FORCED IDLE OF A DATA PROCESSING SYSTEM

• US 20090177907A1
• Filed: 01/07/2008
• Published: 07/09/2009
• Est. Priority Date: 01/07/2008
• Status: Active Grant

• Current Assignee: Apple Inc.
• Original Assignee: Apple Inc.
• Inventors: Conroy, David G., Culbert, Michael, Cox, Keith, Sotomayor, Guy G. JR.
• Granted Patent: US 7,949,889 B2
• Time in Patent Office: Days
• US Class Current: 713/340
• 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; and

forcing the system into an idle state for a first portion of a time while allowing the system to continue to operate for a second portion of the time based on the one or more constraint parameters, wherein the forcing is performed in response to comparing a target idle time to an actual idle time.

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

determining the target idle time of the system based on one or more system constraint parameters;

monitoring the actual idle time, and wherein the actual idle time is accumulated over a period of time.

3. The machine-implemented method of claim 1, wherein the idle state prevents the system from executing instructions and wherein a decision to avoid an idle time is made if the actual idle time is greater than the target idle time when the decision is made.

4. The machine-implemented method of claim 1, wherein the actual idle time and the target idle time are based on a common period of time.

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

receiving an interrupt; and

switching from the idle state to an operating state in response to the interrupt.

6. The machine-implemented method of claim 5, wherein the monitoring takes interrupts into account when determining the actual idle time.

7. A data processing system, comprising:

a processor;

a memory coupled to the processor;

one or more sensors coupled to the processor to monitor one or more constraint parameters of the system, wherein the processor is configured to force the system into an idle state for a first portion of a time while allowing the system to operate for a second portion of the time based on the one or more constraint parameters, wherein the processor is configured to force the system into the idle state in response to comparing a target idle time to an actual idle time.

8. The data processing system of claim 7, wherein the processor is further configured to determine the target idle time of the system based on one or more system constraint parameters, to monitor the actual idle time, and wherein the actual idle time is accumulated over a period of time.

9. The data processing system of claim 7, wherein the actual idle time and the target idle time are based on a common period of time.

10. The data processing system of claim 7, wherein the processor is further configured to receive an interrupt, and to switch from the idle state to an operating state in response to the interrupt.

11. The data processing system of claim 7, wherein the memory stores one or more look up tables that include the target idle time associated with the one or more constraint parameters.

12. The data processing system of claim 7, wherein the idle state prevents the system from executing instructions and wherein a decision to avoid an idle time is made if the actual idle time is greater than the target idle time when the decision is made.

13. A 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; and

forcing the system into an idle state for a first portion of a time while allowing the system to operate for a second portion of the time based on the one or more constraint parameters, wherein the forcing is performed in response to comparing a target idle time to an actual idle time.

14. The machine-readable medium of claim 13, further including instructions that cause the data processing system to perform operations comprising:

determining the target idle time of the system based on one or more system constraint parameters;

monitoring the actual idle time; and

wherein the actual idle time is accumulated over a period of time.

15. The machine-readable medium of claim 13, wherein the idle state prevents the system from executing instructions, and wherein a decision to avoid an idle time is made if the actual idle time is greater than the target idle time when the decision is made.

16. The machine-readable medium of claim 13, wherein the actual idle time and the target idle time are based on a common period of time.

17. The machine-readable medium of claim 13, further including instructions that cause the data processing system to perform operations comprising:

receiving an interrupt; and

switching from the idle state to an operating state in response to the interrupt.

18. The machine-readable medium of claim 13, wherein the monitoring takes interrupts into account when determining the actual idle time.

19. A data processing system, comprising:

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

means for forcing the system into an idle state for a first portion of a time while allowing the system to operate for a second portion of the time based on the one or more constraint parameters, wherein the forcing is performed in response to comparing a target idle time to an actual idle time.

20. The data processing system of claim 19, further comprising:

means for determining the target idle time of the system based on one or more system constraint parameters;

means for monitoring the actual idle time; and

wherein the actual idle time is accumulated over a period of time.

21. The data processing system of claim 19, wherein the idle state prevents the system from executing instructions, and wherein a decision to avoid an idle time is made if the actual idle time is greater than the target idle time when the decision is made.

22. The data processing system of claim 19, wherein the actual idle time and the target idle time are based on a common period of time.

23. The data processing system of claim 19, further comprising:

means for receiving an interrupt; and

means for switching from the idle state to an operating state in response to the interrupt.

24. The data processing system of claim 23, wherein the means for monitoring takes interrupts into account when determining the actual idle time.

25. The data processing system of claim 20 further comprising:

means for storing one or more look up tables that include the target idle time associated with one or more constraint parameters.