TCP offload send optimization

• US 9,413,788 B1
• Filed: 12/17/2012
• Issued: 08/09/2016
• 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): Cox, Natisha
• Application Number:
  US13/716,635
• Time in Patent Office: 1,331 Days
• Field of Search: None
• US Class Current: 1/1
• 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 and a corresponding driver;

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

providing, by the driver to the network interface, a series of commands to transmit data from the application by the network interface, wherein a plurality of commands of the series of commands together denote an amount of the data that is less than the amount denoted by one commands of the series of commands;

providing, by the network interface to the driver, a notification that the one command of the series of commands has been completed by the network interface, and

providing, by the network interface to the driver, a single notification that the plurality of commands of the series of commands have been completed by the network interface.

2. The method of claim 1, further comprising setting, at the network interface, a SndUna threshold for the TCP connections, wherein a SndUna value that is greater than or equal to the SndUna threshold initiates one of the notifications.

3. The method of claim 2, wherein the SndUna threshold has a sequence number that is within one sequence number of an ending sequence number of the data denoted by the one command of the series of commands.

4. The method of claim 2, wherein providing the single notification that the plurality of commands of the series of commands have been completed is triggered by receiving, by the network interface, an acknowledgement (ACK) having a sequence number greater than or equal to the SndUna threshold.

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

6. The method of claim 2, further comprising calculating, by the computer, the SndUna threshold.

7. The method of claim 1, wherein:

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 of the series of commands.

8. The method of claim 1, further comprising:

providing, by the computer to the network interface, a SndUna threshold, prior to providing, by the network interface to the computer, a SndUna value that serves as one of the notifications; and

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

9. The method of claim 1, further comprising providing, by the computer to the network interface, a SndUna threshold having a sequence number equal to the ending sequence number of data denoted by a first command of the plurality of commands of the series of commands.

10. The method of claim 1, wherein providing the single notification that the plurality of the commands have been completed is in response to receiving, by the network interface, an acknowledgement (ACK) for all data denoted by the plurality of the commands.

11. The method of claim 1, wherein providing the single notification that the plurality of commands of the series of commands have been completed includes providing, by the network interface to the computer, a SndUna value of the TCP connections.

12. The method of claim 11, further comprising:

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

13. The method of claim 1, wherein providing the notification that the one command of the series of commands has been completed includes providing, by the network interface to the computer, a SndUna value of the TCP connections.

14. The method of claim 13, 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 denoted by the one command.

15. A method comprising:

running an application on a computer having a network interface and a corresponding driver, 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 to the driver a command to send data from the application;

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

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

otherwise, providing a SndUna threshold from the computer to the network interface, the SndUna threshold being equal to or one sequence number greater than an ending sequence number of a first command to send data that is outstanding at the network interface.