Fujitsu Corporation

Pfu Limited

Hiroaki Ishihata

Takeshi Horie

Toshiyuki Shimizu

Osamu Shiraki

Yoichi Koyanagi

Morio Ikesaka

Yuichiro Ajima

Satoshi Inano

Hirohide Sugahara

Nobutaka Imamura

Akira Kabemoto

Toshiyuki Muta

Takatsugu Sasaki

Junichi Inagaki

Masao Koyabu

Yozo Nakayama

Takayuki Shimamura

Jun Sakurai

Junji Nishioka

Satoshi Shinohara

Naohiro Shibata

Sadayuki Kato

A parallel computing system includes a plurality of processors multi-dimensionally commented by an interconnection network, wherein each of the processors in the parallel computing system determines, in dimensional order, communication channels to other processors in the interconnection network, each of the processors sets, as relative coordinates of destination processors with respect to the plurality of processors in data communications performed at a same timing, relative coordinates common to all of the processors, and each of the processors performs data communications with destination processors having the set relative coordinates.

Parallel computing system and communication control program

A computer system execute summation processing even if the computing sequence is not adhered to in a system for computing a sum of floating point data of a plurality of nodes. Each node sends floating point data to a reduction mechanism, and the reduction mechanism computes the sums only for a group of which exponent sections have a highest value and a group of which exponent sections have a second highest value, and adds the sum of the group of which the exponent sections have a highest value and the sum of the group of which the exponent sections have a second highest value. By this, the consistency of the computation result can be guaranteed even if the sum is computed regardless the computing sequence of the values.

Processing method and computer system for summation of floating point data

A status management unit manages a free status capable of invoking a process switch and a critical status. When a process currently being executed is in an input/output process or in a critical status during a message communication, a switch control means controls a control signal for a process switch, such that a process switch does not take place.

Process switch control apparatus and a process control method

Data transmission control apparatus which controls data transmission between processing systems via a transmission line, each processing system including a memory system consisting of a main memory and a cache memory. The apparatus addresses data in the main memory by a memory address and gives an instruction to transmit the addressed data; determines whether or not the addressed data is in the cache memory; provides a match signal when the data is in the cache memory; reads the addressed data from the cache memory when instructed by the instruction and when a ready signal and the match signal are provided, and, otherwise reads the addressed data from the main memory; writes the data read into a port; transmits the data written in the port to the another processing system connected to the transmission line; and provides the ready signal when the port is ready to receive additional data.

System for a multi-processor system wherein each processor transfers a

An overflow control unit stores, in a FIFO buffer, data generated by a processor. The overflow control unit sets a predetermined flag, upon detecting that a FIFO buffer is full or nearly full. The overflow control unit stores, in a saving buffer, data sent from the processor, while the flag is set. Thereafter, the overflow control unit notifies the processor, by an interrupt, of an effect that an available capacity of the FIFO buffer rises above a predetermined threshold. Upon receiving an interrupt, the processor transfers to the FIFO buffer data saved in the saving buffer. Upon a completion of transferring to the FIFO buffer all data saved in the saving buffer, the processor resets the flag. This allows the overflow control unit to again store in the FIFO buffer, data sent from the processor. The overflow control unit also monitors the volume of data stored in the saving buffer, and notifies the processor, by an interrupt, of an effect that the saving buffer is full. Upon receiving an interrupt, the processor expands an available capacity of the saving buffer.

Queue control apparatus including memory to save data received when

A plurality of processors, each with caches provided for a plurality of processor modules and a local storage in which a main storage is distributed and arranged are mutually connected through an internal snoop bus. The processor modules are mutually connected through a second system bus. By using two separate buses, cache coherence operations within a processor group is kept separate from cache coherence operations outside the processor group.

