System, Method, and Computer Program Product for Conditionally Sending a Request for Data to a Node Based on a Determination

• US 20140040564A1
• Filed: 10/17/2013
• Published: 02/06/2014
• Est. Priority Date: 09/30/2009
• Status: Active Grant

• Current Assignee: Avago Technologies International Sales Pte Limited (Broadcom, Inc.)
• Original Assignee: Netlogic Microsystems Incorporated (Broadcom, Inc.)
• Inventors: Garg, Gaurav, Hass, David T.
• Granted Patent: US 9,465,739 B2
• Time in Patent Office: Days
• US Class Current: 711/141
• CPC Class Codes: G06F 12/0815 Cache consistency protocols
• CPC Class Codes: G06F 12/0831 using a bus scheme, e.g. with bus monitoring or watching means

Abstract

A system, method, and computer program product are provided for conditionally sending a request for data to a node based on a determination. In operation, a first request for data is sent to a cache of a first node. Additionally, it is determined whether the first request can be satisfied within the first node, where the determining includes at least one of determining a type of the first request and determining a state of the data in the cache. Furthermore, a second request for the data is conditionally sent to a second node, based on the determination.

Claims

1. A method, comprising:

sending a request for data to a cache of a first node;

receiving a response from the cache of the first node, wherein the response includes information relating to the state of the requested data; and

fulfilling the data request based on the state of the requested data.

2. The method of claim 1, further comprising determining whether the data is valid based on the state.

3. The method of claim 2, wherein fulfilling the data request comprises sending the request for data to a second node after determining that the that the data is not valid.

4. The method of claim 1, further comprising determining a type of the first request.

5. The method of claim 4, wherein fulfilling the data request is also based on the type of the first request.

6. The method of claim 4, wherein the type comprises read or write.

7. The method of claim 6, wherein fulfilling the data request comprises fulfilling the data request at the first node when the type is read.

8. The method of claim 6, wherein fulfilling the data request comprises fulfilling the data request comprises sending the request for data to a second node when the type is write.

9. The method of claim 1, wherein the information relating to the state of the requested data includes information about whether the data is locally shared or, globally shared.

10. The method of claim 9, wherein fulfilling the data request comprises fulfilling the data request at the first node when the data is locally shared and wherein fulfilling the data request comprises sending the request for data to a second node when the data is globally shared.

20. The node of claim 9, wherein the controller is configured to fulfill the data request by fulfilling the data request locally when the data is locally shared and wherein the controller is configured to fulfill the data request by sending the request for data to another node when the data is globally shared.

11. A node in a multiprocessor system, comprising:

a cache; and

a controller configured to;

send a request for data to the cache of the node;

receive a response from the cache of the first node, wherein the response includes information relating to the state of the requested data; and

fulfill the data request based on the state of the requested data.

12. The node of claim 11, wherein the controller is further configured to determine whether the data is valid based on the state.

13. The node of claim 12, the controller is configured to fulfill the data request by sending the request for data to a different node after determining that the that the data in the cache is not valid.

14. The node of claim 11, wherein the controller is further configured to determine a type of the request.

15. The node of claim 14, wherein the controller is further configured to fulfill the data request is also based on the type of the first request.

16. The node of claim 14, wherein the type comprises read or write.

17. The node of claim 16, wherein the controller is configured to fulfill the data request by fulfilling the data request locally node when the type is read.

18. The node of claim 16, wherein the controller is configured to fulfill the data request by sending the request for data to another node when the type is write.

19. The node of claim 11, wherein the information relating to the state of the requested data includes information about whether the data is locally shared or globally shared.