MULTIPROCESSING COMPUTING WITH DISTRIBUTED EMBEDDED SWITCHING

• US 20120120959A1
• Filed: 11/02/2009
• Published: 05/17/2012
• Est. Priority Date: 11/02/2009
• Status: Abandoned Application

• Current Assignee: Hewlett-Packard Development Company, L.P. (HP Inc.)
• Original Assignee: Hewlett-Packard Development Company, L.P. (HP Inc.)
• Inventors: Krause, Michael R
• Application Number:
  US13/386,649
• Publication Number:
  US 20120120959A1
• Time in Patent Office: Days
• US Class Current: 370/392
• CPC Class Codes: G06F 15/17381 Two dimensional, e.g. mesh, torus
• CPC Class Codes: H04L 12/4633 Interconnection of networks using encapsulation techniques, e.g. tunneling
• CPC Class Codes: H04L 49/25 Routing or path finding in a switch fabric
• CPC Class Codes: H04L 69/22 Parsing or analysis of headers

Abstract

A first one of multiple embedded processing elements (12-14) in a computer (10) receives a delivery packet (124) that is formatted in accordance with a delivery protocol and includes (i) an encapsulated payload packet (136) that is formatted in accordance with a payload protocol and (ii) a delivery packet header (134) including routing information. In response to a determination that it is not the destination for the delivery packet (124), the first processing element (14) sends the delivery packet (124) from the first processing element (14) to a second one of the processing elements based on the routing information. In response to a determination that it is the destination for the delivery packet (124), the first processing element (14) decapsulates the payload packet (136) from the delivery packet (124) and processes the decapsulated payload packet (136).

Claims

1. A method performed by embedded physical processing elements (12-14) in a computer (10), the method comprising at a first one of the processing elements (14):

receiving a delivery packet (124) that is formatted in accordance with a delivery protocol and comprises (i) an encapsulated payload packet (136) that is formatted in accordance with a payload protocol and (ii) a delivery packet header (134) comprising routing information;

determining from the routing information whether or not the delivery packet (124) is destined for the first processing element (14);

in response to a determination that the delivery packet (124) is not destined for the first processing element (14), sending the delivery packet (124) from the first processing element (14) to a second one of the processing elements based on the routing information; and

in response to a determination that the delivery packet (124) is destined for the first processing element (14), decapsulating the payload packet (136) from the delivery packet (124), and processing the decapsulated payload packet (136).

2. The method of claim 1, wherein the routing information comprises a destination address of one of the processing elements (22) to which the delivery packet (124) is destined, and the determining comprises determining whether or not the destination address matches an address of the first processing element (14).

3. The method of claim 2, wherein in response to a determination that the destination address fails to match the address of the first processing element (14),

applying the destination address as an input into a routing decision function for a first routing table (119) associated with the first processing element (14) to obtain an address of the second processing element, and

the sending comprises sending the delivery packet (124) to the address of the second processing element.

4. The method of any one of the preceding claims, wherein the routing information comprises a specification of a transmission route for the transmitting the delivery packet (124) across connected ones of the processing elements (12-14) from a source one of the processing elements (12) to a destination one of the processing s elements (22), and the determining comprises determining whether or not the first processing element (14) corresponds to a destination node on the transmission route.

5. The method of claim 4, wherein in response to a determination that the first processing element (14) does not correspond to the destination node on the transmission route, the sending comprises selecting a port of the first processing element (14) corresponding to a current node on the transmission route and sending the delivery packet (124) on a link out the selected port.

6. The method of any one of the preceding claims, further comprising:

at a second one of the processing elements, encapsulating the payload packet (136) into the delivery packet (124), wherein the encapsulating comprises obtaining routing information from a routing table (119) associated with the source processing element and encoding the routing information into the delivery packet header (134); and

transmitting the delivery packet (124) from the source processing element to the first processing element (14) based on the routing information.

7. The method of claim 6, wherein the encapsulating comprises obtaining from the routing table (119) a destination address of a destination one of the processing elements (22) to which the delivery packet (124) is destined and encoding the destination address into the delivery packet header (134);

and

further comprising obtaining from the routing table (119) a next hop address corresponding to the first processing element (14); and

wherein the transmitting comprises transmitting the delivery packet (124) to the next hop address.

8. The method of claim 6, wherein the encapsulating comprises obtaining from the routing table (119) a specification of a transmission route for the transmitting the delivery packet (124) across connected ones of the processing elements (12-22) from a source one of the processing elements (12) to a destination one of the processing elements (22), and encoding the transmission route into the delivery packet header (134) along with a pointer to a current recipient node on the transmission route.

9. The method of any one of the preceding claims, wherein the delivery packet (124) comprises an encoded identifier (138) of the payload protocol;

further comprising determining the payload protocol from the encoded identifier (138); and

wherein the decapsulating comprises decapsulating the payload packet (136) in accordance with the determined payload protocol and the processing comprises processing the decapsulated payload packet (136) as a payload protocol transaction.

