Selecting method, computer product, selecting apparatus, and recording medium

1. A selecting method comprising:

obtaining by a computer, for each operation state combination for a processor of which element operation states are changeable, a state information record that indicates operation states of the operation state combination;

measuring by the computer, for each obtained state information record, a power consumption value and a processing performance value of the processor after the processor is switched to the operation states indicated by the state information record, the power consumption value and the processing performance value being measured by executing a specific program on the processor after the processor is switched to the operation states indicated by the state information record; and

selecting by the computer, based on the measured processing performance values and for each predetermined power consumption value among a plurality of predetermined power consumption values that differ, a state information record for which the measured power consumption value is the predetermined power consumption value or less among the obtained state information records.

2. The selecting method according to claim 1 , wherein

the selecting of the state information record includes selecting a state information record indicating operation states for which processing performance indicated by the measured processing performance value is highest among state information records for which the measured power consumption value is the predetermined power consumption value or less.

3. The selecting method according to claim 1 and further comprising

generating by the computer, a table that associates a specified power consumption value that corresponds to a predetermined power consumption value, and the state information record selected for the predetermined power consumption value that corresponds to the specified power consumption value.

4. The selecting method according to claim 3 and further comprising:

receiving by the processor, an upper limit value for the power consumption value;

searching by the processor, the generated table for a state information record associated with the specified power consumption value closest to the received upper limit value among the state information records associated with a specified power consumption value that is less than the received upper limit value; and

switching by the processor, to the operation states indicated by the retrieved state information record.

5. The selecting method according to claim 4 and further comprising

measuring by the processor, a current power consumption value, wherein

the searching for the state information record includes searching the generated table for a state information record that indicates operation states different from current operation states of the processor among the state information records associated with a specified power consumption value that is less than the received upper limit value, when the measured current power consumption value is greater than the received upper limit value.

6. The selecting method according to claim 5 and further comprising

measuring by the processor, the current power consumption value, wherein

the searching for the state information record state information includes searching the generated table for the state information record that indicates operation states different from the current operation states of the processor among the state information records associated with a specified power consumption value that is less than the received upper limit value, when the measured current power consumption value is the received upper limit value or less and a difference of the measured current power consumption value and the received upper limit value is a given value or greater, and includes refraining from searching when the measured current power consumption value is the received upper limit value or less and the difference of the measured current power consumption value and the received upper limit value is less than the given value.

7. A selecting method comprising:

obtaining by a computer, for each operation state combination for a processor of which element operation states are changeable, a state information record that indicates operation states of the operation state combination;

measuring by the computer, for each obtained state information record, a power consumption value and a processing performance value of the processor after the processor is switched to the operation states indicated by the state information record, the power consumption value and the processing performance value being measured by executing a specific program on the processor after the processor is switched to the operation states indicated by the state information record; and

selecting by the computer, for each specified power consumption value among a plurality of specified power consumption values that differ, a state information record among the obtained state information records, the state information record being selected based on the measured processing performance value corrected based on a rate of the measured power consumption value and the specified power consumption value.

8. The selecting method according to claim 7 , wherein

the selecting of the state information record includes selecting a state information record indicating operation states for which processing performance indicated by the corrected processing performance value is highest.

9. The selecting method according to claim 7 and further comprising

correcting by the computer, a frequency specified when the power consumption value and the processing performance value are measured, the specified frequency being corrected for each specified power consumption value and based on the rate concerning the selected state information record.

10. The selecting method according to claim 7 and further comprising

generating by the computer, a table that associates a specified power consumption value, the state information record selected for the specified power consumption value, and a frequency corrected for the specified power consumption value.

11. The selecting method according to claim 10 and further comprising:

receiving by the processor, an upper limit value for the power consumption value;

searching by the processor, the generated table for a state information record and a frequency associated with the specified power consumption value closest to the received upper limit value among state information records and frequencies associated with a specified power consumption value that is less than the received upper limit value; and

switching by the processor, to the operation states indicated by the retrieved state information record and changing a frequency of the processor to the retrieved frequency.

12. The selecting method according to claim 11 and further comprising

measuring by the processor, a current power consumption value, wherein

the searching for the state information record and the frequency includes searching the generated table for a frequency and a state information record that indicates operation states different from current operation states of the processor among the state information records and the frequencies associated with a specified power consumption value that is less than the received upper limit value, when the measured current power consumption value is greater than the received upper limit value.

13. The selecting method according to claim 12 and further comprising

measuring by the processor, the current power consumption value, wherein

the searching for the state information and the frequency includes searching the generated table for the state record that indicates operation states different from the current operation states of the processor among the state information records associated with a specified power consumption value that is less than the received upper limit value, when the measured current power consumption value is the received upper limit value or less and a difference of the measured current power consumption value and the received upper limit value is a given value or greater, and includes refraining from searching when the measured current power consumption value is the received upper limit value or less and the difference of the measured current power consumption value and the received upper limit value is less than the given value.

14. A non-transitory, computer-readable recording medium storing therein a selecting program that causes a computer to execute a process comprising:

obtaining for each operation state combination for a processor of which element operation states are changeable, a state information record that indicates operation states of the operation state combination;

measuring for each obtained state information record, a power consumption value and a processing performance value of the processor after the processor is switched to the operation states indicated by the state information record, the power consumption value and the processing performance value being measured by executing a specific program on the processor after the processor is switched to the operation states indicated by the state information record; and

selecting based on the measured processing performance values and for each predetermined power consumption value among a plurality of predetermined power consumption values that differ, a state information record for which the measured power consumption value is the predetermined power consumption value or less among the obtained state information records.