Unisys Corporation

Peter C Wilson

John A Miller

Penny L Svenkeson

Philip J Erickson

Brett W Tucker

Doug E Morrissey

An inventive protocol for communicating between a management processor and host processors allows for the cooperative management of resources among host processors within a partition and also among a set of partitions in a computer system, wherein each partition may function under an instantiation of an operating system with a group of host processors. The protocol employs a message passing system using mailbox pairs in fixed but moveable or relocatable locations within the computer system shared memory. The messages share a format having specific codes or descriptors that act as codes for coordination of message interpretation. These codes include at least a validity flag and a sequence enumerator, and in a response message of a request/response message pair, a status indicator. Additionally, routing codes and function codes and code modifiers may be provided. Specific implementation details and messages are described to enable the smooth functioning of complex multiprocessor systems.

Communications between partitioned host processors and management processor

A method and apparatus is disclosed for initiating execution of selected application processors in a clustered multiprocessor system without disrupting the addressing mode of the processors. In one embodiment, this is accomplished by initializing the processors in a conventional way, setting the addressing mode, and then leaving each of the processors in an active mode spinning on a designated Startup Address Location. To start an application processor, the OS simply write a target processor ID and a desired start-up address into the Startup Address Location. The application processor with the matching processor ID reads the Startup Address Location, jumps to the address specified in the Start-Up Address code section, and begins execution at that location. In another embodiment, a processor is provided that does not switch addressing modes when switched from a halt state.

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Shoreview, MN, United States of America

Peter C Wilson