System and method for conserving power

• US 7,797,563 B1
• Filed: 06/09/2006
• Issued: 09/14/2010
• Est. Priority Date: 06/09/2006
• Status: Active Grant

• Current Assignee: Sun Microsystems Incorporated (Oracle Corporation), Sun Microsystems Technology Ltd. (Oracle Corporation)
• Original Assignee: Oracle America, Inc. (Oracle Corporation)
• Inventors: Moll, Laurent R., Rowlands, Joseph
• Primary Examiner(s): CHEN, TSE W
• Application Number:
  US11/450,103
• Time in Patent Office: 1,558 Days
• Field of Search: 713/320, 713/324
• US Class Current: 713/324
• CPC Class Codes: G06F 1/3203 Power management, i.e. event-based initiation of a power-saving mode
• CPC Class Codes: G06F 1/3243 Power saving in microcontroller unit
• CPC Class Codes: Y02D 10/00 Energy efficient computing, e.g. low power processors, power management or thermal management

Abstract

A system includes a plurality of processors and a monitor coupled to each of the plurality of processors. The monitor is located in a location separate from the plurality of processors. At least some portions of one or more of the plurality of processors enter a power-conservation mode after the one or more of the plurality of processors request one or more resources. The system further includes a power-management controller. The power-management controller is operative to cause the at least some portions of the one or more of the plurality of processors to enter the power-conservation mode after the one or more of the plurality of processors request the one or more resources.

Claims

1. A system comprising:

a plurality of processors;

a power-management controller; and

a monitor coupled to and located in a location separate from each of the plurality of processors,

wherein, when one or more of the plurality of processors send a request to the monitor for one or more resources, the monitor and the power-management controller acquire ownership of the one or more resources and the power-management controller causes at least some portions of the one or more of the plurality of processors to enter a power-conservation mode, and

wherein, when the one or more resources become available to the one or more of the plurality of processors, the monitor and the power-management controller relinquish ownership of the one or more resources and the power-management controller causes the at least some portions of the one or more of the plurality of processors to exit the power-conservation mode.

2. The system of claim 1, wherein the monitor utilizes logic that is operative to access one or more of memory traffic, coherent memory traffic, and coherency traffic.

3. The system of claim 1, wherein all portions of the one or more of the plurality of processors enter the power-conservation mode.

4. The system of claim 1, wherein the one or more resources comprise one or more addresses.

5. The system of claim 4, wherein the monitor is operative to monitor whether a write operation to the one or more addresses has been performed.

6. A method for conserving power, the method comprising:

providing a plurality of processors, a power-management controller, and a monitor coupled to and located in a location separate from each of the plurality of processors;

causing the monitor and the power-management controller to acquire ownership of one or more resources when one or more of the plurality of processors send a request to the monitor for the one or more resources;

causing at least some portions of the one of more of the plurality of processors to enter a power conservation mode after the monitor and the power-management controller acquire ownership of the one or more resources;

causing the monitor and the power-management controller to relinquish ownership of the one or more resources when the monitor detects that the one or more resources have become available to the one or more of the plurality of processors; and

causing the at least some portions of the one or more of the plurality of processors to exit the power-conservation mode after the monitor and the power-management controller relinquish ownership of the one or more resources.

7. The method of claim 6, wherein the one or more resources comprise one or more addresses, and wherein the method further comprises:

transmitting the one or more addresses to the monitor; and

setting the monitor.

8. The method of claim 6, wherein the monitor utilizes logic that is operative to access one or more of memory traffic, coherent memory traffic, and coherency traffic.

9. The method of claim 6, wherein all portions of the one or more of the plurality of processors enter the power-conservation mode.

10. The method of claim 6, further comprising monitoring whether a write operation to the one or more addresses has been performed.

11. A computer-readable medium comprising program instructions for causing a computer system to execute a method comprising:

providing a plurality of processors, a power-management controller, and a monitor coupled to and located in a location separate from each of the plurality of processors;

causing the monitor and the power-management controller to acquire ownership of one or more resources when one or more of the plurality of processors send a request to the monitor for the one or more resources;

causing at least some portions of the one or more of the plurality of processors to enter a power conservation mode after the monitor and the power-management controller acquire ownership of the one or more resources;

causing the monitor and the power-management controller to relinquish ownership of the one or more resources when the monitor detects that the one or more resources have become available to the one or more of the plurality of processors; and

causing the at least some portions of the one or more of the plurality of processors to exit the power-conservation mode after the monitor and the power-management controller relinquish ownership of the one or more resources.

12. The computer-readable medium of claim 11, wherein the one or more resources comprise one or more addresses, and wherein the method further comprises:

transmitting the one or more resources to the monitor; and

setting the monitor.

13. The computer-readable medium of claim 11, wherein the monitor utilizes logic that is operative to access one or more of memory traffic, coherent memory traffic, and coherency traffic.

14. The computer-readable medium of claim 11, further comprising program instructions for monitoring whether a write operation to the one or more addresses has been performed.