Systems and methods for managing power consumption and performance of a processor
Processor-management techniques that purposely alternate a processor between an operating state and a non-operating state while the processor is executing the workload. The techniques leverage the “ultra-low-power” non-operating states of many processors to provide predictable power and/or frequency control of the processor. These techniques can provide better performance than known clock-throttling and dynamic voltage and frequency scaling schemes for controlling processors.
1. A method of controlling power consumption of a computing system that includes a processor having an operating state in which the processor is powered to execute workload instructions, a non-operating state in which the processor is not powered to execute the workload instructions, and an idle state in which no workload for the processor is present, the method comprising:
receiving a workload-power-state setting for controlling functioning of the processor; and
controlling the processor as a function of the workload-power-state setting, wherein said controlling includes alternating the processor between the operating state and the non-operating state while the processor is not in the idle state.
2. A method according to claim 1 , wherein said alternating the processor between the operating state and the non-operating state includes operating the processor for a fraction r of an alternation period in the operating state and setting the processor into the non-operating state for a fraction (1−r) of the alternation period.
3. A method according to claim 2 , wherein the processor has an operating frequency, f oper , in the operating state and said receiving the workload-power-state setting includes receiving a desired frequency, f WPS , the method further comprising calculating the fraction r from the equation:
r=f WPS /f oper .
4. A method according to claim 2 , wherein the processor has a power consumption, P oper , in the operating state, the processor has a power consumption P C during the non-operating state, and said receiving the workload-power-state setting includes receiving a desired power cap, P WPS , the method further comprising calculating the fraction r from the equation:
r =( P WPS −P C )/( P oper −P C ).
5. A method according to claim 1 , wherein the processor has a minimum operating frequency and a corresponding minimum-operating power consumption and said alternating the processor between the operating state and the non-operating state includes alternating the processor between the operating state and a non-operating state having a power consumption lower than the minimum-operating power consumption.
6. A method according to claim 5 , wherein the processor has a normal-maximum-operating-frequency state and a corresponding normal-maximum power consumption and said alternating the processor between the operating state and the non-operating state includes alternating the processor between the normal-maximum-operating-frequency state and a non-operating state having a power consumption lower than the minimum-operating power consumption.
7. A method according to claim 1 , wherein the processor has a normal-maximum-operating-frequency state and a corresponding normal-maximum power consumption and said alternating the processor between the operating state and the non-operating state includes alternating the processor between the normal-maximum-operating-frequency state and the non-operating state.
8. A method according to claim 1 , wherein said receiving the workload-power-state setting includes receiving the workload-power-state setting via a user interface.
9. A method according to claim 1 , wherein said receiving the workload-power-setting includes receiving the workload-power-state setting from an application that generates the workload.
10. A method according to claim 1 , wherein said receiving the workload-power-setting includes receiving the workload-power-state setting via an input to the computing system from a source external to the computing system.
11. A method according to claim 1 , wherein the processor has a zero-frequency extrapolated power consumption, P 0 , extrapolated from a power-consumption-to-frequency curve for the processor and said alternating the processor between the operating state and the non-operating state includes alternating the processor between the operating state and a non-operating state having a power consumption, P C , that is lower than P 0 .
12. A machine-readable medium containing non-transitory machine-executable instructions for performing a method of controlling power consumption of a computing system that includes a processor having an operating state in which the processor is powered to execute workload instructions, a non-operating state in which the processor is not powered to execute the workload instructions, and an idle state in which no workload for the processor is present, said non-transitory machine-executable instructions comprising:
a first set of machine-executable instructions for receiving a workload-power-state setting for controlling functioning of the processor; and
a second set of machine-executable instructions for controlling the processor as a function of the workload-power-state setting, wherein said second set of machine-executable instructions includes a third set of machine-executable instructions for alternating the processor between the operating state and the non-operating state while the processor is not in the idle state.
13. A machine-readable medium according to claim 12 , wherein said third set of machine-executable instructions includes machine-executable instructions for operating the processor for a fraction r of an alternation period in the operating state and for setting the processor into the non-operating state for a fraction (1−r) of the alternation period.
14. A machine-readable medium according to claim 13 , wherein the processor has an operating frequency, f oper , in the operating state and said first set of machine-executable instructions includes machine-executable instructions for receiving a desired frequency, f WPS , said non-transitory machine-executable instructions further comprising machine-executable instructions for calculating the fraction r from the equation: r=f WPS /f oper .
15. A machine-readable medium according to claim 13 , wherein the processor has a power consumption, P oper , in the operating state, the processor has a power consumption P C during the non-operating state, and said first set of machine-executable instructions includes machine-executable instructions for receiving a desired power cap, P WPS , said non-transitory machine-executable instructions further comprising machine-executable instructions for calculating the fraction r from the equation: r=(P WPS −P C )/(P oper −P C ).
