Apparatus and methods for dynamic reallocation of virtual lane buffer space in an infiniband switch

• US 7,209,478 B2
• Filed: 05/31/2002
• Issued: 04/24/2007
• Est. Priority Date: 05/31/2002
• Status: Active Grant

• Current Assignee: Microsemi Solutions (U.S.), Inc. (Microchip Technology Incorporated)
• Original Assignee: Palau Acquisition Corporation
• Inventors: Rojas, Edmundo, Tucker, S. Paul
• Primary Examiner(s): Chan; Wing
• Assistant Examiner(s): NGO, NGUYEN HOANG
• Application Number:
  US10/160,938
• Publication Number:
  US 20030223416A1
• Time in Patent Office: 1,789 Days
• Field of Search: 370/351, 370/357, 370/358, 370/359, 370/360, 370/389, 370/412, 370/413, 370/419, 370/390
• US Class Current: 370/360
• CPC Class Codes: H04L 49/101 using crossbar or matrix
• CPC Class Codes: H04L 49/201 Multicast operation; Broadcast operation
• CPC Class Codes: H04L 49/25 Routing or path finding in a switch fabric
• CPC Class Codes: H04L 49/254 Centralised controller, i.e. arbitration or scheduling
• CPC Class Codes: H04L 49/3018 Input queuing
• CPC Class Codes: H04L 49/358 Infiniband Switches
• CPC Class Codes: H04L 49/90 Buffering arrangements

Abstract

A switch for use with an InfiniBand network. The switch includes a crossbar that redirects packet-based data based on a forwarding table. At least one port that receives data from a network and selectively transfers that data to the crossbar using a variable number of virtual lanes. A state machine controls the changing of the number of virtual lanes.

Claims

1. A switch for use with an InfiniBand network, the switch comprising:

a crossbar that redirects packet-based data;

at least one port that receives the packet-based data from a network and selectively transfers the packet-based data to the crossbar over a dynamically variable number of virtual lanes allocated within a buffer; and

a state machine that controls dynamic variation of the number of virtual lanes during active transmission and reception of the packet-based data;

wherein the state machine adds virtual lanes by monitoring existing virtual lanes and resizing the existing virtual lanes when the amount of data in each existing virtual lane is less than the required size for the resized lane; and

creating a new virtual lane using the space created by the resizing; and

wherein the state machine further monitors the amount of time that has been spent monitoring existing virtual lanes and upon the expiration of a predetermined amount of time, resizes the existing virtual lanes.

2. The switch, as set forth in claim 1, wherein the state machine is configured to reallocate space within the buffer to accommodate dynamic variation of the number of virtual lanes.

3. A switch for use with an InfiniBand network, the switch comprising:

a crossbar that redirects packet-based data;

at least one port that receives the packet-based data from a network and selectively transfers the packet-based data to the crossbar over a dynamically variable number of virtual lanes allocated within a buffer; and

a state machine that controls dynamic variation of the number of virtual lanes during active transmission and reception of the packet-based data;

wherein the state machine deletes virtual lanes by monitoring existing virtual lanes and, when a virtual lane is identified as being empty and idle, disabling the empty and idle virtual lane and resizing the remaining virtual lanes; and

wherein the state machine further monitors the amount of time that has been spent monitoring existing virtual lanes and upon the expiration of a predetermined amount of time, disables a virtual lane.

4. A method for reconfiguring the number of virtual lanes within an Infiniband switch, the method comprising:

determining, during active transmission or reception of data packets, that the number of virtual lanes within the switch requires adjustment;

dynamically reallocating buffer space to add a virtual lane by monitoring existing virtual lanes and monitoring the amount of time that has been spent monitoring existing virtual lanes, resizing the existing virtual lanes upon the expiration of a predetermined amount of time and when the amount of data in each existing virtual lane is less than the required size for the resized lane, and creating a new virtual lane using the space created by the resizing.

5. The method of claim 4, wherein the step of determining comprises receiving a subnet management packet (SMP).

6. The method of claim 4, wherein the step of determining comprises receiving an OperationalVL attribute.

7. The method of claim 6, wherein the steps of identifying and resizing are repeated for each existing virtual lane.

8. The method of claim 4, wherein dynamically reallocating buffer space to add a virtual lane comprises:

identifying an idle virtual lane;

resizing the idle virtual lane to a predetermined new virtual lane size, thereby freeing up buffer space to add the virtual lane; and

adding the virtual lane.

9. The method of claim 4, wherein dynamically reallocating buffer space to delete a virtual lane comprises:

identifying an idle virtual lane;

disabling the idle virtual lane, thereby freeing up buffer space; and

reallocating the buffer space associated with the idle virtual lane amongst enabled virtual lanes.

10. A method for reconfiguring the number of virtual lanes within an Infiniband switch, the method comprising:

determining, during active transmission or reception of data packets, that the number of virtual lanes within the switch requires adjustment;

dynamically reallocating buffer space to delete a virtual lane by monitoring existing virtual lanes and monitoring the amount of time that has been spent monitoring existing virtual lanes;

identifying a virtual lane as being empty and idle and, upon expiration of a predetermined amount of time, disabling the empty and idle virtual lane; and

resizing the remaining virtual lanes.