In cases, where a detailed memory system simulation is not important (for example, initialization and testing phases), the macro MEMSYS_OFF can be used to speed up the simulation. This macro turns off the multiprocessor and memory system simulation and instead assume a perfect cache hit rate. This macro can be useful for initialization and cleanup phases; the macro MEMSYS_ON is used to restart full memory system simulation. Note that each processor must independently invoke MEMSYS_OFF and MEMSYS_ON; the decision of whether or not to simulate the full memory system is made on a processor-by-processor basis.