System for indicating and scheduling additional execution time based on determining whether the execution unit has yielded previously within a predetermined period of time

• US 8,024,739 B2
• Filed: 01/09/2007
• Issued: 09/20/2011
• Est. Priority Date: 01/09/2007
• Status: Expired due to Fees

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: Lewis, Russell Lee
• Primary Examiner(s): An; Meng A
• Assistant Examiner(s): Diep; Louis
• Application Number:
  US11/621,495
• Publication Number:
  US 20080168447A1
• Time in Patent Office: 1,715 Days
• Field of Search: 718/104, 718/102, 718/103, 718/107, 718/10
• US Class Current: 718/104
• CPC Class Codes: G06F 9/461 Saving or restoring of program or task context
• CPC Class Codes: G06F 9/485 Task life-cycle, e.g. stopping, restarting, resuming execution G06F9/4881 takes precedence

Abstract

Provided are a method, system, and article of manufacture, wherein an execution unit requests additional execution time from a kernel to prevent the execution unit from being swapped out during an execution of a critical section. The kernel determines whether the execution unit has previously avoided yielding execution to other execution units within a predetermined period of time after being allocated the additional execution time in response to at least one previous request for the additional execution time. The kernel allocates the additional execution time to the execution unit, in response to determining that the execution unit has not previously avoided yielding execution to the other execution units within the predetermined period of time after being allocated the additional execution time in response to the at least one previous request for the additional execution time.

Claims

1. A method, comprising:

requesting, by an execution unit, a first additional execution time from a kernel to prevent the execution unit from being swapped out during an execution of a critical section, wherein the first additional execution time comprises a limited amount of extra time indicated by the execution unit;

determining, by the kernel, whether the execution unit has previously avoided yielding execution to other execution units within a predetermined period of time after being allocated a second additional execution time in response to at least one previous request for the second additional execution time, wherein the second additional execution time is allocated prior to the requesting of the first additional execution time;

allocating, by the kernel, the first additional execution time to the execution unit after providing a temporary increase in a priority of the execution unit, in response to determining that the execution unit has not previously avoided yielding execution to the other execution units within the predetermined period of time after being allocated the second additional execution time in response to the at least one previous request for the second additional execution time;

maintaining a first indicator in the kernel, wherein the first indicator indicates whether the execution unit has previously avoided yielding execution to the other execution units within the predetermined period of time after being allocated the second additional execution time in response to the at least one previous request for the second additional execution time; and

maintaining at least one second indicator that indicates whether the first additional time has been granted by the kernel to the execution unit.

2. The method of claim 1, further comprising:

maintaining a third indicator that indicates whether the first additional time has been requested by the execution unit from the kernel.

3. The method of claim 1, wherein the requesting, by the execution unit, of the first additional execution time from the kernel to prevent the execution unit from being swapped out during an execution of a critical section does not include any indication from the execution unit to increase the any priority for the execution unit.

4. The method of claim 2, wherein the execution unit is a first thread, the method further comprising:

determining, by the kernel, that a second thread that is to be swapped in to replace the first thread is part of the same process as the first thread; and

allocating, by the kernel, the first additional execution time to the first thread in response to determining that the second thread that is to be swapped in to replace the first thread is part of the same process as the first thread whether or not the process has previously avoided yielding execution for other processes within the predetermined period of time.

5. The method of claim 4, wherein the execution unit is one of a process or a thread, wherein the kernel is part of an operating system, and wherein the execution unit is not part of the kernel, and wherein the requesting, the determining, and the allocating are performed via system calls.

6. A system, comprising:

memory; and

processor coupled to the memory, wherein the processor executes operations, the operations comprising;

requesting, by an execution unit, a first additional execution time from a kernel to prevent the execution unit from being swapped out during an execution of a critical section, wherein the first additional execution time comprises a limited amount of extra time indicated by the execution unit;

determining, by the kernel, whether the execution unit has previously avoided yielding execution to other execution units within a predetermined period of time after being allocated a second additional execution time in response to at least one previous request for the second additional execution time, wherein the second additional execution time is allocated prior to the requesting of the first additional execution time;

allocating, by the kernel, the first additional execution time to the execution unit after providing a temporary increase in a priority of the execution unit, in response to determining that the execution unit has not previously avoided yielding execution to the other execution units within the predetermined period of time after being allocated the second additional execution time in response to the at least one previous request for the second additional execution time;

maintaining a first indicator in the kernel, wherein the first indicator indicates whether the execution unit has previously avoided yielding execution to the other execution units within the predetermined period of time after being allocated the second additional execution time in response to the at least one previous request for the second additional execution time; and

maintaining at least one second indicator that indicates whether the first additional time has been granted by the kernel to the execution unit.

7. The system of claim 6, the operations further comprising:

maintaining a third indicator that indicates whether the first additional time has been requested by the execution unit from the kernel.

8. The system of claim 6, wherein the requesting, by the execution unit, of the first additional execution time from the kernel to prevent the execution unit from being swapped out during an execution of a critical section does not include any indication from the execution unit to increase the any priority for the execution unit.

