Clock control method, and apparatus and medium therefor

• US 20030226049A1
• Filed: 03/07/2003
• Published: 12/04/2003
• Est. Priority Date: 09/08/2000
• Status: Active Grant

• Current Assignee: Fujitsu Client Computing Limited (Lenovo Group Ltd.)
• Original Assignee: Fujitsu Limited
• Inventors: Mantani, Tadashi
• Granted Patent: US 7,028,211 B2
• Time in Patent Office: Days
• US Class Current: 713/322
• CPC Class Codes: G06F 1/04 Generating or distributing clock signals or signals derived directly therefrom
• CPC Class Codes: G06F 1/3203 Power management, i.e. event-based initiation of a power-saving mode
• CPC Class Codes: G06F 1/324 by lowering clock frequency
• CPC Class Codes: G06F 1/329 by task scheduling
• CPC Class Codes: Y02D 10/00 Energy efficient computing, e.g. low power processors, power management or thermal management

Abstract

In the clock control of the present invention, CPU usage rate is calculated for each of a plurality of applications with respect to a maximum clock frequency attainable by the information processing apparatus, based on registered clock frequency necessary for executing each of the applications, and a system clock frequency determined by a total sum of the CPU usage rates is set in the apparatus. If the frequency with which this system clock frequency exceeds the maximum clock frequency increases, an apparatus upgrade necessity alarm is sent. Also, any one clock frequency from among a comfortable operation clock frequency for the application, a minimum clock frequency for the application to run, and a permissible system clock frequency corresponding to usage environmental conditions (power source state, temperature and noise) is set according to the usage environmental conditions. Thereby, optimum performance of the apparatus can be provided.

Claims

1. A clock control method for setting a determined system clock frequency in an information processing system, comprising:

a step of, when a plurality of applications are running, reading a clock frequency necessary for running of the applications from each of the applications, and registering the clock frequency in each of the plurality of applications;

a step of calculating a CPU usage rate for each application in the information processing system, with respect to a maximum clock frequency obtainable by the information processing system for running each of the plurality of applications, based on each registered clock frequency; and

a step of determining a system clock frequency for the information processing system, based on a total sum of calculated CPU usage rates for each application.

2. The clock control method according to claim 1, wherein, when said determined system clock frequency exceeds the maximum clock frequency, a clock frequency excess alarm is sent.

3. The clock control method according to claim 2, wherein, when the number of times that said system clock frequency exceeds the maximum clock frequency increases, said information processing system upgrade necessity alarm is activated.

4. The clock control method according to claim 1, wherein said clock frequency necessary for the running of the applications includes a first clock frequency at which the applications operate comfortably and a second clock frequency that is a minimum necessary for the applications to run, and when said information processing system is operating in a normal state, a first system clock frequency is determined based on the first clock frequency, while when the information processing system is operating in a specified state, a second system clock frequency is determined based on the second clock frequency, any one of the determined first and second system clock frequencies being set in the information processing system according to each state.

5. The clock control method according to claim 4, wherein said specified state is a case where a power source energy in said information processing system changes, and said second system clock frequency is set in the information processing system in place of said first system clock frequency according to a change of a detected remaining power source energy.

6. The clock control method according to claim 5, wherein an operation reservation time for said information processing system is set, and any one selected from among said first system clock frequency and said second system clock frequency is set in the information processing system such that an operation time calculated from the detected remaining power source energy is at least equal to the operation reservation time.

7. The clock control method according to claim 4, wherein the specified state is a case where a temperature in said information processing system changes, said system clock frequency is variable, and the system clock frequency is set in the information processing system, according to a change in a detected temperature.

8. The clock control method according to claim 7, wherein the second system clock frequency is set in said information processing system when the temperature is within a range in which erroneous operation of the information processing system occurs.

9. The clock control method according to claim 7, wherein said system clock frequency is increased by a predetermined width from the second system clock frequency and set as the system clock frequency in said information processing system when the temperature is close to the range in which erroneous operation of the information processing system occurs.

