TCP offload send optimization

• US 8,341,286 B1
• Filed: 07/16/2009
• Issued: 12/25/2012
• Est. Priority Date: 07/31/2008
• Status: Active Grant

• Current Assignee: Alacritech, Inc.
• Original Assignee: Alacritech, Inc.
• Inventors: Craft, Peter K., Philbrick, Clive M., Starr, Daryl D.
• Primary Examiner(s): BILGRAMI, ASGHAR H
• Application Number:
  US12/504,021
• Time in Patent Office: 1,258 Days
• Field of Search: 709/232, 370/229
• US Class Current: 709/232
• CPC Class Codes: H04L 65/1013 Network architectures, gateways, control or user entities
• CPC Class Codes: H04L 67/025 for remote control or remote monitoring of applications
• CPC Class Codes: H04L 67/141 Setup of application sessions admission control or resource allocation in data switching networks H04L47/70
• CPC Class Codes: H04L 69/161 Implementation details of TCP/IP or UDP/IP stack architecture; Specification of modified or new header fields
• CPC Class Codes: H04L 69/163 In-band adaptation of TCP data exchange; In-band control procedures
• CPC Class Codes: H04L 69/32 Architecture of open systems interconnection [OSI] 7-layer type protocol stacks, e.g. the interfaces between the data link level and the physical level

Abstract

A host with a network interface that offloads a TCP connection is disclosed in which the notification that relatively small data transmit commands have completed is batched whereas the notification that relatively large data transmit commands have completed are not batched. The notification that data transmit commands have completed may be intrinsically modulated by the size and frequency of the commands and the processing of the data transfer by the TCP connection. One embodiment involves a method comprising: running an application on a computer having a network interface; running, on the network interface, a TCP connection for the application; providing, by the computer to the network interface, a command to send data from the application; updating, by the network interface, a SndUna value for the TCP connection; and providing, by the network interface to the computer, the SndUna value, thereby indicating to the computer that the command has been completed.

Claims

1. A method comprising:

running an application on a computer having a network interface, the application controlling data;

running, on the network interface, a transmission control protocol (TCP) connection for the application, including maintaining a SndUna value for the TCP connection;

providing, by the computer to the network interface, a command to send the data;

setting a SndUna threshold at the network interface, the SndUna threshold having a sequence number that is greater than or equal to the ending sequence number of the data;

updating, by the network interface, the SndUna value; and

providing, by the network interface to the computer, the SndUna value, thereby indicating to the computer that the command has been completed;

wherein providing the SndUna value is initiated by receiving, by the network interface, an acknowledgement having a sequence number greater than or equal to the SndUna threshold.

2. The method of claim 1, further comprising providing, by the computer to the network interface, the SndUna threshold.

3. The method of claim 1, further comprising calculating, by the computer, the SndUna threshold.

5. The method of claim 1, further comprising:

providing, by the computer to the network interface, the SndUna threshold, prior to providing, by the network interface to the computer, the SndUna value;

checking, by the computer, that the SndUna value has a sequence number greater than or equal to the SndUna threshold.

6. The method of claim 1, further comprising:

checking, by the computer, that the SndUna value has a sequence number greater than or equal to the ending sequence number of the data.

7. The method of claim 1, wherein plural commands to send data for the application are outstanding at the network interface, and the SndUna threshold has a sequence number equal to the ending sequence number of data of the first outstanding command.

8. The method of claim 1, wherein providing the SndUna value is triggered by receiving, by the network interface, an acknowledgement for all outstanding data.

4. A method comprising:

running an application on a computer having a network interface, the application controlling data;

running, on the network interface, a transmission control protocol (TCP) connection for the application, including maintaining a SndUna value for the TCP connection;

providing, by the computer to the network interface, a command to send the data;

updating, by the network interface, the SndUna value; and

providing, by the network interface to the computer, the SndUna value, thereby indicating to the computer that the command has been completed;

if a second command to send data is not outstanding at the network interface, a SndUna threshold is not provided from the computer to the network interface;

otherwise, if a SndUna threshold is outstanding on the network interface, a second SndUna threshold is not provided from the computer to the network interface; and

otherwise, a SndUna threshold is provided from the computer to the network interface, the SndUna threshold set to an ending sequence number of a first command to send data that is outstanding at the network interface.

9. A method comprising:

running, on a network interface for a computer, a transmission control protocol (TCP) connection for an application, including maintaining a SndUna value for the TCP connection;

setting a SndUna threshold at the network interface; and

providing the SndUna value to the computer when the SndUna value is greater than or equal to the SndUna threshold.

10. The method of claim 9, wherein providing the SndUna value to the computer indicates that a command to send data for the application has been completed.

11. The method of claim 9, further comprising providing the SndUna threshold by the computer to the network interface.

12. The method of claim 9, wherein providing the SndUna value is triggered by receiving, by the network interface, an acknowledgement for all outstanding data.

13. The method of claim 9, wherein providing the SndUna value is triggered by receiving, by the network interface, an acknowledgement having a sequence number greater than or equal to the SndUna threshold.

14. The method of claim 9, wherein setting the SndUna threshold includes setting the SndUna threshold to a sequence number that is equal to or one sequence number greater than the ending sequence number of the data.

15. The method of claim 9, further comprising calculating, by the computer, the SndUna threshold.

16. The method of claim 9, further comprising:

checking, by the computer, that the SndUna value has a sequence number greater than or equal to the SndUna threshold.

17. The method of claim 9, further comprising:

checking, by the computer, that the SndUna value has a sequence number greater than or equal to the ending sequence number of the data.

18. The method of claim 9, further comprising:

providing, by the computer to the network interface, a plurality of commands to send data for the application, wherein the SndUna threshold has a sequence number equal to or one sequence number greater than the ending sequence number of the data of the first outstanding command.

19. A method comprising:

running, on a network interface for a computer, a transmission control protocol (TCP) connection for an application, including maintaining an interface sequence number;

providing, by the computer to the network interface, a command to send data for the TCP connection;

storing, by the computer, an ending sequence number for the data corresponding to the command;

determining an offset between the ending sequence number and the interface sequence number;

setting, at the network interface, a threshold sequence number; and

notifying the computer, by the network interface, that the command has been completed by providing to the computer the interface sequence number when the interface sequence number is greater than or equal to the threshold sequence number.

20. The method of claim 19, further comprising providing, by the computer to the network interface, the threshold sequence number, prior to providing to the computer the interface sequence number or the ending sequence number.

21. The method of claim 19, wherein providing to the computer the interface sequence number or the ending sequence number includes providing to the computer the SndUna value.