Optimization of performance degradation after reconfiguration of fault tolerant multiprocessor systems

Many of fault tolerant multiprocessor systems possess reconfiguration features. Each process has its copy(ies) allocated on some other processor element(s). After a processor element fault occurred and was detected, a reconfiguration kernel performs a reconfiguration. Each process that has been running on the faulty processor element is rebuilt and restarted on some other processor element, using its copy. The reconfiguration kernel has to determine which processor element is the most suitable for process rebuilding and restarting. Then it moves the process code, rebuilds and restarts the process. In this paper we present an approach to finding a processor assignment scheme for processes from a faulty processor that was designed with regard to the lowest performance degradation after reconfiguration. The approach is based on the Colored Petri Net ( CPN) model of a part of a reconfigurable multiprocessor system. Simulations of the model have shown that it is possible to assign a processor element suitable for process rebuilding and restarting using some process and processor parameters. It is possible to find an assignment that is optimal or close to optimal.