Thread management based on device power state

• US 9,027,027 B2
• Filed: 06/09/2008
• Issued: 05/05/2015
• Est. Priority Date: 06/09/2008
• Status: Active Grant

• Current Assignee: Microsoft Technology Licensing LLC (Microsoft Corporation)
• Original Assignee: Microsoft Technology Licensing LLC (Microsoft Corporation)
• Inventors: Vals, Angelo Renato, Laughlin, Chetley T.
• Primary Examiner(s): Wai, Eric C
• Application Number:
  US12/135,213
• Publication Number:
  US 20090307696A1
• Time in Patent Office: 2,521 Days
• US Class Current: 718/103
• CPC Class Codes: G06F 9/4893 taking 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

Managing threads for executing on a computing device based on a power state of the computing device. A power priority value corresponding to each of the threads is compared to a threshold value associated with the power state. The threads having an assigned power priority value that violates the threshold value are suspended from executing, while the remaining threads are scheduled for execution. When the power state of the computing device changes, the threads are re-evaluated for suspension or execution. In an embodiment, the threads on a mobile computing device are managed to maintain the processor in a low power state to reduce power consumption.

Claims

1. A system comprising:

a memory area for storing a list of active threads being executed by a mobile computing device and a list of suspended threads, said memory area further storing a power priority value for each of the active threads and the suspended threads, said memory area storing a default power priority value for each of the active threads and suspended threads if a power profile does not exist, wherein the default power priority value prevents the threads from running in any power state other than an active power state, wherein the power state comprises at least one of the following;

ON, IDLE, ACTIVE, STANDBY, RECHARGING, BATTERY POWER LEVEL, or BACKLIGHT OFF; and

a processor programmed to;

determine a power state of the mobile computing device upon detection of a change in the power state, the determined power state representing one of a plurality of power states each mapped to one of a plurality of threshold values;

identify one of the plurality of threshold values corresponding to the determined power state;

compare the identified threshold value to the power priority value for each of the active threads and suspended threads individually; and

alter the list of active threads and the list of suspended threads by moving at least one thread between the list of active threads and the list of suspended threads based on the comparison to manage the power state of the mobile computing device.

2. The system of claim 1, wherein the memory area further stores an active queue for storing the list of active threads and a suspended queue for storing the list of suspended threads.

3. The system of claim 1, wherein a first thread in the list of active threads has a power priority value less than the identified threshold value, wherein a second thread in the list of active threads has a power priority value greater than the identified threshold value, wherein the second thread requires a resource blocked by the first thread, and further comprising assigning a power priority value of the second thread to the first thread to enable the first thread to execute to release the resource.

4. The system of claim 1, wherein the processor is further programmed to identify, from the list of active threads, one or more threads each having the power priority value less than the identified threshold value, and wherein the processor alters the list of active threads and the list of suspended threads by moving the identified one or more threads from the list of active threads to the list of suspended threads.

5. The system of claim 1, wherein the processor is further programmed to identify, from the list of suspended threads, one or more threads each having the power priority value greater than or equal to the identified threshold value, and wherein the processor alters the list of active threads and the list of suspended threads by moving the identified one or more threads from the list of suspended threads to the list of active threads.

6. The system of claim 1, further comprising means for maintaining the list of active threads and the list of suspended threads as a function of the power priority value and the threshold value.

7. The system of claim 1, further comprising means for managing execution of the threads based on the power state of the mobile computing device.

8. The system of claim 1, wherein the processor is further programmed to alter the list of active threads and the list of suspended threads as a part of an operating system scheduler.

9. The system of claim 1, wherein the processor is further programmed to alter the list of active threads and the list of suspended threads as a part of a power priority monitoring service.

10. A method for managing threads for execution based on a power state of a computing device, said method comprising:

identifying a plurality of threads for execution on a computing device, wherein a default power priority value is associated with each of the identified threads if a power profile does not exist, wherein the default power priority value prevents the identified threads from running in any power state other than an active power state, wherein the power state comprises at least one of the following;

ON, IDLE, ACTIVE, STANDBY, RECHARGING, BATTERY POWER LEVEL, or BACKLIGHT OFF;

determining a power priority value for each of the identified threads, the power priority value being distinct from a process priority value;

determining a threshold value for the computing device, said threshold value being one of a plurality of threshold values each corresponding to one of a plurality of power states of the computing device;

comparing the determined threshold value to the determined power priority value for each of the identified threads individually;

selecting one or more of the plurality of threads based on said comparing; and

executing the selected one or more threads.

11. The method of claim 10, wherein one or more of the plurality of threads are associated with an application program, and further comprising:

accessing the power profile for the application program, said power profile defining a power priority value for each of the one or more threads; and

assigning the power priority value to each of the one or more threads based on the accessed power profile.

12. The method of claim 10, further comprising:

defining a plurality of power states of the computing device; and

defining the threshold value for each of the defined plurality of power states.

13. The method of claim 10, further comprising filtering the threads based on the power priority value for each of the threads.

14. The method of claim 10, wherein the determined threshold value corresponds to a battery power level for the computing device.

15. The method of claim 10, wherein selecting the one or more of the plurality of threads comprises selecting one or more of the plurality of threads having a determined power priority value greater than or equal to the determined threshold value.

16. The method of claim 10, further comprising suspending one or more of the threads having a determined power priority value less than the determined threshold value.

17. One or more computer storage media having computer-executable components, said components comprising:

a detection component for receiving a request for execution of a thread, for assigning a default power priority value to the thread if a power profile does not exist, and for determining a power priority value associated with the thread if the power profile exists, wherein the default power priority value prevents the thread from running in any power state other than an active power state, wherein the power state comprises at least one of the following;

ON, IDLE, ACTIVE, STANDBY, RECHARGING, BATTERY POWER LEVEL, or BACKLIGHT OFF, the power priority value being distinct from a process priority value;

a state component for determining a threshold value for a computing device, said threshold value being one of a plurality of threshold values each corresponding to one of a plurality of power states of the computing device;

a priority component for comparing the power priority value associated with the thread and determined by the detection component with the threshold value determined by the state component; and

a dispatcher component for scheduling the thread for execution if the power priority value determined by the detection component violates the threshold value determined by the state component, and for suspending execution of the thread if otherwise.

18. The computer storage media of claim 17, wherein the dispatcher component schedules the thread for execution if the power priority value exceeds the threshold value.

19. The computer storage media of claim 17, wherein the computing device has at least one processor associated therewith, and wherein the power state corresponds to a power state associated with the processor.

20. The computer storage media of claim 17, further comprising an inheritance component for increasing the power priority value of the thread above the threshold value if the thread is blocking a resource required by another thread being executed.