Controlled dynamic load balancing for a multiprocessor system

• US 5,115,505 A
• Filed: 06/28/1990
• Issued: 05/19/1992
• Est. Priority Date: 12/22/1986
• Status: Expired due to Term

• Current Assignee: Teradata US, Inc. (Teradata Corporation)
• Original Assignee: AT&T, Inc.
• Inventors: Surratt, Grover T., Bishop, Thomas P., Davis, Mark H., Peterson, James S.
• Primary Examiner(s): Shaw, Gareth D.
• Assistant Examiner(s): KULIK, PAUL V
• Application Number:
  US07/545,679
• Time in Patent Office: 691 Days
• Field of Search: 364/200 MS File, 364/900 MS File
• US Class Current: 718/104
• CPC Class Codes: G06F 9/4881 Scheduling strategies for dispatcher, e.g. round robin, multi-level priority queues
• CPC Class Codes: G06F 9/5044 considering hardware capabilities

Abstract

A method for allowing a system administrator, application programmer, and/or program user to adjust the processor assignment function in a multiprocessor system. The system administrator controls the assignment function by defining certain system variables and flags. The application programmer can adjust the assignment function by causing allocation parameters to be passed in a system call before execution of the assignment function. To adjust the assignment function, the program user executes a system command that inserts similar allocation parameters into the program object code file stored in a file system on the multiprocessor system. The program executing the assignment function is responsive to the system variables and flags as well as the allocation parameters and performs the assignment function as it has been adjusted on a system, program or user level basis.

Claims

1. A method for controlling the allocation of system resources in a multiprocessor system having a plurality of processors and one of said processors storing an object code program in a file and said object code program to be initiated on said multiprocessor system, comprising the steps of:

writing by a requesting one of said processors which is requesting the execution of said object code program a set of processor allocation parameters into said stored object code program in response to a user command executed by a user of said multiprocessor system;

reading said stored object code program by an allocating one of said processors in order to allocate the execution of said object code program;

allocating an executing one of said processors by said allocating one of said processors in response to said processor allocation parameters which define processor resources in the read object code program to execute said read object code program; and

providing by said requesting one of said processors other processor allocation parameters for use by said allocating step in response to a system call.

2. The method of claim 1 further comprises the step of storing by said allocating one of said processors system processor allocation flags and said allocating step further responsive to said stored system processor allocation flags to allocate said executing one of said processors.

3. A method for controlling the allocation of system resources in a multiprocessor system having a plurality of processors and one of said processors storing an object code program in a file and said object code program in a file and said object code program to be initiated on said multiprocessor system, comprising the steps of:

inserting a set of processor allocation parameters into said stored object code program by a requesting one of said processors which is requesting the execution of said object code program;

reading said stored object code program by an allocating one of said processors in order to allocate the execution of said object code program;

allocating an executing one of said processors by said allocating one of said processors in response to said processor allocation parameters which define processor resources in the read object code program to execute said read object code program;

said step of inserting comprises the step of writing a subset of said processor allocation parameters into said stored object code program in response to a user command executed by a user of said multiprocessor system;

storing by said requesting one of said processors a subset of said processor allocation parameters in response to a system call;

storing by said allocating one of said processors system processor allocation flags; and

said allocating step further in response to said stored system processor allocation flags allocates said executing one of said processors.

4. The method of claim 3 wherein said allocating step further comprises the step of:

checking one of said system flags to determine whether a specific processor assignment is allowed;

verifying that a specific processor request which requested said executing one of said processors has been made upon said specific processor assignment being allowed; and

assigning said executing one of said processors upon said specific processor request having been made.

5. The method of claim 4 wherein said allocating step further comprises the steps of:

checking whether a second one of said system flags designates that said requesting one of said processors be assigned to execute said object code program thereby becoming said executing one of said processors; and

assigning said requesting one of said processors to execute said object code program upon said second system flags being set.

6. The method of claim 5 wherein said processors are grouped either as public or private processors and said allocating step comprises the steps of:

maintaining a table to indicate the availability or unavailability of each of said processors;

checking whether a third one of said system flags indicates that only public processors are to be assigned to execute said object code program;

checking to assure that at least one of said public processors are available to execute said object code program; and

making in said table all private processors of said system as unavailable upon said third one of said system flags being set and at least one of said public processors being available.

