheduler device operatively connected with said selective pairing facility, software-resilient threads to said at least two processor cores when the selective pairing facility is configured for said independent operation of said at least two cores; scheduling, by said scheduler device, hardware-resilient threads to said at least two processor cores connected to said selective pairing facility when the selective pairing facility is configured for said highly-reliable fault tolerant operations, said selective pairing facility providing simultaneous pairwise execution of a thread at paired first and second two processor cores; and, checking execution results generated by said paired first and a second processor cores in order to detect incorrect execution sequences.