10. The method of any one of the preceding claims, further comprising programming each of the processing elements (12-22) with a respective routing engine (117) and an associated routing table (119), wherein each of the routing engines is operable to perform the receiving, the determining, the sending, the decapsulating, and the processing.

11. The method of any one of the preceding claims, wherein the receiving comprises receiving the delivery packet (124) on a link (36) that directly connects the first processing element 14 to a respective other one of the processing elements (12) without any intervening discrete devices, and the sending comprises sending the delivery packet (124) to the second processing element on a link that is directly connected between the first and second processing elements.

12. The method of any one of the preceding claims, further comprising routing coherent transactions and non-coherent transactions from respective source ones of the processing elements to respective destination ones of the processing elements, wherein the routing comprises encapsulating each of the transactions into a respective delivery packet (124) that is formatted in accordance with the delivery protocol and includes a respective delivery packet header (134) that includes information for routing the delivery packet (124) between connected ones of the processing elements based on routing tables respectively associated with the processing elements (12-22).

13. The method of any one of the preceding claims, further comprising routing transactions between a first group (244) of the processing elements in a first coherency domain and a second group (246) of the processing elements in a second coherency domain, wherein the routing comprises encapsulating each of the transactions into a respective delivery packet (124) that is formatted in accordance with the delivery protocol and includes a respective delivery packet header (134) that includes information for routing the delivery packet (124) between connected ones of the processing elements based on routing tables respectively associated with the processing elements (12-22).

14. A computer, comprising embedded physical processing elements (12-14) including a first one of the processing elements (14) operable to perform operations comprising:

receiving a delivery packet (124) that is formatted in accordance with a delivery protocol and comprises (i) an encapsulated payload packet (136) that is formatted in accordance with a payload protocol and (ii) a delivery packet header (134) comprising routing information;

determining from the routing information whether or not the delivery packet (124) is destined for the first processing element (14);

in response to a determination that the delivery packet (124) is not destined for the first processing element (14), sending the delivery packet (124) from the first processing element (14) to a second one of the processing elements based on the routing information; and

in response to a determination that the delivery packet (124) is destined for the first processing element (14), decapsulating the payload packet (136) from the delivery packet (124), and processing the decapsulated payload packet (136).

15. The computer of claim 14, wherein in the receiving the first processing element (14) is operable to perform operations comprises receiving the delivery packet (124) on a link (36) that directly connects the first processing element 14 to a respective other one of the processing elements (12) without any intervening discrete devices, and the sending comprises sending the delivery packet (124) to the second processing element on a link that is directly connected between the first and second processing elements.

16. The computer of claim 14 or 15, wherein the processing elements (12-22) s are operable to perform operations comprising routing coherent transactions and non-coherent transactions from respective source ones of the processing elements to respective destination ones of the processing elements, wherein the routing comprises encapsulating each of the transactions into a respective delivery packet (124) that is formatted in accordance with the delivery protocol and includes a respective delivery packet header (134) that includes information for routing the delivery packet (124) between connected ones of the processing elements based on routing tables respectively associated with the processing elements (12-22).

17. The computer of any one of claims 14-16, wherein the processing elements (12-22) are operable to perform operations comprising routing transactions between a first group (244) of the processing elements in a first coherency domain and a second group (246) of the processing elements in a second coherency domain, wherein the routing comprises encapsulating each of the transactions into a respective delivery packet (124) that is formatted in accordance with the delivery protocol and includes a respective delivery packet header (134) that includes information for routing the delivery packet (124) between connected ones of the processing elements based on routing tables respectively associated with the processing elements (12-22).

18. The computer of any one of claims 14-17, wherein multiple of the processing elements are central processing units of the computer.

19. At least one computer-readable medium having computer-readable program code (121) embodied therein, the computer-readable program code (121) adapted to be executed by at least one of multiple embedded physical processing elements (12-14) of a computer to implement a method comprising at the first processing element (14):

receiving a delivery packet (124) that is formatted in accordance with a delivery protocol and comprises (i) an encapsulated payload packet (136) that is formatted in accordance with a payload protocol and (ii) a delivery packet header (134) comprising routing information;

determining from the routing information whether or not the delivery packet (124) is destined for the first processing element (14);

in response to a determination that the delivery packet (124) is not destined for the first processing element (14), sending the delivery packet (124) from the first processing element (14) to a second one of the processing elements based on the routing information; and

in response to a determination that the delivery packet (124) is destined for the first processing element (14), decapsulating the payload packet (136) from the delivery packet (124), and processing the decapsulated payload packet (136).

20. The at least one computer-readable medium of claim 19, wherein the method further comprises programming each of the processing elements (12-22) with a respective routing engine (117) and an associated routing table (119), wherein each of the routing engines is operable to perform the receiving, the determining, the sending, the decapsulating, and the processing.