Distributed-memory multiprocessor system utilizing plural multiprocessors with virtual storage space

• US 6,665,700 B1
• Filed: 01/04/1996
• Issued: 12/16/2003
• Est. Priority Date: 01/28/1993
• Status: Expired due to Fees

• Current Assignee: Fujitsu Limited
• Original Assignee: Fujitsu Limited
• Inventors: Takayama, Katsunori, Sugisaki, Yoshinori
• Primary Examiner(s): Donaghue, Larry D.
• Application Number:
  US08/582,662
• Time in Patent Office: 2,903 Days
• Field of Search: 711/147, 711/148, 711/206, 711/151, 711/152, 712/38, 710/240, 710/241, 710/242, 709/109
• US Class Current: 718/104
• CPC Class Codes: G06F 12/0815 Cache consistency protocols
• CPC Class Codes: G06F 15/16 Combinations of two or more digital computers each having at least an arithmetic unit, a program unit and a register, e.g. for a simultaneous processing of several programs coordinating program control therefor G06F9/52; in regulating and control system G05B
• CPC Class Codes: G06F 2212/1021 Hit rate improvement

Abstract

In a distributed-memory multiprocessor system in which a plurality of processors have their respective memories, some of the processors are placed in redundant execution of writing into a virtual storage space. At redundant execution, each processor makes a determination of whether or not it is to perform the writing. As a consequence, only a single processor is allowed to write data into the virtual storage space, which solves the data transfer overhead problem. If a processor that has a memory with an area to be written into performs the writing, then the speed of processing will be further increased.

Claims

1. A distributed-memory multiprocessor system, including a plurality of individual processors, wherein each individual processor of said plurality of individual processors includes a memory, and wherein each individual processor is interconnected to other individual processors by a communications line, and wherein the memories of each of the individual processors include a private storage space and a shared storage space, access areas being distributed to shared storage spaces of the plurality of individual processors, said shared storage spaces being configured to form a virtual storage space, said plurality of individual processors being configured to perform parallel processing while accessing said virtual storage space, an individual processor of said plurality of processors comprising:

a right-of-access determination unit making a determination of whether or not the individual processor is to make access to the virtual storage space, said right-of-access determination unit being configured to make said determination when two or more processors of said plurality of processors are in redundant execution of access to said virtual storage space; and

an access unit, coupled to said right-of-access determination unit, making access to said virtual storage space when receiving from said right-of-access determination unit a result of the determination that the individual processor is to make access to the virtual storage space, wherein said right-of-access determination unit determines that the individual processor is to make access to the virtual storage space, and wherein a right-of-access determination unit of another individual processor of said plurality of processors determines that the another processor is not to make access.

2. A distributed-memory multiprocessor system, including a plurality of individual processors, wherein each individual processor of said plurality of individual processors includes a memory, and wherein said each individual processor is interconnected to other individual processors of said plurality of individual processors by a communications line, and wherein the memories of each of the individual processors include a private storage space and a shared storage space, access areas being distributed to shared storage spaces of the plurality of individual processors, said shared storage spaces being configured to form a virtual storage space, said plurality of individual processors being configured to perform parallel processing while making access to the virtual storage space, an individual processor of said plurality of processors comprising:

a right-of-write determination unit making a determination of whether or not said individual processor is to write into the virtual storage space; and

a writing unit, coupled to said right-of-write determination unit, writing the data into said virtual storage space when receiving from said right-of-access determination unit a result of the determination that said individual processor is to write into the virtual storage space, wherein said writing unit prevents writing of the data into said virtual storage space when receiving from said right-of-write determination unit a result of the determination that said individual processor is not to perform the writing into the virtual storage space, wherein said right-of-write determination unit determines that the individual processor is to perform the writing, and a right-of-write determination unit of another processor of said plurality of processors determines that said another processor is not to perform the writing.

