Method and apparatus for communication in a multi-processor computer system

Abstract

Multiple instances of operating systems execute cooperatively in a single multiprocessor computer wherein all processors and resources are electrically connected together. The single physical machine with multiple physical processors and resources is subdivided by software into multiple partitions, each with the ability to run a distinct copy, or instance, of an operating system. At different times, different operating system instances may be loaded on a given partition. Resources, such as CPUs and memory, can be dynamically assigned to different partitions and used by instances of operating systems running within the machine by modifying the configuration. The partitions themselves can also be changed without rebooting the system by modifying the configuration tree. Inter-instance communication can occur in at least two different ways. In a first communication method, a single bit, which is part of a bitvector in shared memory, is modified by a first instance to indicate to a second instance that a predetermined event associated with that bit has occurred. In a second method, packetized data from the first instance is stored in shared memory, and the first instance notifies the second instance of the presence of the data. The second instance then retrieves the data and acts upon it accordingly.