Multi-core system, vehicle electronic control unit and task switching method

Disclosed is a multi-core system (100) for allocating a task generated from a program (AP11) of a control system to a CPU core (1-n) so as to perform it. The system is provided with a testing instructing means (33) making a second CPU core (2) test the task at the time of switching the task that the first CPU core (1) performs to the second CPU core (2) so as to perform it, a judging means (36) judging whether an execution result of the first CPU core (1) matches with that of the second CPU core or not and an allocation deciding means (38) deciding an allocation destination of the task to the second CPU core (2) when the execution result of the first CPU core (1) is matched with that of the second CPU core (2).