7. The method of claim 6 wherein said allocating step further comprises the steps of:

checking a fourth one of said system flags indicating that ones of said processor allocation parameters designating the type of processor to be used for assignment are to be examined;

examining a first one of said parameters designating that said requesting one of said processors be given the assignment;

assigning said requesting one of said processors to execute said object code program upon said first one of said parameters being set;

checking a second one of said parameters designating that a specified processor associated with a given file is to be assigned to execute said object code program;

verifying that the processor associated with the specified file is available by examining a third one of said parameters upon said second one of said parameters being set; and

assigning said associated processor to execute said object code program upon the examined third one of said parameters indicating the availability of said associated processor.

8. The method of claim 7 wherein a fourth one of said processor allocation parameters designates processor types allowable for processor assignment and a fifth one of said processor allocation parameters designates processor types disallowed for said processor assignment and a sixth one of said processor allocation parameters designates processors to be included in the allowable processors for said processor assignment and a seventh one of said processor allocation parameters designates processors to be excluded from allowable processors for the processor assignment and said allocating step further comprises the steps of:

marking as unavailable in said table all processors of processor types not designated in said fourth one of said processor allocation parameters;

marking as unavailable in said table all processors of said processor types designated in said fifth one of said processor allocation parameters;

marking as unavailable in said table all processors not designated in said sixth one of said processor allocation parameters; and

marking as unavailable in said table all processors designated in said seventh one of said processor allocation parameters.

9. The method of claim 8 wherein said allocating step further comprises the steps of:

checking a fifth one of said system flags indicating that information concerning processor loading is to be utilized in determining the processor assignment;

determining the loading for each of said processors;

calculating a load value on the basis of the processor with the least load; and

marking as unavailable in said table processors with loading in excess of the calculated value.

10. The method of claim 9 wherein said allocating step further comprises the steps of:

checking a sixth one of said system flags indicating that information concerning whether one of said processors is already executing another occurrence of said object code program;

determining whether any of said processors are executing another occurrence of said object code program upon said sixth one of said system flags being set; and

marking as unavailable in said table all processors that are not executing another occurrence of said object code program upon one of said processors executing another occurrence of said object code program.

11. The method of claim 10 wherein said allocating step further comprises the steps of:

checking a seventh one of said system flags indicating that the amount of free memory of each of said processors is to be utilized in making the processor assignment;

determining the amount of free memory of each of said processors;

determining the processor that has the maximum amount of free memory available;

calculating a lower value of free memory on the basis of the determined maximum amount of free memory; and

marking as unavailable in said table all processors having less than said lower value of free memory.

12. The method of claim 11 wherein said allocating step further comprises the steps of:

checking an eighth one of said system flags indicating whether or not the number of open files related to said object code program on one of said processors is to be utilized in making the processor assignment;

determining the one of said processors with the open files upon said eighth one of said system flags being set;

verifying that said one of said processors with the most open files is available; and

assigning said processor with the most open files to execute said object code program upon said processor with the most open files being marked available in said table.

13. The method of claim 12 wherein said system stores a plurality of system variables and a first one of said system variables contains a maximum limit of the number of processors associated with said object code program and said allocating step comprising the steps of:

checking a ninth one of said system flags indicating that the processor associated with said file storing said object code program is to be utilized for processor assignment;

checking a tenth system flag indicating that the processor requesting execution of said object code program is to be utilized in said processor assignment;

comparing the number of processors associated with said program requesting the execution of said object code program;

assigning said processor associated with said file storing said object code program to execute said program upon said ninth system flag being set and said tenth system flag being set and the number of processors associated with said object code program requesting the execution of said object code program being less than said first one of said system variables and said processor associated with said file storing said object code program being available; and

assigning said requesting one of said processors upon said processor associated with said file being marked unavailable in said table and said ninth system flag being set and said tenth system flag being set and the number of processors associated with said file storing said object code program requesting the execution of said object code program less than said first one of said system variables.

14. The method of claim 13 wherein said allocating step further comprises the step of assigning said requesting processor to execute said object code program upon said tenth system flag being set.

15. The method of claim 14 wherein said allocating step further comprises the step of assigning said processor associated with said file having said object code program to execute said object code program upon said ninth system flag being set.

16. The method of claim 15 wherein said allocating step further comprises the steps of:

determining the available memory of each of the processors marked as available in said table; and

assigning the processor with the greatest amount of available memory that is marked as being available in said table to execute said object code program.