9. The system of claim 7, wherein the execution unit is a first thread, the operations further comprising:

determining, by the kernel, that a second thread that is to be swapped in to replace the first thread is part of the same process as the first thread; and

allocating, by the kernel, the first additional execution time to the first thread in response to determining that the second thread that is to be swapped in to replace the first thread is part of the same process as the first thread whether or not the process has previously avoided yielding execution for other processes within the predetermined period of time.

10. The system of claim 9, wherein the execution unit is one of a process or a thread, wherein the kernel is part of an operating system, and wherein the execution unit is not part of the kernel, and wherein the requesting, the determining, and the allocating are performed via system calls.

11. A computer readable storage, wherein code stored in the computer readable storage when executed by a computer causes operations, the operations comprising:

requesting, by an execution unit, a first additional execution time from a kernel to prevent the execution unit from being swapped out during an execution of a critical section, wherein the first additional execution time comprises a limited amount of extra time indicated by the execution unit;

determining, by the kernel, whether the execution unit has previously avoided yielding execution to other execution units within a predetermined period of time after being allocated a second additional execution time in response to at least one previous request for the second additional execution time, wherein the second additional execution time is allocated prior to the requesting of the first additional execution time;

allocating, by the kernel, the first additional execution time to the execution unit after providing a temporary increase in a priority of the execution unit, in response to determining that the execution unit has not previously avoided yielding execution to the other execution units within the predetermined period of time after being allocated the second additional execution time in response to the at least one previous request for the second additional execution time;

maintaining a first indicator in the kernel, wherein the first indicator indicates whether the execution unit has previously avoided yielding execution to the other execution units within the predetermined period of time after being allocated the second additional execution time in response to the at least one previous request for the second additional execution time; and

maintaining at least one second indicator that indicates whether the first additional time has been granted by the kernel to the execution unit.

12. The computer readable storage of claim 11, the operations further comprising:

maintaining a third indicator that indicates whether the first additional time has been requested by the execution unit from the kernel.

13. The computer readable storage of claim 11, wherein the requesting, by the execution unit, of the first additional execution time from the kernel to prevent the execution unit from being swapped out during an execution of a critical section does not include any indication from the execution unit to increase the any priority for the execution unit.

14. The computer readable storage of claim 12, wherein the execution unit is a first thread, the operations further comprising:

determining, by the kernel, that a second thread that is to be swapped in to replace the first thread is part of the same process as the first thread; and

allocating, by the kernel, the first additional execution time to the first thread in response to determining that the second thread that is to be swapped in to replace the first thread is part of the same process as the first thread whether or not the process has previously avoided yielding execution for other processes within the predetermined period of time.

15. The computer readable storage of claim 14, wherein the execution unit is one of a process or a thread, wherein the kernel is part of an operating system, and wherein the execution unit is not part of the kernel, and wherein the requesting, the determining, and the allocating are performed via system calls.

16. A method for deploying computing infrastructure, comprising integrating computer-readable code into a computer, wherein the code in combination with the computer performs:

requesting, by an execution unit, a first additional execution time from a kernel to prevent the execution unit from being swapped out during an execution of a critical section, wherein the first additional execution time comprises a limited amount of extra time indicated by the execution unit;

determining, by the kernel, whether the execution unit has previously avoided yielding execution to other execution units within a predetermined period of time after being allocated a second additional execution time in response to at least one previous request for the second additional execution time, wherein the second additional execution time is allocated prior to the requesting of the first additional execution time;

allocating, by the kernel, the first additional execution time to the execution unit after providing a temporary increase in a priority of the execution unit, in response to determining that the execution unit has not previously avoided yielding execution to the other execution units within the predetermined period of time after being allocated the second additional execution time in response to the at least one previous request for the second additional execution time;

maintaining a first indicator in the kernel, wherein the first indicator indicates whether the execution unit has previously avoided yielding execution to the other execution units within the predetermined period of time after being allocated the second additional execution time in response to the at least one previous request for the second additional execution time; and

maintaining at least one second indicator that indicates whether the first additional time has been granted by the kernel to the execution unit.

17. The method for deploying computing infrastructure of claim 16, wherein the code in combination with the computer further performs:

maintaining a third indicator that indicates whether the first additional time has been requested by the execution unit from the kernel.

18. The method for deploying computing infrastructure of claim 16, wherein the requesting, by the execution unit, of the first additional execution time from the kernel to prevent the execution unit from being swapped out during an execution of a critical section does not include any indication from the execution unit to increase the any priority for the execution unit.

19. The method for deploying computing infrastructure of claim 17, wherein the execution unit is a first thread, wherein the code in combination with the computer further performs:

determining, by the kernel, that a second thread that is to be swapped in to replace the first thread is part of the same process as the first thread; and

allocating, by the kernel, the first additional execution time to the first thread in response to determining that the second thread that is to be swapped in to replace the first thread is part of the same process as the first thread whether or not the process has previously avoided yielding execution for other processes within the predetermined period of time.

20. The method for deploying computing infrastructure of claim 19, wherein the execution unit is one of a process or a thread, wherein the kernel is part of an operating system, and wherein the execution unit is not part of the kernel, and wherein the requesting, the determining, and the allocating are performed via system calls.