Architecture for a multi-user general-purpose parallel system.

A multi-user general-purpose parallel system can make good use of the available hardware by sharing it among a mix of jobs with complementary requirements. The central task of the operating system in such an environment is to partition the machine dynamically between these jobs. We propose a new control structure to support this task, called distributed hierarchical control, which requires additional control processors to be placed on top of the parallel processors. Thus the processors are effectively organized in a tree structure, where the leaves are user processors and the higher levels are used for operating-system work; note that this structure is orthogonal to the interconnection pattern between the user processors. Operating system algorithms for this structure are outlined.