16. A machine-readable medium according to claim 12 , wherein the processor has a minimum operating frequency and a corresponding minimum-operating power consumption and said third set of machine-executable instructions includes machine-executable instructions for alternating the processor between the operating state and a non-operating state having a power consumption lower than the minimum-operating power consumption.
17. A machine-readable medium according to claim 16 , wherein the processor has a normal-maximum-operating-frequency state and a corresponding normal-maximum power consumption and said third set of machine-executable instructions includes machine-executable instructions for alternating the processor between the normal-maximum-operating-frequency state and a non-operating state having a power consumption lower than the minimum-operating power consumption.
18. A machine-readable medium according to claim 12 , wherein the processor has a normal-maximum-operating-frequency state and a corresponding normal-maximum power consumption and said third set of machine-executable instructions includes machine-executable instructions for alternating the processor between the normal-maximum-operating-frequency state and the non-operating state.
19. A machine-readable medium according to claim 12 , wherein said first set of machine-executable instructions includes machine-executable instructions for receiving the workload-power-state setting via a user interface.
20. A machine-readable medium according to claim 12 , wherein said first set of machine-executable instructions includes machine-executable instructions for receiving the workload-power-state setting from an application that generates the workload.
21. A machine-readable medium according to claim 12 , wherein said first set of machine-executable instructions includes machine-executable instructions for receiving the workload-power-state setting via an input to the computing system from a source external to the computing system.
22. A machine-readable medium according to claim 12 , wherein the processor has a zero-frequency extrapolated power consumption, P 0 , extrapolated from a power-consumption-to-frequency curve for the processor and said third set of machine-executable instructions includes machine-executable instructions for alternating the processor between the operating state and a non-operating state having a power consumption, P C , that is lower than P 0 .
23. A computing system, comprising:
a processor having an operating state in which said processor is powerable to execute workload instructions, a non-operating state in which said processor is not powered to execute the workload instructions, and an idle state in which no workload for the processor is present;
a memory; and
a workload-power-state manager stored in said memory and operatively configured to, when the computing system is operating:
receive a workload-power-state setting for controlling functioning of said processor; and
control said processor as a function of the workload-power-state setting, wherein said control includes alternating said processor between the operating state and the non-operating state while said processor is not in the idle state.
24. A computing system according to claim 23 , wherein said workload-power-state manager is configured to operate said processor for a fraction r of an alternation period in the operating state and set said processor into the non-operating state for a fraction (1−r) of the alternation period.
25. A computing system according to claim 24 , wherein said processor has an operating frequency, f oper , in the operating state and said workload-power-state manager is configured to receive a desired frequency, f WPS , and to calculate the fraction r from the equation: r=f WPS /f oper .
26. A computing system according to claim 24 , wherein said processor has a power consumption, P oper , in the operating state, said processor has a power consumption P C during the non-operating state, and said workload-power-state manager is configured to receive a desired power cap, P WPS , and to calculate the fraction r from the equation: r=(P WPS −P C )/(P oper −P C ).
27. A computing system according to claim 23 , wherein said processor has a minimum operating frequency and a corresponding minimum-operating power consumption and said workload-power-state manager is configured to alternate said processor between the operating state and a non-operating state having a power consumption lower than the minimum-operating power consumption.
28. A computing system according to claim 27 , wherein the at least one processor has a normal-maximum-operating-frequency state and a corresponding normal-maximum power consumption and said workload-power-state manager is configured to alternate said processor between the normal-maximum-operating-frequency state and a non-operating state having a power consumption lower than the minimum-operating power consumption.
29. A computing system according to claim 23 , wherein the processor has a normal-maximum-operating-frequency state and a corresponding normal-maximum power consumption and said workload-power-state manager is configured to alternate said processor between the normal-maximum-operating-frequency state and the non-operating state.
30. A computing system according to claim 23 , further comprising a user interface, wherein said workload-power-state manager is configured to receive the workload-power-state setting via said user interface.
31. A computing system according to claim 23 , wherein the computing system is configured to execute a workload generated by an application, wherein said workload-power-state manager is configured to receive the workload-power-state setting from the application.
32. A computing system according to claim 23 , further comprising an input from a source external to the computing system, wherein said workload-power-state manager is configured to receive the workload-power-state setting via said input.
33. A computing system according to claim 23 , wherein said processor has a zero-frequency extrapolated power consumption, P 0 , extrapolated from a power-consumption-to-frequency curve for the processor and said workload-power-state manager is configured to alternate said processor between the operating state and a non-operating state having a power consumption, P C , that is lower than P 0 .