In multiprocessor systems, many processes may execute the kernel simultaneously. Kernel path synchronization is major challenge in designing multiprocessor operating systems.
Synchronization has a much stronger impact on performance in multiprocessor systems than on uniprocessor systems.
Shared memory architectures with multiple processors have this operating system. The operating system instances on different processors constitute a single parallel program. There are two primary models of multiprocessor-operating systems,: symmetric and asymmetric.
In asymmetric multiprocessor system, each processor is assigned a specific role; there is a designated master processor that control activities of the other subordinates processors.
One of the main reasons for using a multiprocessor system is to provide some effective reliability and graceful degradation in the even of failure.
Multiprocessor operating system