Thread Selection During Context Switching On A Plurality Of Compute Nodes

• US 20130179897A1
• Filed: 03/04/2013
• Published: 07/11/2013
• Est. Priority Date: 06/09/2008
• Status: Active Grant

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: Archer, Charles J., Blocksome, Michael A., Ratterman, Joseph D., Smith, Brian E., Randles, Amanda E.
• Granted Patent: US 9,459,917 B2
• Time in Patent Office: Days
• US Class Current: 718/108
• 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 2209/5018 Thread allocation
• CPC Class Codes: G06F 9/46 Multiprogramming arrangements
• CPC Class Codes: G06F 9/48 Program initiating; Program switching, e.g. by interrupt
• CPC Class Codes: G06F 9/4893 taking 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: 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

Methods, apparatus, and products are disclosed for thread selection during context switching on a plurality of compute nodes that includes: executing, by a compute node, an application using a plurality of threads of execution, including executing one or more of the threads of execution; selecting, by the compute node from a plurality of available threads of execution for the application, a next thread of execution in dependence upon power characteristics for each of the available threads; determining, by the compute node, whether criteria for a thread context switch are satisfied; and performing, by the compute node, the thread context switch if the criteria for a thread context switch are satisfied, including executing the next thread of execution.

Claims

1. A method of thread selection for context switching on a plurality of compute nodes, the method comprising:

executing, by a compute node of the plurality of compute nodes, an application using a plurality of threads of execution, including executing one or more of the threads of execution;

predefining power characteristics of each thread available for execution of an application;

selecting, by the compute node from a plurality of available threads of execution for the application, a next thread of execution in dependence upon power characteristics for each of the available threads by determining a current power mode for the compute node while executing a thread of the application, and selecting, from the available threads of execution, the next thread of execution having predefined power characteristics that are consistent with the current power mode; and

executing the selected next thread.

2. The method of claim 1 wherein the next thread of execution is a software thread.

3. The method of claim 1 wherein the next thread of execution is a hardware thread in a Symmetric Multi-Processing (‘

SMP’

) architecture.

5. The method claim 1 wherein selecting, from the available threads of execution, the next thread of execution having predefined power characteristics that are consistent with the current power mode further comprises selecting the next thread according to a power mode switching algorithm.

6. The method claim 1 wherein selecting, from the available threads of execution, the next thread of execution having predefined power characteristics that are consistent with the current power mode further comprises selecting the next thread according to external operating conditions for the compute node.

7. The method claim 1 wherein the plurality of compute nodes are connected together for data communications using a plurality of data communications networks, at least one of the data communications networks optimized for point to point operations, and at least one of the data communications networks optimized for collective operations.

4. (canceled)

8. A parallel computer capable of thread selection for context switching on a plurality of compute nodes, the parallel computer comprising the plurality of compute nodes, each of the compute nodes comprising one or more computer processors and computer memory operatively coupled to the computer processors, the computer memory having disposed within it computer program instructions capable of:

executing, by a compute node of the plurality of compute nodes, an application using a plurality of threads of execution, including executing one or more of the threads of execution;

predefining power characteristics of each thread available for execution of an application;

selecting, by the compute node from a plurality of available threads of execution for the application, a next thread of execution in dependence upon power characteristics for each of the available threads by determining a current power mode for the compute node while executing a thread of the application, and selecting, from the available threads of execution, the next thread of execution having predefined power characteristics that are consistent with the current power mode; and

executing the selected next thread.

10. The parallel computer claim 8 wherein selecting, from the available threads of execution, the next thread of execution having predefined power characteristics that are consistent with the current power mode further comprises selecting the next thread according to a power mode switching algorithm.

11. The parallel computer claim 8 wherein selecting, from the available threads of execution, the next thread of execution having predefined power characteristics that are consistent with the current power mode further comprises selecting the next thread according to external operating conditions for the compute node.

9. (canceled)

12. A computer program product for thread selection for context switching on a plurality of compute nodes, the computer program product disposed upon a computer readable recordable medium, the computer program product comprising computer program instructions capable of:

executing, by a compute node of the plurality of compute nodes, an application using a plurality of threads of execution, including executing one or more of the threads of execution;

predefining power characteristics of each thread available for execution of an application;

selecting, by the compute node from a plurality of available threads of execution for the application, a next thread of execution in dependence upon power characteristics for each of the available threads by determining a current power mode for the compute node while executing a thread of the application, and selecting, from the available threads of execution, the next thread of execution having predefined power characteristics that are consistent with the current power mode; and

executing the selected next thread.

13. The computer program product of claim 12 wherein the next thread of execution is a software thread.

14. The computer program product of claim 12 wherein the next thread of execution is a hardware thread in a Symmetric Multi-Processing (‘

SMP’

) architecture.

16. The computer program product of claim 12 wherein selecting, from the available threads of execution, the next thread of execution having predefined power characteristics that are consistent with the current power mode further comprises selecting the next thread according to a power mode switching algorithm.

17. The computer program product of claim 12 wherein selecting, from the available threads of execution, the next thread of execution having predefined power characteristics that are consistent with the current power mode further comprises selecting the next thread according to external operating conditions for the compute node.

18. The computer program product of claim 12 wherein the plurality of compute nodes are connected together for data communications using a plurality of data communications networks, at least one of the data communications networks optimized for point to point operations, and at least one of the data communications networks optimized for collective operations.

15. (canceled)

19. (canceled)

20. (canceled)