Architecture of Master-slave multiprocessor: Below given is the architecture of Master-slave multiprocessor. Here, the fist CPU acts as a master CPU and it runs the operating system. This is the only CPU in the architecture which runs the operating system. A system call must always have to be redirected to the master CPU. The other CPUs runs the user processes and are known as slaves. Master-slave architecture works fine for about 10 slave CPUs, hence the maximum value of n can be 10.
Architecture of Symmetric multiprocessor: In this type of architecture the operating system resides in the memory. Any CPU in the symmetric multiprocessor architecture can access the operating system from the memory. To avoid the problem of two CPUs accessing the operating system at the same time, a mutex is used. A CPU which needs to access the operating system first has to acquire the mutex.