Instruction scheduling based on power estimation

• US 20030126476A1
• Filed: 01/02/2002
• Published: 07/03/2003
• Est. Priority Date: 01/02/2002
• Status: Active Grant

• Current Assignee: Intel Corporation
• Original Assignee: Intel Corporation
• Inventors: Greene, Michael A.
• Granted Patent: US 6,775,787 B2
• Time in Patent Office: Days
• US Class Current: 713/300
• 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 9/3836 Instruction issuing, e.g. dynamic instruction scheduling or out of order instruction execution
• CPC Class Codes: G06F 9/3854 Instruction completion, e.g. retiring, committing or graduating
• CPC Class Codes: G06F 9/3858 Result writeback, i.e. updating the architectural state or memory
• CPC Class Codes: Y02D 10/00 Energy efficient computing, e.g. low power processors, power management or thermal management

Abstract

In an embodiment, an apparatus includes a memory to include at least one power value associated with at least one instruction. The at least one power value indicating an amount of power required to execute the at least one associated instruction by the apparatus. The apparatus also includes an instruction scheduler to receive the at least one power value and the at least one instruction. The instruction scheduler is to schedule the at least one instruction for execution by at least one functional unit based on the at least one associated power value.

Claims

1. A method comprising:

receiving a number of instructions;

receiving a number of power values for the number of instructions indicating an amount of power required to execute the number of instructions by an electronic device; and

scheduling the number of instructions for execution by the electronic device based on the number of power values.

2. The method of claim 1, wherein the scheduling of the instruction for execution by the electronic device based on the power value comprises,

determining whether power being consumed by the electronic device is within a range between a minimum power threshold and a maximum power threshold;

and

modifying the number of instructions for execution upon determining that the power being consumed by the electronic device is not within the range between the minimum power threshold and the maximum power threshold.

3. The method of claim 2, wherein modifying the number of instructions for execution upon determining that the power being consumed by the electronic device is not within the range between the minimum power threshold and the maximum power threshold comprises,

increasing the number of instructions scheduled to be executed in a next instruction cycle, upon determining that the power being consumed by the electronic device is below a minimum power threshold.

4. The method of claim 3, wherein increasing the number of instructions scheduled to be executed in the next instruction cycle comprises, adding a number of artificial instructions to be scheduled for execution in the next instruction cycle.

5. The method of claim 2, wherein modifying the number of instructions for execution upon determining that the power being consumed by the electronic device is not within the range between the minimum power threshold and the maximum power threshold comprises,

reducing the number of instructions scheduled to be executed in a next instruction cycle, upon determining that the power being consumed by the electronic device is above a maximum power threshold.

6. The method of claim 1, wherein the scheduling of the instruction for execution by the electronic device based on the power value comprises,

determining whether a change in current over time being consumed by the electronic device is greater than a threshold value based on the power values of the number of instructions scheduled for execution.

7. The method of claim 1, wherein the amount of power required to execute the number of instructions by the electronic device includes the amount of power required to execute the number of instructions by a number of functional units within the electronic device.

8. The method of claim 1, wherein the amount of power required to execute the number of instructions by the electronic device includes the amount of power required to retrieve data from a cache within the electronic device.

9. The method of claim 1, wherein the amount of power required to execute the number of instructions by the electronic device includes the amount of power required to retrieve data from a memory external to the electronic device.

10. A method comprising:

receiving a number of instructions;

receiving a number of power values for the number of instructions indicating an amount of power required to execute the number of instructions by a processor; and

scheduling the number of instructions for execution by the processor based on the number of power values, wherein the scheduling of the number of instructions comprises,

determining whether power being consumed by the processor is within a range between a minimum power threshold and a maximum power threshold;

determining whether a change in current over time being consumed by the processor is greater than a current change threshold value based on the power values of the number of instructions scheduled for execution; and

modifying the number of instructions for execution upon determining that the power being consumed by the electronic device is not within the range between the minimum power threshold and the maximum power threshold and upon determining that the change in current over time being consumed by the processor is greater than the current change threshold value.

11. The method of claim 10, wherein modifying the number of instructions for execution comprises increasing the number of instructions scheduled to be executed in a next instruction cycle.

