Forced idle of a data processing system

• US 8,225,121 B2
• Filed: 05/20/2011
• Issued: 07/17/2012
• Est. Priority Date: 01/07/2008
• Status: Active Grant

• Current Assignee: Apple Inc.
• Original Assignee: Apple Inc.
• Inventors: Sotomayor, Guy G. Jr., Cox, Keith, Conroy, David G., Culbert, Michael
• Primary Examiner(s): KNOLL, CLIFFORD H
• Application Number:
  US13/112,634
• Publication Number:
  US 20110219247A1
• Time in Patent Office: 424 Days
• Field of Search: 713300-324, 323/234
• US Class Current: 713/323
• CPC Class Codes: G06F 1/3203 Power management, i.e. event-based initiation of a power-saving mode
• CPC Class Codes: G06F 1/324 by lowering clock frequency
• CPC Class Codes: G06F 1/3296 by lowering the supply or operating voltage
• CPC Class Codes: G06F 11/3423 where the assessed time is active or idle time
• CPC Class Codes: Y02D 10/00 Energy efficient computing, e.g. low power processors, power management or thermal management
• CPC Class Codes: Y02D 30/50 in wire-line communication networks, e.g. low power modes or reduced link rate

Abstract

Exemplary embodiments of methods and apparatuses to manage a power of a data processing system are described. One or more constraint parameters of a system are monitored. The data processing system is forced into an idle state for a first portion of a time while allowed to operate for a second portion of the time based on the one or more constraint parameters, wherein the system is forced into the idle state in response to comparing a target idle time to an actual idle time. The target idle time of the system is determined, in one embodiment, based on the one or more constraint parameters. The actual idle time of the system may be monitored to take into account interrupts which disrupt an idle time and idle times resulting from no software instructions to execute. The system may be allowed to operate based on comparisons of the target idle time and the actual idle time.

Claims

1. A machine-implemented method, comprising:

monitoring one or more constraint parameters of a system;

determining a target idle time based at least in part on the one or more constraint parameters;

determining an actual idle time;

comparing the target idle time with the actual idle time; and

forcing the system into an idle state based on the comparing.

2. The machine-implemented method of claim 1, further comprising

measuring the actual idle time;

storing the measured actual idle time, and

determining the actual idle time that is accumulated over one or more time intervals based on the stored actual idle time.

3. The machine-implemented method of claim 1, wherein the system is forced into the idle state if the actual idle time is less than the target idle time.

4. The machine-implemented method of claim 1, further comprising

allowing the system to avoid the idle state if the actual idle time is greater than the target idle time.

5. The machine-implemented method of claim 1, wherein in the idle state the system is prevented from executing the instructions.

6. The machine-implemented method of claim 1, further comprising

determining an idle ratio based on the one or more constraint parameters;

and

determining an idle rate based on the idle ratio.

7. The machine-implemented method of claim 6, wherein the determining the idle rate comprises

maintaining the idle rate if the idle ratio is smaller than a predetermined threshold;

and

increasing the idle rate if the idle ratio is greater than the predetermined threshold.

8. The machine-implemented method of claim 1, further comprising

receiving an interrupt, and

updating the actual idle time based on the interrupt.

9. A non-transitory machine-readable storage medium storing executable program instructions which cause a data processing system to perform operations, comprising:

monitoring one or more constraint parameters of a system;

determining a target idle time based at least in part on the one or more constraint parameters;

determining an actual idle time;

comparing the target idle time with the actual idle time; and

forcing the system into an idle state based on the comparing.

10. The non-transitory machine-readable medium of claim 9, further including instructions that cause the data processing system to perform operations comprising

measuring the actual idle time;

storing the measured actual idle time, and

determining the actual idle time that is accumulated over one or more time intervals based on the stored actual idle time.

11. The non-transitory machine-readable medium of claim 9, wherein the system is forced into the idle state if the actual idle time is less than the target idle time.

12. The non-transitory machine-readable medium of claim 9, further including instructions that cause the data processing system to perform operations comprising

allowing the system to avoid the idle state if the actual idle time is greater than the target idle time.

13. The non-transitory machine-readable medium of claim 9, wherein in the idle state the system is prevented from executing the instructions.

14. The non-transitory machine-readable medium of claim 9, further including instructions that cause the data processing system to perform operations comprising

determining an idle ratio based on the one or more constraint parameters;

and

determining an idle rate based on the idle ratio.

15. The non-transitory machine-readable medium of claim 14, wherein the determining the idle rate comprises

maintaining the idle rate if the idle ratio is smaller than a predetermined threshold;

and

increasing the idle rate if the idle ratio is greater than the predetermined threshold.

16. The non-transitory machine-readable medium of claim 9, further including instructions that cause the data processing system to perform operations comprising receiving an interrupt, and updating the actual idle time based on the interrupt.

17. A data processing system, comprising:

a memory; and

a processor coupled to the memory, wherein the processor is configured to monitor one or more constraint parameters of a system, the processor is configured to determine a target idle time based at least in part on the one or more constraint parameters, the processor is configured to determine an actual idle time, the processor is configured to compare the target idle time with the actual idle time; and

the processor is configured to force the system into an idle state based on the comparing.

18. The data processing system of claim 17, wherein the processor is further configured to measure the actual idle time, the processor is further configured to store the measured actual idle time in the memory, and wherein the processor is further configured to determine the actual idle time that is accumulated over one or more time intervals based on the stored actual idle time.

19. The data processing system of claim 17, wherein the system is forced into the idle state if the actual idle time is less than the target idle time.

20. The data processing system of claim 17, wherein the processor is further configured to allow the system to avoid the idle state if the actual idle time is greater than the target idle time.

21. The data processing system of claim 17, wherein in the idle state the system is prevented from executing the instructions.

22. The data processing system of claim 17, wherein the processor is further configured to determine an idle ratio based on the one or more constraint parameters;

and

wherein the processor is further configured to determine an idle rate based on the idle ratio.

23. The data processing system of claim 22, wherein the processor is further configured to maintain the idle rate if the idle ratio is smaller than a predetermined threshold;

and to increase the idle rate if the idle ratio is greater than the predetermined threshold.

24. The data processing system of claim 17, wherein the processor is further configured to receive an interrupt, and to update the actual idle time based on the interrupt.

25. A data processing system, comprising:

means for monitoring one or more constraint parameters of a system;

means for determining a target idle time based at least in part on the one or more constraint parameters;

means for determining an actual idle time;

means for comparing the target idle time with the actual idle time; and

means for forcing the system into an idle state based on the comparing.