System and Method for Providing Multiple Redundant Direct Routes Between Supernodes of a Multi-Tiered Full-Graph Interconnect Architecture

• US 20090063444A1
• Filed: 08/27/2007
• Published: 03/05/2009
• Est. Priority Date: 08/27/2007
• Status: Active Grant

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: Arimilli, Ravi K., Rajamony, Ramakrishnan, Arimilli, Lakshminarayana B.
• Granted Patent: US 7,769,891 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: G06F 15/17381 Two dimensional, e.g. mesh, torus
• CPC Class Codes: H04L 67/63 Routing a service request depending on the request content or context

Abstract

A method, computer program product, and system are provided for selecting, from a plurality of routes through the data processing system, a direct route for transmitting data. Data that includes address information is received at a first processor that is to be transmitted to a destination processor. Using routing table data structures, direct route entries are identified that correspond to direct routes for transmitting data. An accessed priority table data structure comprises a priority entry for each entry in the routing table data structures. The priority entry specifies a priority of a corresponding entry in the routing table data structures. A direct route entry is selected that corresponds to a direct route from the routing table data structures, based on specified priorities. Then the data is transmitted from the first processor to the destination processor using a path corresponding to the selected direct route entry.

Claims

1. A method, in a data processing system, for selecting, from a plurality of routes through the data processing system, a direct route for transmitting data, the method comprising:

receiving data at a first processor within a set of processors that is to be transmitted to a destination processor, wherein the data includes address information;

identifying, in one or more routing table data structures, direct route entries corresponding to a plurality of direct routes for transmitting data from a first processor to a destination processor;

accessing a priority table data structure associated with the one or more routing table data structures, wherein the priority table data structure comprises a priority entry for each entry in the one or more routing table data structures, the priority entry specifying a priority of a corresponding entry in the one or more routing table data structures;

selecting a direct route entry corresponding to a direct route in the plurality of direct routes from the one or more routing table data structures, based on specified priorities in priority entries of the priority table data structure corresponding to the direct route entries of the plurality of direct routes; and

transmitting the data from the first processor to the destination processor using a path corresponding to the selected direct route entry.

2. The method of claim 1, wherein the one or more routing table data structures comprise an entry for each route in the plurality of routes, and wherein the plurality of routes comprises the plurality of direct routes and at least one indirect route.

3. The method of claim 1, wherein the entries in the one or more routing table data structures comprise a pointer field that stores a pointer to a priority entry in the priority table data structure corresponding to the entry in the one or more routing table data structures, and wherein accessing the priority table data structure comprises using a pointer in a first direct route entry to identify a corresponding priority entry in the priority table data structure.

4. The method of claim 3, wherein the entries in the one or more routing table data structures comprise a last used field that identifies whether an entry in the one or more routing table data structures was previously used to route data.

5. The method of claim 4, wherein the first direct route entry used to identify a corresponding priority entry in the priority table data structure is a direct route entry in the direct route entries whose last used field identifies the direct route entry as having been previously used to route data.

6. The method of claim 3, wherein selecting the direct route entry comprises:

identifying a next priority entry in the priority table data structure having a next higher priority ranking from the priority entry corresponding to the first direct route entry;

identifying a direct route entry in the direct route entries corresponding to the next priority entry; and

selecting the identified direct route entry corresponding to the next priority entry as the direct route entry whose path is used to transmit the data.

7. The method of claim 1, wherein the priority entries are assigned by at least one of a random selection, an adaptive real-time selection, a round-robin selection, or a selection that is identified with the data.

8. The method of claim 1, wherein the direct route for transmitting the data is determined by at least one of software, hardware, a combination of software and hardware, or determined by an administrator.

