Power cap lower bound exploration in a server environment

A computer program product for determining a safe lower bound for a commonly powered data processing system, the computer program product comprising:

• a computer readable tangible storage device having computer usable program code embodied therewith, the computer program product comprising:
• computer usable program code configured to operate the data processing system using at least one nominal operating parameter during an exploration periodicity;
• wherein the at least one nominal operating parameter is clock speed;
• computer usable program code configured to determine whether a calibration period is occurring;
• computer usable program code configured to calibrate the data processing system up to a measurement interval duration expiration, wherein the computer usable program code configured to calibrate further comprises:
• computer usable program code configured to set the clock speed of at least one integrated circuit of the data processing system to a performance floor;
• computer usable program code configured to determine whether system utilization of the data processing system exceeds the utilization threshold, responsive to setting the clock speed;
• computer usable program code configured to allow a delay before measurement after setting the clock speed;
• computer usable program code configured to accumulate at least two power measurements, responsive to allowing a delay before measurement;
• computer usable program code configured to average the at least two power measurements to form a power average;
• computer usable program code configured to determine whether the power average exceeds a maximum power average;
• computer usable program code configured to store the power average as the maximum power average, responsive to a determination that the power average exceeds the maximum power average;
• and
• computer usable program code configured to set a minimum power cap based on the maximum power average;
• and
• computer usable program code configured to repeat operating the data processing system using the at least one nominal operating parameter.

A data processing system comprising:

• a bus;
• a storage device connected to the bus, wherein computer usable code is located in the storage device;
• a communication unit connected to the bus;
• a processing unit connected to the bus, wherein the processing unit executes the computer usable code for determining a safe lower bound for a commonly powered data processing system wherein the processing unit executes the computer usable program code to operate the data processing system using at least one nominal operating parameter during an exploration periodicity;
• wherein the at least one nominal operating parameter is clock speed;
• determine whether a calibration period is occurring;
• calibrate the data processing system up to a measurement interval duration expiration;
• and repeatedly operate the data processing system using the at least one nominal operating parameter, wherein in executing computer usable code to calibrate, the processor executes computer usable code to set the clock speed of at least one integrated circuit of the data processing system to a performance floor;
• determine whether system utilization of the data processing system exceeds the utilization threshold, responsive to setting the clock speed;
• allow a delay before measurement after setting the clock speed;
• accumulate at least two power measurements, responsive to allowing a delay before measurement;
• average the at least two power measurements to form a power average;
• determine whether the power average exceeds a maximum power average;
• store the power average as the maximum power average, responsive to a determination that the power average exceeds the maximum power average;
• and set a minimum power cap based on the maximum power average.