Method for executing communication between processors in parallel computer

• US 5,761,426 A
• Filed: 08/21/1996
• Issued: 06/02/1998
• Est. Priority Date: 08/24/1995
• Status: Expired due to Term

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: Komatsu, Hideaki, Ogasawara, Takeshi, Ishizaki, Kazuaki
• Primary Examiner(s): Pan, Daniel H.
• Application Number:
  US08/700,898
• Time in Patent Office: 650 Days
• Field of Search: 360/137, 360/69, 395/309, 395/200.56, 395/200.51, 395/707, 395/709, 395/200.61, 395/800.22, 395/653, 395/500, 395/77, 395/800.29, 395/730, 395/183.19, 370/422, 370/397, 370/255, 364/DIG. 1, 364/DIG. 2, 371/20.1, 340/949, 369/29, 379/93.14, 379/75, 379/84
• US Class Current: 709/221
• CPC Class Codes: G06F 15/17 using an input/output type connection, e.g. channel, I/O port

Abstract

A method for communication between processors in a parallel computer, particularly a method in which a past communication history is used to omit the calculation of the communication pattern between processors, whereby the communication between processors is carried out at high speed. The method performs a communication between processors in a computer having a plurality of processors by the steps of: (a) extracting a plurality of parameters for deciding the communication pattern between processors, (b) preparing a working area for storing the parameters, (c) generating an object code for storing the parameters in the working area, (d) storing the parameters in the working area to memorize a history of the communication pattern or a history of a memory access pattern for performing the reading/writing of data for the communication between processors, (e) comparing the parameters based on the execution of the object code with the parameters stored in the working area when the object code is executed, and (f) executing the communication between processors by reusing the communication pattern or the memory access pattern in response to the result of the comparison.

Claims

1. A method for executing communication between processors in a computer having a plurality of processors, said method comprising the steps of:

(a) extracting a plurality of parameters for deciding a communication pattern between processors;

(b) preparing a working area for storing said parameters;

(c) generating an object code for storing said parameters in said working area;

(d) storing said parameters in said working area, said parameters stored in said working area memorizing at least one of a history of a communication pattern and a history of a memory access pattern for performing data writing and reading for the communication between processors;

(e) comparing said extracted parameters based on the execution of said object code with said parameters stored in said working area when said object code is executed; and

(f) executing the communication between processors by reusing said communication pattern or said memory access pattern in response to the result of the comparison.

2. A method as set forth in claim 1 wherein the extraction of said parameters in said step (a) includes checking whether the value changes during the execution of a constant or a nested loop, and determining whether said communication pattern can be cached.

3. A method as set forth in claim 2 wherein said parameters extracted in said step (a) includes extracting:

a parameter related to a loop in a program, the number of processors onto which the arrays on the left and right parts in an assignment statement in the loop, the magnitude of each dimension of the arrays, the method for distributing each dimension of the arrays, and parameters in the expression for determining the reference of the arrays.

4. A method as set forth in claim 1 wherein said step (e) includes making a comparison to determine whether patterns of said extracted parameters based on the execution of said object code is identical with the related communication pattern of said parameters stored in said working area.

5. A method as set forth in claim 1 wherein said step (e) includes making a comparison to determine whether patterns of said extracted parameters based on the execution of said object code is identical with the related communications pattern of said parameters stored in said working area, and if identical, makes a further comparison to determine whether patterns of said extracted parameters are identical with the related memory access pattern of said parameters stored in said working area.

6. A method as set forth in claim 1 wherein said parameters extracted in said step (a) includes extracting:

a parameter related to a loop in a program, the number of processors onto which the arrays on the left and right parts in an assignment statement in the loop, the magnitude of each dimension of the arrays, the method for distributing each dimension of the arrays, and parameters in the expression for determining the reference of the arrays.

7. A method as set forth in claim 1 wherein said communication pattern includes describing an area for communicating data between one processor and another processor.

8. A method as set forth in claim 1 wherein said memory access pattern includes describing a memory area managed by one processor when data is communicated according to said communication pattern.

9. A method as set forth in claim 1 wherein said step (f) includes using said parameters stored in said working area.