3. A distributed-memory multiprocessor system, including a plurality of individual processors, wherein each individual processor of said plurality of individual processors includes a memory, and wherein said each individual processor is interconnected to other individual processors of said plurality of individual processors by a communications line, and wherein the memories of each of the individual processors include a private storage space and a shared storage space, access areas being distributed to shared storage spaces of the plurality of individual processors, said shared storage spaces being configured to form a virtual storage space, said plurality of individual processors being configured to perform parallel processing while making access to the virtual storage space, an individual processor of said plurality of processors comprising:

a right-of-write determination unit making a determination of whether or not said individual processor is to write into the virtual storage space; and

a writing unit, coupled to said right-of-write determination unit, writing the data into said virtual storage space when receiving from said right-of-access determination unit a result of the determination that said individual processor is to write into the virtual storage space, wherein said right-of-write determination unit includes a representative determination unit making a representative determination of whether said individual processor is a representative of two or more processors in redundant execution.

4. The distributed-memory multiprocessor system according to claim 3, wherein said writing unit prevents writing of the data into the virtual storage space when receiving from said representative determination unit a result of the determination that said individual processor is not the representative of two or more processors in redundant execution.

5. The distributed-memory multiprocessor system according to claim 4, wherein said representative determination unit of said individual processor determines that said individual processor is the representative, and a representative determination unit of another processor of the two or more processors determines that said another processor is not the representative.

6. A distributed-memory multiprocessor system, including a plurality of individual processors, wherein each individual processor of said plurality of individual processors includes a memory, and wherein said each individual processor is interconnected to other individual processors of said plurality of individual processors by a communications line, and wherein the memories of each of the individual processors include a private storage space and a shared storage space, access areas being distributed to shared storage spaces of the plurality of individual processors, said shared storage spaces being configured to form a virtual storage space, said plurality of individual processors being configured to perform parallel processing while making access to the virtual storage space, an individual processor of said plurality of processors comprising:

a right-of-write determination unit making a determination of whether or not said individual processor is to write into the virtual storage space; and

a writing unit, coupled to said right-of-write determination unit, writing the data into said virtual storage space when receiving from said right-of-access determination unit a result of the determination that said individual processor is to write into the virtual storage space, wherein said right-of-write determination unit of said individual processor includes a location determination unit making a location determination of whether an area into which said data is written is located within the memory of said individual processor, and wherein said writing unit of said individual processor writes said data into said area when receiving from said location determination unit a result of the determination that said area is located within the memory of said individual processor.

7. The distributed-memory multiprocessor system according to claim 6, wherein said writing unit prevents writing of the data into said virtual storage space when receiving from said location determination unit a result of the determination that the virtual storage space is not located within the memory of said individual processor.

8. A distributed-memory multiprocessor system, including a plurality of individual processors, wherein each individual processor of said plurality of individual processors includes a memory, and wherein said each individual processor is interconnected to other individual processors of said plurality of individual processors by a communications line, and wherein the memories of each of the individual processors include a private storage space and a shared storage space, access areas being distributed to shared storage spaces of the plurality of individual processors, said shared storage spaces being configured to form a virtual storage space, said plurality of individual processors being configured to perform parallel processing while making access to the virtual storage space, an individual processor of said plurality of processors comprising:

a right-of-write determination unit making a determination of whether or not said individual processor is to write into the virtual storage space; and

a writing unit, coupled to said right-of-write determination unit, writing the data into said virtual storage space when receiving from said right-of-access determination unit a result of the determination that said individual processor is to write into the virtual storage space, wherein said individual processor includes the data in the memory thereof, and wherein said right-of-write determination unit includes a representative determination unit making a representative determination of whether or not said individual processor is a representative of two or more of processors in redundant execution, said right-of-write determination unit also including a location determination unit making a location determination of whether an area into which the data is written is located within the memory of said individual processor, and wherein said writing unit copies the data into said area when receiving from said representative determination unit a result of the determination that said individual processor is the representative, and from said location determination unit a result of the determination that said area is located within the memory of said individual processor, and wherein said writing unit transfers the data over said communications line to another individual processor of said two or more processors in redundant execution, in which said area is located, when receiving from the representative determination unit a result of the determination that said individual processor is the representative, and from the location determination unit a result of the determination that said area is not located within the memory of said individual processor, and wherein said writing unit prevents writing of the data into said area when receiving from said representative determination unit a result of the determination that said individual processor is not the representative.

