Method for synchronizing plurality of time of year clocks in partitioned plurality of processors where each partition having a microprocessor configured as a multiprocessor backplane manager

Abstract

The processors of a multiprocessor system are managed, or controlled, by a microprocessors referred to as MBM microprocessors, and the input/output units of the multiprocessor system are managed or controlled by microprocessors contained in PBM units. The MBM units and PBM units communicate with each other through a private local area network. The processors may be arranged into partitions by software, where the processors of a partition may exchange messages with each other, but not with other processors of the multiprocessor system. A virtual time of year clock synchronizes the microprocessors of the MBM and PBM units within a partition to form a “base time”. In the event that the operating system of a partition changes the time within that partition, a “delta time” is computed such that the base time plus the delta time gives the set time. The delta time is stored in a database which is replicated within all MBM and PBM microprocessors. A processor determines its current time by reading a register in which current time is written as partition base time plus partition delta time. An advantage of replicating the delta time of each partition in all MBM units is that all processors are then able to determine the “current time” of any other processor in the multiprocessor computer system, regardless of which partition the processor is in.