This section describes the Mach interface to processor sets and individual processors. The interface allows to group processors into sets and control the processors and processor sets.
A processor is not a central part of the interface. It is mostly of relevance as a part of a processor set. Threads are always assigned to processor sets, and all processors in a set are equally involved in executing all threads assigned to that set.
The processor set is represented by two ports, a name port processor_set_name used to query information about the host accessible to everyone, and a control port processor_set used to manipulate it.