9. The distributed-memory multiprocessor system according to claim 8, wherein said area into which the data is written consists of a plurality of sections distributed to a plurality of memories corresponding to said virtual storage space, and wherein said writing unit writes the data into a section of said area located within the memory of the individual processor and transfers the data to a section of said area located within the memory of at least one other individual processor of said two or more processors in redundant execution over said communications line when writing the data into said area.

10. The distributed-memory multiprocessor system according to claim 8, wherein after said right-of-write determination unit and said writing unit perform a right-of-write determination and a writing respectively, synchronization is performed among said two or more processors to terminate the redundant execution.

11. A distributed-memory multiprocessor system, including a plurality of individual processors, wherein each individual processor of said plurality of individual processors includes a memory, and wherein said each individual processor is interconnected to other individual processors of said plurality of individual processors by a communications line, and wherein the memories of each of the individual processors include a private storage space and a shared storage space, access areas being distributed to shared storage spaces of the plurality of individual processors, said shared storage spaces being configured to form a virtual storage space, said plurality of individual processors being configured to perform parallel processing while making access to the virtual storage space, an individual processor of said plurality of processors comprising:

a right-of-write determination unit making a determination of whether or not said individual processor is to write into the virtual storage space; and

a writing unit, coupled to said right-of-write determination unit, writing the data into said virtual storage space when receiving from said right-of-access determination unit a result of the determination that said individual processor is to write into the virtual storage space, wherein said individual processor includes the data in the memory thereof, and wherein said right-of-write determination unit includes a representative determination unit making a representative determination of whether or not said individual processor is a representative of the two or more processors in redundant execution, said right-of-write determination unit also including a location determination unit making a location determination of whether or not an area into which the data is written is located within memories of the two or more processors in redundant execution, and wherein said writing unit copies the data into said area when receiving from said location determination unit a result of the determination that said area is located within the memories of the two or more processors in redundant execution and that said area is located within the memory of said individual processor, and wherein said writing unit prevents writing of the data into said area when receiving from said location determination unit a result of the determination that said area is located within the memories of the two or more processors but not within the memory of said individual processor, and wherein said writing unit transfers the data over said communications line to another individual processor of said two or more processors, in which said area is located, when receiving from said representative determination unit a result of the determination that said individual processor is the representative and from said location determination unit that said area is not located within the memories of the two or more processors, and wherein said writing unit prevents writing of said data into said area when receiving from said location determination unit a result of the determination that said area is not located within the memories of the two or more processors and from said representative determination unit a result of the determination that said individual processor is not the representative.

12. The distributed-memory multiprocessor system according to claim 11, wherein said area into which the data is written consists of a plurality of sections distributed to a plurality of memories corresponding to said virtual storage space, and wherein said writing unit writes the data into a section of said area located within the memory of said individual processor and transfers the data to a section of said area located within the memory of at least one other individual processor of said two or more processors over said communications line when writing the data into said area.

13. The distributed-memory multiprocessor system according to claim 11, wherein after right-of-write determination of said right-of-write determination unit and writing of said writing unit is completed, synchronization is performed among said two or more processors to terminate the redundant execution.