9. The method of claim 1, wherein the method is implemented by a switch integrated in the first processor.

10. A computer program product for selecting, from a plurality of routes through the data processing system, a direct route for transmitting data, comprising a computer useable medium having a computer readable program, wherein the computer readable program, when executed in a first processor in a set of processors of a data processing system, causes the first processor to:

receive data that is to be transmitted to a destination processor, wherein the data includes address information;

identify, in one or more routing table data structures, direct route entries corresponding to a plurality of direct routes for transmitting data from a first processor to a destination processor;

access a priority table data structure associated with the one or more routing table data structures, wherein the priority table data structure comprises a priority entry for each entry in the one or more routing table data structures, the priority entry specifying a priority of a corresponding entry in the one or more routing table data structures;

select a direct route entry corresponding to a direct route in the plurality of direct routes from the one or more routing table data structures, based on specified priorities in priority entries of the priority table data structure corresponding to the direct route entries of the plurality of direct routes; and

transmit the data from the first processor to the destination processor using a path corresponding to the selected direct route entry.

11. The computer program product of claim 10, wherein the one or more routing table data structures comprise an entry for each route in the plurality of routes, and wherein the plurality of routes comprises the plurality of direct routes and at least one indirect route.

12. The computer program product of claim 10, wherein the entries in the one or more routing table data structures comprise a pointer field that stores a pointer to a priority entry in the priority table data structure corresponding to the entry in the one or more routing table data structures, and wherein accessing the priority table data structure comprises using a pointer in a first direct route entry to identify a corresponding priority entry in the priority table data structure.

13. The computer program product of claim 12, wherein the entries in the one or more routing table data structures comprise a last used field that identifies whether an entry in the one or more routing table data structures was previously used to route data.

14. The computer program product of claim 13, wherein the first direct route entry used to identify a corresponding priority entry in the priority table data structure is a direct route entry in the direct route entries whose last used field identifies the direct route entry as having been previously used to route data.

15. The computer program product of claim 12, wherein the computer readable program further causes the first processor to:

identify a next priority entry in the priority table data structure having a next higher priority ranking from the priority entry corresponding to the first direct route entry;

identify a direct route entry in the direct route entries corresponding to the next priority entry; and

select the identified direct route entry corresponding to the next priority entry as the direct route entry whose path is used to transmit the data.

16. The computer program product of claim 10, wherein the computer readable program is executed in a switch integrated in the first processor.

17. A data processing system for selecting, from a plurality of routes through the data processing system, a direct route for transmitting data, comprising:

a set of processors; and

a memory coupled to the set of processors, wherein the memory comprises instructions which, when executed by a first processor in the set of processors, cause the first processor to;

receive data that is to be transmitted to a destination processor, wherein the data includes address information;

identify, in one or more routing table data structures, direct route entries corresponding to a plurality of direct routes for transmitting data from a first processor to a destination processor;

access a priority table data structure associated with the one or more routing table data structures, wherein the priority table data structure comprises a priority entry for each entry in the one or more routing table data structures, the priority entry specifying a priority of a corresponding entry in the one or more routing table data structures;

select a direct route entry corresponding to a direct route in the plurality of direct routes from the one or more routing table data structures, based on specified priorities in priority entries of the priority table data structure corresponding to the direct route entries of the plurality of direct routes; and

transmit the data from the first processor to the destination processor using a path corresponding to the selected direct route entry.

18. The system of claim 17, wherein the one or more routing table data structures comprise an entry for each route in the plurality of routes, and wherein the plurality of routes comprises the plurality of direct routes and at least one indirect route.

19. The system of claim 17, wherein the entries in the one or more routing table data structures comprise a pointer field that stores a pointer to a priority entry in the priority table data structure corresponding to the entry in the one or more routing table data structures, and wherein accessing the priority table data structure comprises using a pointer in a first direct route entry to identify a corresponding priority entry in the priority table data structure.

20. The system of claim 19, wherein the entries in the one or more routing table data structures comprise a last used field that identifies whether an entry in the one or more routing table data structures was previously used to route data, and wherein the first direct route entry used to identify a corresponding priority entry in the priority table data structure is a direct route entry in the direct route entries whose last used field identifies the direct route entry as having been previously used to route data.