Coherence apparatus for cache of multiprocessor

In a data gathering/scattering system having a data gathering system and a data scattering system in a parallel computer constituted by a plurality of processors connected in parallel through a common bus or hierarchical common buses, the data gathering/scattering system includes: one processor having a buffer for temporarily storing data gathered from or transmitted to other processors, a three-state buffer for transmitting data from the buffer to the common bus, and a switching unit for switching a connection between a transmission and a reception to form the data gathering system or the data scattering system; each of the other processors having a buffer for temporarily storing data to be transferred or data to be received, a transfer control unit for controlling data transmissions from the buffer to the common bus, a reception control unit for selecting the reception data from among all data on the common bus, a three-state buffer for transmitting data from the buffer to the common bus, and a switching unit for switching a connection between a transmission and a reception to form the data gathering system or the data scattering system, and an AND circuit for obtaining a coincidence of a data transmission or data reception among the processors, and for sending a command for a data transmission or data reception to other processors.

Data gathering/scattering system for a plurality of processors in a

A method for message communications between multiple processor elements in a parallel computer according to this invention comprises the steps of: directly writing a message body containing message information of a message from a transmitting processor element into a shared memory area in a memory of a receiving processor element by a remote writing unit; transmitting a header containing identifier information and pointer information for the message from the transmitting processor element to a message receiving unit of the receiving processor element; and writing the header into a local memory area in the memory in the order of arrival of the headers by the message receiving unit of the receiving processor element.

Message communications system in a parallel computer

A receiving buffer control system comprises a memory having a buffer area serving as a receiving buffer, data being applied to the memory via a bus, a write pointer indicating a write address of the buffer area, and a read pointer indicating a read address of the buffer area. An overrun/underrun detection circuit detects a situation in which an overrun or an underrun will occur in the buffer area in response to the write address indicated by the write pointer and the read address indicated by the read pointer. A control part disables the data from being written into and read out from the buffer area when the overrun/underrun detection circuit detects the situation.

Control system for a ring buffer which prevents overrunning and

When the processor writes a command data string into an address of the command entry area, a corresponding command is created by a bus interface. If an address output by the processor corresponds to a distributed shared memory area, the bus interface creates a remote access command. The send controller constructs a message based on the command created by the bus interface. This message is sent either to an interconnection network, or to a receive controller. The receive controller receives the message and interprets it. An address output by the processor is detected by a cache area access unit, and the cache area in the memory is accessed. When the processor receives an interrupt request while waiting for a response message to a remote read request, an deadlock control unit detects an abnormal end of the remote read request that the remote read has ended in an error, and, controls the processor to process the interrupt request with priority.

Control system for access between processing elements in a parallel

A message receiving method communicates a message among a plurality of computers in a parallel computer system, shortens a delay time in storing a received message in a user area of a memory, and realizes overlap between receipt of a message and execution by a processor. Each computer in the parallel computer system comprises a message buffer for temporarily storing the received message and a message handler for receiving a receive-a-message request from a processor of a computer to which it belongs. If the receive-a-message request arrives before the arrival of the message, the message handler directly transmits the received message to a user area specified by the receive-a-message request. During the transmission period, the message handler prevents the processor from accessing a portion in the user area to which the message has not been transmitted yet.

Message receiving system for use in parallel computer system

An inter-processor synchronization control system in a distributed memory type parallel computer comprises a unit for detecting an establishment of the synchronization of all PEs, a status request register unit provided for each PE for independently issuing a status request through a status request signal, a unit for determining the issues of requests from status request registers of all PEs, a unit for distributing the determination to all PEs and a status detecting register for detecting the status according to the distributed determination and the output of the synchronization establishment detection unit. The inter-processor synchronous control system detects the status of all PEs when the synchronization is established in all PEs.

Synchronization control system in a parallel computer

A communication control system controls communication between parallel computers using a wormhole routing. The system comprises units for connecting a plurality of computer nodes by relay channels within a network to continuously transfer a message divided into a plurality of minimum data units for transmission. Storing units are provided in respective nodes for storing the minimum data units, the number of storing units corresponding to the number of relay channels from the originating node to the most remote node plus 1. Therefore, a deadlock in a communication is avoided, and a high speed communication can be realized.

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Kawasaki, Japan

Hiroaki Ishihata