Methods and apparatuses for load balancing between multiple processing units

• US 8,284,205 B2
• Filed: 10/24/2007
• Issued: 10/09/2012
• Est. Priority Date: 10/24/2007
• Status: Active Grant

• Current Assignee: Apple Inc.
• Original Assignee: Apple Inc.
• Inventors: Miller, Howard, Brunner, Ralph
• Primary Examiner(s): Crawford, Jacinta M
• Application Number:
  US11/923,463
• Publication Number:
  US 20090109230A1
• Time in Patent Office: 1,812 Days
• Field of Search: 345/501, 345/502, 345/503, 345/504, 345/505
• US Class Current: 345/502
• CPC Class Codes: G06F 1/3203 Power management, i.e. event-based initiation of a power-saving mode
• CPC Class Codes: G06F 1/329 by task scheduling
• CPC Class Codes: G06F 15/16 Combinations of two or more digital computers each having at least an arithmetic unit, a program unit and a register, e.g. for a simultaneous processing of several programs coordinating program control therefor G06F9/52; in regulating and control system G05B
• CPC Class Codes: G06F 2209/501 Performance criteria
• CPC Class Codes: G06F 9/5044 considering hardware capabilities
• CPC Class Codes: G06F 9/5094 where the allocation takes into account power or heat criteria power management in computers in general G06F1/3203; thermal management in computers in general G06F1/206
• CPC Class Codes: Y02D 10/00 Energy efficient computing, e.g. low power processors, power management or thermal management

Abstract

Exemplary embodiments of methods and apparatuses to dynamically redistribute computational processes in a system that includes a plurality of processing units are described. The power consumption, the performance, and the power/performance value are determined for various computational processes between a plurality of subsystems where each of the subsystems is capable of performing the computational processes. The computational processes are exemplarily graphics rendering process, image processing process, signal processing process, Bayer decoding process, or video decoding process, which can be performed by a central processing unit, a graphics processing units or a digital signal processing unit. In one embodiment, the distribution of computational processes between capable subsystems is based on a power setting, a performance setting, a dynamic setting or a value setting.

Claims

1. A machine implemented method comprising:

selecting a performance or power consumption setting of a system, the system including a plurality of processing units;

determining values associated with the setting for each processing unit to perform a task, wherein the values are based upon one of

a power consumption value for each processing unit to perform the task corresponding to a low power setting,

a performance value for each processing unit to perform the task corresponding to a high performance setting, and

a performance and power consumption ratio for each processing unit to perform the task corresponding to a cost-effective setting; and

redistributing the task between the plurality of processing units based upon the determined values associated with the setting for each processing unit to perform the task.

2. The method as in claim 1, wherein the redistributing is done dynamically while the system is running and wherein the processing units comprise a central processing unit (CPU) and a special processing unit, and

wherein the task is created from one of a plurality of different software pipelines.

3. The method as in claim 2, wherein the special processing unit is a graphics processing unit (GPU) and wherein the GPU performs a plurality of graphics processing operations when the high performance setting is selected and the CPU performs the plurality of graphics processing operations when the low power setting is selected.

4. The method as in claim 2, wherein the special processing unit is a GPU and wherein the GPU performs a plurality of graphics processing operations when the low power setting is selected and the CPU performs the plurality of graphics processing operations when the high performance setting is selected.

5. The method as in claim 1, wherein the task is at least one of a graphics rendering process, an image processing process, a signal processing process, a Bayer filtering process, a video decoding process, or any combination thereof.

6. The method as in claim 1, wherein the setting is selected from a group that includes

a dynamic mode wherein the processing units are automatically chosen to prevent power or thermal overload based on a threshold.

7. The method as in claim 1, wherein the determination of values associated with the setting for each processing unit to perform the task includes determining the power consumption value, performance value, or performance and power consumption ratio for each processing unit to perform the task under a plurality of loads.

8. A system, comprising:

a memory; and

a plurality of processing units coupled to the memory through at least one bus, wherein one of the processing units is configured to

determine values associated with the setting for each processing unit to perform a task, wherein the values are based upon one of

a power consumption value for each processing unit to perform the task corresponding to a low power setting,

a performance value for each processing unit to perform the task corresponding to a high performance setting, and

a performance and power consumption ratio for each processing unit to perform the task corresponding to a cost-effective setting; and

redistribute the task between the plurality of processing units based upon the determined values associated with the setting for each processing unit to perform the task.

9. The system as in claim 8, wherein the processing task is redistributed dynamically while the system is running and wherein the processing units comprise a central processing unit (CPU) and a special processing unit, and

wherein the task is created from one of a plurality of different software pipelines.

10. The system as in claim 9, wherein the special processing unit is a graphics processing unit (GPU) and wherein the GPU performs a plurality of graphics processing operations when the high performance setting is selected and the CPU performs the plurality of graphics processing operations when the low power setting is selected.

11. The system as in claim 9, wherein the special processing unit is a GPU and wherein the GPU performs a plurality of graphics processing operations when the low power setting is selected and the CPU performs the plurality of graphics processing operations when the high performance setting is selected.

12. The system as in claim 8, wherein the task is at least one of a graphics rendering process, a image processing process, a signal processing process, a Bayer filtering process, a video decoding process, or any combination thereof.

13. The system as in claim 8, wherein the setting is selected from a group that includes

a dynamic mode wherein the processing units are automatically chosen to prevent power or thermal overload based on a threshold.

14. The system as in claim 8, wherein the determination of values associated with the setting for each processing unit to perform the task includes determining the power consumption value, performance value, or performance and power consumption ratio for each processing unit to perform the task under a plurality of loads.

15. An article of manufacturing comprising:

a non-transitory machine-accessible storage medium storing data that, when accessed by a machine, cause the machine to perform operations comprising;

selecting a performance or power consumption setting of a system, the system including a plurality of processing units;

determining values associated with the setting for each processing unit to perform a task, wherein the values are based upon one of

a power consumption value for each processing unit to perform the task corresponding to a low power setting,

a performance value for each processing unit to perform the task corresponding to a high performance setting, and

a performance and power consumption ratio for each processing unit to perform the task corresponding to a cost-effective setting; and

redistributing the task between the plurality of processing units based upon the determined values associated with the setting for each processing unit to perform the task.

16. A article as in claim 15, wherein the redistributing is done dynamically while the system is running and wherein the processing units comprise a central processing unit (CPU) and a special processing unit, and

wherein the task is created from one of a plurality of different software pipelines.

17. The article as in claim 16, wherein the special processing unit is a graphics processing unit (GPU) and wherein the GPU performs a plurality of graphics processing operations when the high performance setting is selected and the CPU performs the plurality of graphics processing operations when the low power setting is selected.

18. The article as in claim 16, wherein the special processing unit is a GPU and wherein the GPU performs a plurality of graphics processing operations when the low power setting is selected and the CPU performs the plurality of graphics processing operations when the high performance setting is selected.

19. The article as in claim 15, wherein the task is at least one of a graphics rendering process, a image processing process, a signal processing process, a Bayer filtering process, a video decoding process, or any combination thereof.

20. The article as in claim 15, wherein the setting is selected from a group that includes

a dynamic mode wherein the processing units are automatically chosen to prevent power or thermal overload based on a threshold.

21. The article as in claim 15, wherein the determination of values associated with the setting for each processing unit to perform the task includes determining the power consumption value, performance value, or performance and power consumption ratio for each processing unit to perform the task under a plurality of loads.