12. The method of claim 11, wherein increasing the number of instructions scheduled to be executed in the next instruction cycle comprises adding a number of artificial instructions to be scheduled for execution in the next instruction cycle.

13. The method of claim 10, wherein modifying the number of instructions for execution comprises reducing the number of instructions scheduled to be executed in a next instruction cycle.

14. An apparatus comprising:

a memory to include at least one power value associated with at least one instruction, the at least one power value indicating an amount of power required to execute the at least one associated instruction by the apparatus; and

an instruction scheduler to receive the at least one power value and the at least one instruction and to schedule the at least one instruction for execution by at least one functional unit based on the at least one associated power value.

15. The apparatus of claim 14, comprising power value lookup logic coupled to the memory and the instruction scheduler, the power value lookup logic to determine a power value for the at least one instruction based on the at least one power value associated with the at least one instruction.

16. The apparatus of claim 15, comprising a decoder coupled to the power value lookup logic and the instruction scheduler, the decoder to retrieve the at least one instruction from an instruction buffer and to transmit the at least one instruction to the power value lookup logic.

17. The apparatus of claim 14, wherein the amount of power required to execute the number of instructions by the apparatus includes the amount of power required to execute the number of instructions by the at least one functional unit.

18. The apparatus of claim 14, wherein the amount of power required to execute the number of instructions by the apparatus includes the amount of power required to retrieve data from a cache within the apparatus.

19. The apparatus of claim 14, wherein the amount of power required to execute the number of instructions by the electronic device includes the amount of power required to retrieve data from an external memory.

20. A system comprising:

a memory to include a number of instructions; and

a processor coupled to the memory, the processor comprising,

a number of functional units to execute the number of instructions;

a lookup table memory to include at least one power value associated with at least one of the number of instructions; and

an instruction scheduler to receive the at least one power value and the at least one of the number of instructions, the instruction scheduler to schedule the at least one of the number of instructions for execution by one of the number of functional units based on the at least one power value.

21. The system of claim 20, wherein the at least one power value indicates an amount of power required to execute the associated instruction.

22. The system of claim 21, wherein the processor comprises a number of caches, wherein the amount of power required to execute the associated instruction comprises an amount of power required to retrieve data from one of the number of caches.

23. The system of claim 21, wherein the amount of power required to execute the associated instruction comprises an amount of power required to retrieve data from the memory.

24. The system of claim 21, wherein the amount of power required to execute the associated instruction comprises the amount of power required to execute the associated instruction by one of the number of functional units.

25. A machine-readable medium that provides instructions, which when executed by a machine, cause said machine to perform operations comprising:

receiving a number of instructions;

receiving a number of power values for the number of instructions indicating an amount of power required to execute the number of instructions by an electronic device; and

scheduling the number of instructions for execution by the electronic device based on the number of power values.

26. The machine-readable medium of claim 25, wherein the scheduling of the instruction for execution by the electronic device based on the power value comprises,

determining whether power being consumed by the electronic device is within a range between a minimum power threshold and a maximum power threshold;

and

modifying the number of instructions for execution upon determining that the power being consumed by the electronic device is not within the range between the minimum power threshold and the maximum power threshold.

27. The machine-readable medium of claim 26, wherein modifying the number of instructions for execution upon determining that the power being consumed by the electronic device is not within the range between the minimum power threshold and the maximum power threshold comprises,

increasing the number of instructions scheduled to be executed in a next instruction cycle, upon determining that the power being consumed by the electronic device is below a minimum power threshold.

28. The machine-readable medium of claim 27, wherein increasing the number of instructions scheduled to be executed in the next instruction cycle comprises, adding a number of artificial instructions to be scheduled for execution in the next instruction cycle.

29. The machine-readable medium of claim 26, wherein modifying the number of instructions for execution upon determining that the power being consumed by the electronic device is not within the range between the minimum power threshold and the maximum power threshold comprises,

reducing the number of instructions scheduled to be executed in a next instruction cycle, upon determining that the power being consumed by the electronic device is above a maximum power threshold.

30. The machine-readable medium of claim 25, wherein the scheduling of the instruction for execution by the electronic device based on the power value comprises,

determining whether a change in current over time being consumed by the electronic device is greater than a threshold value based on the power values of the number of instructions scheduled for execution.