10. The clock control method according to claim 7, wherein said second system clock frequency is decreased by a predetermined width from said first system clock frequency and set as the system clock frequency in said information processing system when the temperature is far from a range in which erroneous operation of the information processing system occurs.

11. The clock control method according to claim 4, wherein the specified state is a case where external noise of said information processing system changes, said system clock frequency is variable, and the system clock frequency is set in the information processing system, according to a change in a detected external noise.

12. The clock control method according to claim 11, wherein, when information processing system noise level is within a permissible range with respect to an external noise level, said second system clock frequency is set in the information processing system.

13. The clock control method according to claim 11, wherein a permissible clock frequency corresponding to a noise level generated from said information processing system is prepared beforehand and, when a measured external noise level is higher than a noise level corresponding to the permissible noise clock frequency, said first system clock frequency is set in the information processing system.

14. The clock control method according to claim 11, wherein a permissible clock frequency corresponding to a noise level generated from said information processing system is prepared beforehand and, when a measured external noise level is lower than a noise level corresponding to the permissible noise clock frequency, the permissible clock frequency corresponding to the external noise level is set in the information processing system.

15. An information processing apparatus that can run a plurality of applications, comprising:

a memory unit which registers clock frequencies necessary for execution, obtained from each application, in each of a plurality of applications; and

a control unit which calculates a CPU usage rate of each of the applications for the information processing apparatus with respect to a maximum clock frequency obtainable by the information processing apparatus for running each of the applications, based on each of the clock frequency registered in the memory section, determines a system clock frequency for the information processing apparatus based on a total sum of calculated CPU usage rates for each application, and sets the system clock frequency.

16. The information processing apparatus according to claim 15, wherein said control unit sends a clock frequency excess alarm when the determined system clock frequency exceeds the maximum clock frequency.

17. The information processing apparatus according to claim 16, wherein said control unit sends the information processing system upgrade necessity alarm when the number of times that the system clock frequency exceeds the maximum clock frequency increases.

18. The information processing apparatus according to claim 15, wherein:

said memory unit registers a first clock frequency at which applications can be operated comfortably, and a second clock frequency necessary for minimum operation of the applications, as the clock frequency necessary required for execution of the applications; and

said control unit determines a first system clock frequency based on the first clock frequency when the information processing apparatus is operating in a normal state, determines a second system clock frequency based on the second clock frequency when the information processing apparatus is operating in a specific state, and sets any one of the determined first and second system clock frequencies according to each state.

19. The information processing apparatus according to claim 18, wherein said control unit detects a change of the remaining power source energy in the specific state, and sets said second system clock frequency in place of said first system clock frequency according to the detected change.

20. The information processing apparatus according to claim 19, wherein said control unit selects and sets any one of said first system clock frequency and said second system clock frequency, so that an operation time calculated from a detected remaining power source energy is at least equal to a previously set operation reservation time.

21. The information processing apparatus according to claim 18, wherein said control unit measures a temperature inside the information processing apparatus as the specified state, varies the system clock frequency corresponding to the measured temperature, and sets the system clock frequency.

22. The information processing apparatus according to claim 21, wherein said control unit sets said second system clock frequency when the temperature is within a range in which erroneous operation of the information processing system occurs.

23. The information processing apparatus according to claim 21, wherein said control unit increases the system clock frequency by a predetermined width from said second system clock frequency and sets it as the system clock frequency when the temperature is close to the range in which erroneous operation of the information processing system occurs.

24. The information processing apparatus according to claim 21, wherein said control unit decreases said second system clock frequency by a predetermined width from said first system clock frequency and sets it as the system clock frequency when the temperature is far from a range in which erroneous operation of the information processing system occurs.

25. The information processing apparatus according to claim 18, wherein said control unit measures external noise as the specified state, varies the system clock frequency according to a change in the external temperature, and sets the system clock frequency.

26. The information processing apparatus according to claim 25, wherein said control unit sets said second system clock frequency when the noise of the information processing system is within a permissible range with respect to the amount of external noise.

