Method and apparatus for managing power in computer systems

• US 7,519,838 B1
• Filed: 09/03/2004
• Issued: 04/14/2009
• Est. Priority Date: 10/26/2000
• Status: Expired due to Term

• Current Assignee: Apple Inc.
• Original Assignee: Apple Inc.
• Inventors: Suurballe, David
• Primary Examiner(s): CONNOLLY, MARK A
• Application Number:
  US10/934,075
• Time in Patent Office: 1,684 Days
• Field of Search: 713/300, 713/320, 713/324
• US Class Current: 713/300
• CPC Class Codes: G06F 1/26 Power supply means, e.g. regulation thereof for memories G11C
• CPC Class Codes: G06F 1/3203 Power management, i.e. event-based initiation of a power-saving mode
• CPC Class Codes: G06F 1/3209 Monitoring remote activity, e.g. over telephone lines or network connections
• CPC Class Codes: G06F 1/3287 by switching off individual functional units in the computer system
• CPC Class Codes: Y02D 10/00 Energy efficient computing, e.g. low power processors, power management or thermal management

Abstract

The invention is directed towards minimizing power consumption in computer systems. One embodiment of the invention is a power management system that is used for a computer system that has at least one device and one power domain. This embodiment uses two different power managers to manage the power consumption of the device and the power domain. Specifically, this embodiment has (1) a first power manager that determines when to change power state of the device, and (2) a second power manager that determines when to change power state of the power domain. Each of these power managers decides to change the power state of its corresponding device or domain based on information from several different sources. These sources can include power-management clients and power managers of related domains or devices.

Claims

1. A method for distributing management of power of a computer system, the method comprising:

a) receiving at a parent power manager, a specified lower input power requirement from a child power manager; and

b) defining a power state for a parent power domain of the parent power manager based on said received input power requirement, said child power manager being a power manager for a member of said parent power domain.

2. The method of claim 1 further comprising:

a) notifying a grandparent power manager of said defined power state;

b) receiving from said grandparent power manager a notification of a change in said power state of said parent power domain to said defined power state; and

c) changing said power state of said parent power domain to said defined power state upon receiving said notification of said change in said power state.

3. The method of claim 2 further comprising notifying said child power manager of said change in said power state of said parent power domain.

4. The method of claim 3 further comprising changing a power state of at least one device associated with said child power manager.

5. The method of claim 3 further comprising changing a power state of at least one power domain associated with said child power manager.

6. The method of claim 1 further comprising notifying said child power manager, wherein notifying said child power manager allows said child power manager to change a power state of at least one device associated with said child power manager.

7. The method of claim 1 further comprising notifying said child power manager, wherein notifying said child power manager allows said child power manager to change a power state of at least one power domain associated with said child power manager.

8. The method of claim 1 further comprising changing a child power state to said specified lower input power requirement, wherein defining said power state of said parent power domain comprises changing said power state of said parent power domain to a lower power state based on at least said specified lower input power requirement from said child power manager.

9. The method of claim 1, wherein said input power requirement from said child power manager is based on an activity state of a device associated with said child power manager.

10. The method of claim 1, wherein after receiving the input power requirement from the child power manager, the method further comprises identifying the input power requirement of a set of child power managers.

11. The method of claim 10, wherein defining the power state of the parent power domain is further based on the identified input power requirement of the set of child power managers.

12. The method of claim 1, wherein the member of the power domain comprises at least one device, at least one power domain, or at least one device and one power domain.

13. A method for distributing management of power of a computer system, the method comprising:

a) at a parent power manager, defining a power state of a parent power domain based on an output power characteristic of said parent power domain;

b) changing said power state of the parent power domain to said defined power characteristic of said parent power domain; and

c) after the changing, notifying a child power manager with data related to said changed parent power state, said child power manager being a power manager for a member of said parent power domain, said child power manager for determining a power state of the member based on the data related to the changed parent power state.

14. The method of claim 13, further comprising receiving an acknowledgement from said child power manager that said defined parent power state will be tolerated, wherein defining said power state of said parent power domain further comprises changing said power state to said defined power state in response to receiving said acknowledgement from said child power manager.

15. The method of claim 14 further comprising changing the power state of the member associated with said child power manager.

16. The method of claim 14 further comprising changing a power state of a power domain associated with said child power manager.

17. The method of claim 14 further comprising notifying a grandparent power manager of said change in said power state of said parent power domain.

18. The method of claim 13 further comprising changing the power state of the member associated with said child power manager based on said change in said power state of said parent power domain.

19. The method of claim 13 further comprising changing a power state of a power domain associated with said child power manager based on said change in said power state of said parent power domain.

20. The method of claim 13, wherein the member of the power domain comprises at least one device, at least one power domain, or at least one device and one power domain.

21. A computer readable medium storing a computer program, the computer program comprising sets of instructions for:

a) receiving at a parent power manager, a specified lower input power requirement from a child power manager; and

b) defining a power state for a parent power domain of the parent power manager based on said received input power requirement, said child power manager being the power manager for a member of said parent power domain.

22. A computer readable medium storing a computer program, the computer program comprising sets of instructions for:

a) at a parent power manager, defining a power state of a parent power domain based on an output power characteristic of said parent power domain;

b) changing said power state of the parent power domain to said defined power characteristic of said parent power domain; and

c) after the changing, notifying a child power manager with data related to said changed parent power state, said child power manager being a power manager for a member of said parent power domain, said child power manager for determining a power state of the member based on the data related to the changed parent power state.