14. A distributed-memory multiprocessor system having a plurality of individual processors, wherein each individual processor of said plurality of individual processors includes a memory, and wherein the memory of each of said individual processors is associated with a virtual storage space, wherein each individual processor is configured to access said virtual storage space, and wherein at least two individual processors of said plurality of individual processors are configured to write into said virtual storage space during a redundant execution, and wherein said at least two individual processors perform identical processes during the redundant execution, said distributed-memory multiprocessor system comprising:

a representative determination unit making a determination of whether or not an individual processor of said at least two individual processors is representative of said at least two individual processors in redundant execution; and

a writing processing unit, responsive to said representative determination unit, causing said individual processor to write into said virtual storage space at the redundant execution when the representative determination unit determines that the individual processor is the representative, said writing processing unit preventing other processors of said at least two individual processors from writing.

15. A distributed-memory multiprocessor system having a plurality of individual processors, wherein each individual processor of said plurality of individual processors includes a memory, and wherein the memory of each of said individual processors is associated with a virtual storage space, wherein each individual processor is configured to access said virtual storage space, and wherein at least two individual processors of said plurality of individual processors are configured to write into said virtual storage space during a redundant execution, and wherein said at least two individual processors perform identical processes during the redundant execution, each individual processor of said at least two individual processors comprising:

a variable location determination unit making a determination of whether a variable location to be written into is located within the memories of the at least two individual processors in redundant execution, and whether the variable location is within a memory of an individual processor of said at least two individual processors in redundant execution; and

a writing processing unit responsive to said variable location determination unit, causing said individual processor to write into said virtual storage space at redundant execution when said variable location determination unit determines that said variable location is within the memory of said individual processor, said writing processing unit preventing other processors of said at least two individual processors from writing.

16. A distributed-memory processing method performed by a plurality of individual processors, each individual processor of said plurality of individual processors including a memory, each of said plurality of individual processors being interconnected by a communications line, memories of each individual processor of said plurality of individual processors being associated with a virtual storage space, said plurality of individual processors performing parallel processing while accessing said virtual storage space, said method comprising:

determining whether an individual processor of said plurality of individual processors is to write data into said virtual storage space in a process performed by said individual processor, said determination being made when two or more individual processors of said plurality of individual processors are in redundant execution;

writing said data into said virtual storage space when said individual processor is determined to write;

determining whether or not said individual processor is a representative of the two or more individual processors in redundant execution;

determining whether or not an area into which said data is written is present within the memory of said individual processor;

performing one operation, said one operation being one of copying said data into said area when said individual processor is the representative and said area is present within the memory of said individual processor, transferring said data over said communications line to another individual processor of said plurality of individual processors in which said area is present when said individual processor is the representative and said area is not located within the memory of said individual processor; and

preventing said individual processor from writing said data into said area when said individual processor is not the representative.

17. A distributed-memory processing method performed by a plurality of individual processors, each individual processor of said plurality of individual processors including a memory, each of said plurality of individual processors being interconnected by a communications line, memories of each individual processor of said plurality of individual processors being associated with a virtual storage space, said plurality of individual processors performing parallel processing while accessing said virtual storage space, said method comprising:

determining whether an individual processor of said plurality of individual processors is to write data into said virtual storage space in a process performed by said individual processor, said determination being made when two or more individual processors of said plurality of individual processors are in redundant execution;

writing said data into said virtual storage space when said individual processor is determined to write;

determining whether or not said individual processor is a representative of the two or more individual processors in redundant execution;

determining whether or not an area into which said data is written is present within the memories of the two or more individual processors in redundant execution;

determining whether or not said area is present in the memory of said individual processor;

copying said data into said area when said area is present within the memories of the two or more individual processors in redundant execution and said area is present within the memory of said individual processor;

preventing said individual processor from writing said data into said area when said area is present within the memories of the two or more individual processors in redundant execution but not present within the memory of said individual processor;

transferring said data over said communications line to another individual processor of said plurality of individual processors in which said area is present when said area is not present within the memories of the two or more individual processors in redundant execution and said individual processor is the representative; and

preventing said individual processor from writing said data into said area when said area is not present within the memories of the two or more individual processors in redundant execution and said individual processor is not the representative.