Hewlett-packard Development Company, L.p.

Other

David Golden

David W Hartwell

Darrel D Donaldson

Samuel Hammond Duncan

David T Mayo

Dennis Mazur

William H Freeman

Glenn A Herdeg

Richard Edward Bracken

The invention is a control system using microprocessors which communicate through a Local Area Network (private LAN) to control operation of both processors and input and output subsystems (IO system) of a multiprocessor computer system. The processors each have memory associated therewith, and each processor has an IO system comprising a plurality of busses such as PCI busses, associated therewith. The processors are cabled together in a mesh arrangement so that messages can be transferred between any of the processors and delivered to memory associated with the destination processor, or delivered to an IO system associated with the destination processor, etc. The microprocessors are powered on when power is applied to the chassis of the multiprocessor system, and the microprocessors then control the processors of the multiprocessor system, including applying power to the processors, forming hard partitions containing selected processors, computing routes from a processor to a memory associated with any processor for read and write transactions, computing routes to IO subsystems associated with any processor of the hard partition, forming partition boundaries so that processors in one hard partition cannot read and write to memory or IO systems associated with processors in another hard partition, forming soft partitions of processors, controlling boot-up of operating systems executing on the processors of the multiprocessor computer system, removing power from a failed processor, providing power to a repaired processor, etc.

Partition formation using microprocessors in a multiprocessor computer system

An anti-starvation interrupt protocol for use in avoiding livelock in a multiprocessor computer system is provided. At least one processor is configured to include first and second control status registers (CSRs). The first CSR buffers information, such as interrupts, received by the processor, while the second CSR keeps track of the priority level of the interrupts. When an interrupt controller receives an interrupt, it issues a write transaction to the first CSR at the processor. If the first CSR has room to accept the write transaction, the processor returns an acknowledgement, whereas if the first CSR is already full, the processor returns a no acknowledgment. In response to a no acknowledgment, the interrupt controller increments an interrupt starvation counter, and checks to see whether the counter exceeds a threshold. If not, the interrupt controller waits a preset time and reposts the write transaction. If it does, the interrupt controller issues a write transaction having a higher priority to the second CSR. In response, the processor copies all of the pending interrupts from the first CSR into the memory subsystem, thereby freeing up the first CSR to accept additional write transactions.

Anti-starvation interrupt protocol

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 &ldquo;base time&rdquo;. In the event that the operating system of a partition changes the time within that partition, a &ldquo;delta time&rdquo; 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 &ldquo;current time&rdquo; of any other processor in the multiprocessor computer system, regardless of which partition the processor is in.

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

A control system using microprocessors for communicating through a LAN to control operation of processors and input and output subsystems (IO system) of a multi-processor computer system. Each processor includes memory, and an IO system comprising a plurality of busses. The processors are cabled together in a mesh arrangement so that messages can be transferred between any of the processors and delivered to memory associated with the destination processor, or an IO system associated with the destination processor, etc. The processors and IO system are mounted in a rack, and an IO system is associated with each processor. A rack may be hot swapped. In hot swapping, the microprocessor control system computes new routing tables for messages through the new cabling arrangement. Microprocessors, IO devices, and processor boards may be hot swapped.

Online control of a multiprocessor computer system

An automated backplane cable connection system (and method) for manually connecting a cluster of processor modules to other modules or I/O boxes uses a programmed server management control console which identifies connection terminals provided on the processors/I/O boxes and controls LEDs which are associated with the connection terminals, on a one to one basis. The programmed server management console uses diagnostic circuitry and causes LEDs corresponding to connection terminals engaged by a newly made cable connection to initially light up, and enables them to turn off if the newly made cable connection is proper as verified by the diagnostic circuitry. The cluster of processor modules may be connected to a plurality of I/O boxes through an Ethernet LAN. The processor modules or I/O boxes may have sufficient nonvolatile memory to remember backplane cable connections which have already been made according to user needs, as initially guided by the programmed server management control console. From the memory, replacement of cables when necessary, is facilitated, without the need for assistance by the server management console. If connection changes are needed because of design modifications or additions, the server management control console would again be needed. If a newly made backplane connection is improper or is broken, the diagnostic circuitry will enable the corresponding LEDs to stay lit or to start flashing (depending in the design), thereby signaling need for intervention. Backplane cable connections may be made by semiskilled personnel by using this invention. Also, &ldquo;hot-add, hot-replace, hot-swap&rdquo; of connection is easily possible by this invention without interrupting continuity of operation of the system.

Automated backplane cable connection identification system and method

A stencil apparatus includes a plurality of letters, wherein each letter includes vacuum porting to effect secure mounting to an underlying surface. A modification of the invention includes a matrix of letters mounted to a single panel to permit simultaneous mounting of the panel to an underlying surface.

Vacuum stencil apparatus

A system whereby intensity of illumination of vehicle brake lights is increased responsively to relatively increased force applied on the vehicle brake pedal. A transducer installed in the pressurized brake fluid line produces an output signal proportionate to the braking force; which signal is utilized by circuitry to control the illumination of the brake lights to communicate to following drivers not only the fact that the brakes are being applied, but also the relative force of application for indicating the degree of travel arrest.

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Woonsocket, RI, United States of America

David Golden