23. A system comprising:

a power domain and a member of the power domain;

a first power manager and a second power manager;

the second power manger for notifying the first power manager of a specified lower input power requirement, the second power manager being the power manager for the member of the power domain; and

the first power manager for defining a power state of the power domain based on said input power requirement.

24. The system of claim 23, wherein the system is a computer system.

25. The system of claim 23, wherein the system is a power management system.

26. The system of claim 23, wherein the member of the power domain comprises at least one device, at least one power domain, or at least one device and one power domain.

27. A system comprising:

a power domain and a member of the power domain;

a first power manager and a second power manager;

the first power manager for defining and changing a power state of the power domain based on an output power characteristic of the power domain; and

the second power manager for receiving a notification of said defined power state after said first power manager changes said power state, said second power manager being the power manager for a member of said power domain and for determining a power state of the member based on the data related to the changed parent power state.

28. The system of claim 27, wherein the system is a computer system.

29. The system of claim 27, wherein the system is a power management system.

30. The system of claim 27, wherein the member of the power domain comprises at least one device, at least one power domain, or at least one device and one power domain.

31. A system comprising:

a first power management member;

a second power management member that derives power from the first power management member;

a first power manager for (i) computing a power state of the first power management member, and (ii) changing the power state of the first power management member based on the computed power state for the first power management member; and

a second power manager for (i) computing a power state of the second power management member, and (ii) changing the power state of the second power management member based on the computed power state for the second power management member when the power state of the first power management member is sufficient to satisfy the change to the power state of the second power management member.

32. The system of claim 31, wherein the first power manager computes the power state of the first power management member based on information that the second power manager supplies to the first power manager, wherein the computation by the first power manager is used by the first power manager to control the power of the first power management member.

33. The system of claim 31 further comprising a first power-controlling driver for receiving instructions from the first power manager to control the power state of the first power management member.

34. The system of claim 33, wherein the instructions to the first power-controlling driver cause the first power-controlling driver to change the power state of the first power management member.

35. The system of claim 31 further comprising a third power management member, wherein the first power manager and the second power manager directly control a power state of the third power management member.

36. The system of claim 31 further comprising a third power management member, wherein the second power manager controls a power state of the third member, wherein the first power manager computes the power state of the first power management member based on power requirement information for the second and third power management members that the second power manager supplies to the first power manager.

37. The system of claim 31, wherein the power management members comprise at least one device or at least one power domain.

38. The system of claim 37, wherein the first power management member comprises a plurality of members, wherein the first power manager computes the power state for a particular power management member in the plurality of members by identifying available output power from at least one parent power manager and a power requirement from at least one member of the plurality of power management members.

39. The system of claim 37, wherein a power domain supplies power to at least one power management member.

40. The system of claim 37, wherein the first power management member is a first power domain, said first power domain comprising a plurality of power management members.

41. The system of claim 40, wherein the first power manager computes the power state for the first power domain based on information that the first power manager receives from the power management members of the first power domain and the second power manager.

42. The system of claim 31, wherein the system is a computer system.

43. The system of claim 31, wherein the system is a power management system.

44. A system comprising:

for each of a plurality of devices, a device power manager for controlling a power state of the device;

for each of a plurality of power domains, a power domain power manager for controlling a power state of the power domain by defining the power state based on an input power requirement received from a device power manager when an output power characteristic of the power domain power manager is insufficient to satisfy the input power requirement, wherein said power domains and devices have a hierarchical relationship,

wherein the device power managers and the power domain power managers communicate with each other based on a hierarchical relationship that is similar to the hierarchical relationship of the devices and power domains.

45. The system of claim 44, wherein the devices and power domains communicate with each other based on the hierarchical relationship of the devices and power domains.

46. The system of claim 44, wherein the power domain power manager determines whether the output power characteristic of the power domain power manager is sufficient to satisfy the input power requirement.

47. A method comprising:

at a first power manager, computing a power state of a first power management member;

changing the power state of the first power management member based on the computed power state by the first power manager;

at a second power manager, computing a power state of a second power management member, wherein the second power management member derives power from the first power management member; and

changing the power state of the second power management member based on the computed power state by the second power manager when the power state at the first power management member is sufficient to satisfy the change to the power state of the second power management member.

48. The method of claim 47, wherein computing the power state of the first or second power management member is based on information that one power manager supplies to the other power manager, wherein the computations of each particular power manager are used to control the power of the particular power manager'"'"'s power management member.

49. The method of claim 47 further comprising computing the power state of the first power management member based on information that the first power manager receives from a power management client.

50. The method of claim 47 further comprising receiving at a first power-controlling driver, instructions from the first power manager to control the power state of the first power management member.

51. The method of claim 50, wherein the instructions to the first power-controlling driver cause the first power-controlling driver to change the power state of the first power management member.

52. The method of claim 47, wherein the power management members comprise at least one device or at least one power domain.

53. The method of claim 52, wherein a power domain supplies power to at least one power management member.

54. The method of claim 52, wherein the first power management member is a first power domain, the method further comprising supplying at a second power domain, power to the first power domain and computing a power state of the second power domain at a third power manager, wherein the second power manager computes a power state of the first power domain based on information that the second power manager receives from the third power manager.

55. The method of claim 52, wherein the first power management member is a first power domain, said first power domain comprising a plurality of power management members.

56. The method of claim 55, wherein the first power manager computes the power state for the first power domain based on information that the first power manager receives from the power management members of the first power domain and the second power manager.