Processor system with temperature sensor and control method of the same

• US 20060095911A1
• Filed: 02/23/2005
• Published: 05/04/2006
• Est. Priority Date: 11/04/2004
• Status: Active Grant

• Current Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Original Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Inventors: Nagai, Kenichi, Uemura, Goh
• Granted Patent: US 7,814,489 B2
• Time in Patent Office: Days
• US Class Current: 718/100
• CPC Class Codes: G06F 1/206 comprising thermal management
• 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 9/5027 the resource being a machine, e.g. CPUs, Servers, Terminals
• CPC Class Codes: G06F 9/5094 where the allocation takes into account power or heat criteria power management in computers in general G06F1/3203; thermal management in computers in general G06F1/206
• CPC Class Codes: Y02D 10/00 Energy efficient computing, e.g. low power processors, power management or thermal management

Abstract

A processor system includes a plurality of first processors, a temperature sensor, a main memory, and a second processor. The first processors individually process tasks. The temperature sensor measures a temperature of each of the first processors. The main memory stores programs of the tasks processed by the first processors, and a task priority order table containing a relationship between the tasks and task priority numbers. The second processor assigns the tasks to the first processors on the basis of the task priority order table and the temperatures of the first processors measured by the temperature sensor.

Claims

1. A processor system comprising:

a plurality of first processors which individually process tasks;

a temperature sensor which measures a temperature of each of the first processors;

a main memory which stores programs of the tasks processed by the first processors, and a task priority order table containing a relationship between the tasks and task priority numbers; and

a second processor which assigns the tasks to the first processors on the basis of the task priority order table and the temperatures of the first processors measured by the temperature sensor.

2. The system according to claim 1, wherein the second processor expects a temperature, to which each of the first processors would reach after a unit time for executing one process,

when the expected temperature exceeds a predetermined temperature, the second processor saves the task assigned to the first processor, and stops an operation of the first processor.

3. The system according to claim 2, wherein the predetermined temperature is an upper limit temperature at which the operation of the first processor is allowed,

the main memory further stores:

a first temperature data table containing first data on the upper-limit temperature of each of the first processors;

a second temperature data table containing second data on an increase in temperature of the first processor when the task is processed;

a third temperature data table containing third data on a drop in temperature of the first processor, the drop in temperature being proportional to a free time occurring after processing the task within the unit time; and

a fourth temperature data table containing fourth data on the expected temperature of the first processor; and

the second processor calculates the expected temperature using the current temperature obtained from the temperature sensor, the second data obtained from the second temperature data table, third data obtained from the third temperature data table, stores the calculated expected temperature in the fourth temperature data table, and compares the expected temperature and the upper-limit temperature.

4. The system according to claim 2, wherein the second processor monitors the temperature sensor;

when any one of the first processors reached the predetermined temperature while the task is being processed, the second processor saves the task in the main memory, and stops the operation of the first processor; and

the main memory includes a context save area in which information relating to the saved task is to be stored.

5. The system according to claim 1, wherein the second processor expects a temperature, to which each of the first processors would reach after a unit time for executing one process,

the second processor assigns the task to only the processor, the expected temperature of which does not exceed a predetermined temperature.

6. The system according to claim 5, wherein the predetermined temperature is an upper limit temperature at which the operation of the first processor is allowed,

the main memory further stores:

a first temperature data table containing first data on the upper-limit temperature of each of the first processors;

a second temperature data table containing second data on an increase in temperature of the first processor when the task is processed;

a third temperature data table containing third data on a drop in temperature of the first processor, the drop in temperature being proportional to a free time occurring after processing the task within the unit time; and

a fourth temperature data table containing fourth data on the expected temperature of the first processor; and

the second processor calculates the expected temperature using the current temperature obtained from the temperature sensor, the second data obtained from the second temperature data table, third data obtained from the third temperature data table, stores the calculated expected temperature in the fourth temperature data table, and compares the expected temperature and the upper-limit temperature.

7. The system according to claim 5, wherein the second processor monitors the temperature sensor;

when any one of the first processors reached the predetermined temperature while the task is being processed, the second processor saves the task in the main memory, and stops the operation of the first processor; and

the main memory includes a context save area in which information relating to the saved task is to be stored.

