Method and apparatus for controlling operating parameters in a computer system

1. A method for controlling one or more operating parameters in a computer system, comprising:

until specified values for one or more operating parameters are achieved, performing the following operations:

operating the computer system using a specified load profile;

determining whether the specified load profile produces the specified values for the one or more operating parameters; and

if the specified load profile does not produce the specified values for the one or more operating parameters, adjusting the specified load profile, which involves using a pulse-width modulation technique to adjust a duty cycle between a first workload and a second workload.

2. The method of claim 1 , wherein prior to operating the computer system using the specified load profile, the method further comprises generating the specified load profile.

3. The method of claim 1 , wherein the specified load profile cycles between the first workload which produces a first resource-utilization level and the second workload which produces a second resource-utilization level, wherein the first resource-utilization level is greater than the second resource-utilization level.

4. The method of claim 3 , wherein the first resource-utilization level uses substantially all of the resources on the computer system.

5. The method of claim 3 , wherein the second resource-utilization level uses substantially none of the resources on the computer system.

6. The method of claim 3 ,

wherein the first workload is executed for a first time period within a given cycle; and

wherein the second workload is executed for a second time period within the given cycle.

7. The method of claim 6 , wherein if the specified load profile produces values for the one or more operating parameters which are below the specified values for the one or more operating parameters, adjusting the specified load profile involves increasing the first time period and decreasing the second time period for the given cycle of the specified load profile.

8. The method of claim 6 , wherein if the specified load profile produces values for the one or more operating parameters which are above the specified values for the one or more operating parameters, adjusting the specified load profile involves decreasing the first time period and increasing the second time period for the given cycle of the specified load profile.

9. The method of claim 1 , wherein the one or more operating parameters include one or more of:

a resource-utilization level;

a temperature; and

a power-consumption level.

10. The method of claim 1 ,

wherein the one or more operating parameters include a specified resource-utilization level; and

wherein if the specified load profile produces the specified resource-utilization level, the method further comprises determining the power consumed by the computer system at the specified resource-utilization level.

11. The method of claim 10 , wherein the specified resource-utilization level includes a utilization level of one or more of:

throughput;

transaction latencies;

queue lengths;

central processing unit (CPU) load;

memory load;

cache load;

I/O traffic;

bus saturation metrics;

FIFO overflow statistics; and

disk-related metrics.

12. The method of claim 1 ,

wherein the one or more operating parameters include a power-consumption level; and

wherein if the specified load profile produces the specified power-consumption level, the method further comprises analyzing the performance of the computer system while the computer system is operating at the specified power-consumption level.

13. A computer-readable storage medium storing instructions that when executed by a computer cause the computer to perform a method for controlling one or more operating parameters in a computer system, wherein the method comprises:

until specified values for one or more operating parameters are achieved, performing the following operations:

operating the computer system using a specified load profile;

determining whether the specified load profile produces the specified values for the one or more operating parameters; and

if the specified load profile does not produce the specified values for the one or more operating parameters, adjusting the specified load profile, which involves using a pulse-width modulation technique to adjust a duty cycle between a first workload and a second workload.

14. The computer-readable storage medium of claim 13 , wherein prior to operating the computer system using the specified load profile, the method further comprises generating the specified load profile.

15. The computer-readable storage medium of claim 13 , wherein the specified load profile cycles between the first workload which produces a first resource-utilization level and the second workload which produces a second resource-utilization level, wherein the first resource-utilization level is greater than the second resource-utilization level.

16. The computer-readable storage medium of claim 15 , wherein the first resource-utilization level uses substantially all of the resources on the computer system.

17. The computer-readable storage medium of claim 15 , wherein the second resource-utilization level uses substantially none of the resources on the computer system.

18. The computer-readable storage medium of claim 15 ,

wherein the first workload is executed for a first time period within a given cycle; and

wherein the second workload is executed for a second time period within the given cycle.

19. The computer-readable storage medium of claim 18 , wherein if the specified load profile produces values for the one or more operating parameters which are below the specified values for the one or more operating parameters, adjusting the specified load profile involves increasing the first time period and decreasing the second time period for the given cycle of the specified load profile.

20. The computer-readable storage medium of claim 18 , wherein if the specified load profile produces values for the one or more operating parameters which are above the specified values for the one or more operating parameters, adjusting the specified load profile involves decreasing the first time period and increasing the second time period for the given cycle of the specified load profile.

21. The computer-readable storage medium of claim 13 , wherein the one or more operating parameters include one or more of:

a resource-utilization level;

a temperature; and

a power-consumption level.

22. The computer-readable storage medium of claim 13 ,

wherein the one or more operating parameters include a specified resource-utilization level; and

wherein if the specified load profile produces the specified resource-utilization level, the method further comprises determining the power consumed by the computer system at the specified resource-utilization level.

23. The computer-readable storage medium of claim 22 , wherein the specified resource-utilization level includes a utilization level of one or more of:

throughput;

transaction latencies;

queue lengths;

central processing unit (CPU) load;

memory load;

cache load;

I/O traffic;

bus saturation metrics;

FIFO overflow statistics; and

disk-related metrics.

24. The computer-readable storage medium of claim 13 ,

wherein the one or more operating parameters include a power-consumption level; and

wherein if the specified load profile produces the specified power-consumption level, the method further comprises analyzing the performance of the computer system while the computer system is operating at the specified power-consumption level.

25. An apparatus that controls one or more operating parameters in a computer system, comprising:

a load-generation mechanism configured to operate the computer system using a specified load profile;

an analysis mechanism configured to determine whether the specified load profile produces the specified values for the one or more operating parameters; and

an adjustment mechanism configured to adjust the specified load profile if the specified load profile does not produce the specified values for the one or more operating parameters, wherein while adjusting the specified load profile, the adjustment mechanism is configured to use a pulse-width modulation technique to adjust a duty cycle between a first workload and a second workload;

wherein the load-generation mechanism, the analysis mechanism, and the adjustment mechanism are configured to be operated until specified values for one or more operating parameters are achieved.