27. The information processing apparatus according to claim 25, wherein a permissible clock frequency corresponding to a noise level generated from the information processing apparatus is registered in said memory unit, and said control unit sets said first system clock frequency when a level of measured external noise is higher than a noise level corresponding the permissible clock frequency.

28. The information processing apparatus according to claim 25, wherein a permissible clock frequency corresponding to a noise level generated from the information processing apparatus is registered in said memory unit, and said control unit sets a permissible clock frequency corresponding to an external noise level when a level of measured external noise is lower than a noise level corresponding the permissible clock frequency.

29. A recording medium for:

when a plurality of applications are running, reading a first clock frequency at which the applications operate comfortably and a second clock frequency that is a minimum necessary for the applications to run, and registering these frequencies for each of the applications;

calculating a CPU usage rate in an information processing system with respect to a maximum clock frequency attainable by the information processing system running the applications, for each of the applications based on the registered clock frequencies; and

determining the system clock frequency of the information processing system based on a total sum of calculated CPU usage rates for each of the applications, and recording a program for executing system clock frequency settings.

30. The recording medium according to claim 29, wherein when the determined system clock frequency exceeds the maximum clock frequency, a clock frequency excess alarm is sent.

31. The recording medium according to claim 30, wherein when the number of times that the system clock frequency exceeds the maximum clock frequency increases, an information processing system upgrade necessity alarm is activated.

32. The recording medium according to claim 29, wherein the clock frequency necessary for the running of the applications includes a first clock frequency at which the applications operate comfortably and a second clock frequency that is a minimum necessary for the applications to run, and when said information processing system is operating in a normal state, a first system clock frequency is determined based on the first clock frequency, while when the information processing system is operating in a specified state, a second system clock frequency is determined based on the second clock frequency, any one of the determined first and second system clock frequencies being set in the information processing system according to each state.

33. The recording medium according to claim 32, wherein the specified state is a case where a power source energy in said information processing system changes, and the second system clock frequency is set in the information processing system in place of the first system clock frequency according to a change in a detected remaining power source energy.

34. The recording medium according to claim 33, wherein an operation reservation time for said information processing system is set, and any one selected from among the first system clock frequency and the second system clock frequency is set in the information processing system such that an operation time calculated from the detected remaining power source energy is at least equal to the operation reservation time.

35. The recording medium according to claim 32, wherein said specified state is a case where a temperature in said information processing system changes, the system clock frequency is variable, and said system clock frequency is set in the information processing system, according to a change in a detected temperature.

36. The recording medium according to claim 35, wherein said second system clock frequency is set in said information processing system when the temperature is within a range in which erroneous operation of the information processing system occurs.

37. The recording medium according to claim 35, wherein said system clock frequency is increased by a predetermined width from the second system clock frequency and set as the system clock frequency in said information processing system when the temperature is close to the range in which erroneous operation of the information processing system occurs.

38. The recording medium according to claim 35, wherein said second system clock frequency is decreased by a predetermined width from the first system clock frequency and set as the system clock frequency in said information processing system when the temperature is far from a range in which erroneous operation of the information processing system occurs.

39. The recording medium according to claim 32, wherein said specified state is a case where external noise of said information processing system changes, the system clock frequency is variable, and the system clock frequency is set in the information processing system, according to a change in a detected external noise.

40. The recording medium according to claim 39, wherein, when information processing system noise level is within a permissible range with respect to an external noise level, the second system clock frequency is set in said information processing system.

41. The recording medium according to claim 39, wherein a permissible clock frequency corresponding to a noise level generated from said information processing system is prepared beforehand and, when a measured external noise level is higher than a noise level corresponding to the permissible noise clock frequency, the first system clock frequency is set in the information processing system.

42. The recording medium according to claim 39, wherein a permissible clock frequency corresponding to a noise level generated from said information processing system is prepared beforehand and, when a measured external noise level is lower than a noise level corresponding to the permissible noise clock frequency, the permissible clock frequency corresponding to the external noise level is set in the information processing system.