8. The system according to claim 1, wherein the main memory further stores a task assignment table containing information on correspondency between the first processors and the tasks assigned to each first processor,

the second processor updates the task assignment table such that a task with a highest priority number in the task priority order table is assigned to the first processor with a lowest temperature, and assigns the tasks to the first processors in accordance with information in the task assignment table.

9. The system according to claim 3, wherein the main memory further stores a fifth temperature data table containing fifth data on an increase in temperature of the first processor due to heat propagation from the other adjacent first processor,

the second processor calculates the expected temperature by adding the third and fifth data to the current temperature, and subtracting the third data

10. A control method of a processor system having a plurality of processors, comprising:

measuring temperatures of the plurality of processors;

assigning tasks to the processors in accordance with a process priority order and the temperatures of the processors;

expecting a temperature to which the temperature of each processor would reach after a unit time for executing one process;

causing the processor, the expected temperature exceeds a predetermined temperature, to save the task assigned to the processor to a main memory;

causing the processor, the expected temperature of which does not exceed the predetermined temperature, to process the assigned task.

11. The method according to claim 10, wherein the task with a highest priority number in a task priority order table is assigned to the processor with the lowest measured temperature.

12. The method according to claim 10, further comprising re-assigning, when the task with a high priority number is saved, the task to any one of the other processors.

13. The method according to claim 10, further comprising:

saving the task, which is being processed by any one of the processors, to the main memory if the temperature of the any one of the processors reaches the predetermined temperature in execution of the task;

stopping the operation of the processor, a temperature of which reaches the predetermined temperature; and

re-assigning the task, which is saved, to any one of the other processors.

14. The method according to claim 13, wherein when the task is saved to the main memory, contents of a register and a memory, which are provided in the processor, are stored in the main memory, whereby a state of the processor is saved, and

when the task is re-assigned to the any one of the other processors, the state of the processor, which is stored by saving the task, is read out of the main memory, whereby the any one of the other processors is caused to resume the task.

15. The method according to claim 10, wherein the expecting the temperature includes:

adding the current temperature and a first temperature by which the temperature of the processor rise when the processor executes the task;

subtracting a second temperature, by which the temperature of the processor drops and which is obtained on the basis of a free time within the unit time, from an added result of the current temperature and the first temperature;

wherein a subtraction result obtained by subtracting the second temperature from the added result is set as the expected temperature.

16. A control method of a processor system having a plurality of processors, comprising:

measuring temperatures of the plurality of processors;

determining tasks that are to be assigned to the processors in accordance with a process priority order and the temperatures of the processors;

expecting a temperature to which the temperature of each processor would reach after a unit time for executing one process;

assigning no task to the processor, the expected temperature of which exceeds a predetermined temperature, and assigning the task to the processor, the expected temperature of which does not exceed the predetermined temperature; and

causing the processor, to which the task is assigned, to process the task.

17. The method according to claim 16, wherein the task with a highest priority number is assigned to the processor with the lowest measured temperature.

18. The method according to claim 16, further comprising:

saving the task, which is being processed by any one of the processors, to the main memory if the temperature of the any one of the processors reaches the predetermined temperature in execution of the task;

stopping the operation of the processor,

a temperature of which reaches the predetermined temperature; and

re-assigning the task, which is saved, to any one of the other processors.

19. The method according to claim 18, wherein when the task is saved to the main memory, contents of a register and a memory, which are provided in the processor, are stored in the main memory, whereby a state of the processor is saved, and

when the task is re-assigned to the any one of the other processors, the state of the processor, which is stored by saving the task, is read out of the main memory, whereby the any one of the other processors is caused to resume the task.

20. The method according to claim 16, wherein the expecting the temperature includes:

adding the current temperature and a first temperature by which the temperature of the processor rise when the processor executes the task;

subtracting a second temperature, by which the temperature of the processor drops and which is obtained on the basis of a free time within the unit time, from an added result of the current temperature and the first temperature;

wherein a subtraction result obtained by subtracting the second temperature from the added result is set as the expected temperature.