Efficient send socket call handling by a transport layer

• US 20070133582A1
• Filed: 12/12/2005
• Published: 06/14/2007
• Est. Priority Date: 12/12/2005
• Status: Active Grant

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: Venkatsubra, Venkat, Jain, Vinit, Banerjee, Dwip, Ramalingam, Kavitha
• Granted Patent: US 7,571,247 B2
• Time in Patent Office: Days
• US Class Current: 370/412
• CPC Class Codes: H04L 47/10 Flow control; Congestion control
• CPC Class Codes: H04L 47/266 Stopping or restarting the source, e.g. X-on or X-off
• CPC Class Codes: H04L 47/30 in combination with information about buffer occupancy at either end or at transit nodes
• CPC Class Codes: H04L 49/90 Buffering arrangements
• CPC Class Codes: H04L 49/901 using storage descriptor, e.g. read or write pointers

Abstract

A method, system, and program provide for efficient send socket call handling by a transport layer. A transport layer of a network protocol stack receives a send socket call for data of a specified length from an application layer. Responsive to detecting that there is insufficient memory for a single memory allocation to a buffer in the transport layer for at least the specified length, the transport layer blocks the send socket call. The transport layer only wakes the send socket call upon detection of sufficient memory for the single memory allocation within the buffer of the transport layer for at least the specified length, wherein waking the send socket call triggers a kernel to perform the single memory allocation in the buffer and to write the data to the single memory allocation in a single pass.

Claims

1. A method for efficient handling of a send socket call received at a transport layer of a network protocol stack of a computer system, comprising:

responsive to receiving said send socket call for data of a specified length at said transport layer and detecting insufficient memory for a single memory allocation to a buffer in said transport layer for at least said specified length, blocking said send socket call at said transport layer; and

only waking said send socket call upon detection of sufficient memory for said single memory allocation of at least said specified length within said buffer in said transport layer, wherein waking said send socket call triggers a kernel to perform said single memory allocation of said at least said specified length in said buffer and to write said data to said single memory allocation in a single pass.

2. The method according to claim 1, further comprising:

receiving said send socket call at said transport layer with a flag set requiring only said single memory allocation in said buffer for said send socket call.

3. The method according to claim 1, further comprising:

responsive to blocking said send socket call, setting a minimum memory allocation size to said specified length, wherein said transport layer automatically only wakes said send socket call upon detection of sufficient memory for said minimum memory allocation size.

4. The method according to claim 1, further comprising:

responsive to blocking said send socket call, setting a blocked thread size to said specified length, wherein said transport layer automatically only wakes said send socket call upon detection of sufficient memory for said blocked thread size, wherein said blocked thread size is independent of a setting specifying a minimum memory allocation size within said buffer.

5. The method according to claim 1, further comprising:

responsive to detecting, at said transport level, an acknowledgment of received data, adjusting a counter indicating an amount of available memory for allocation to said buffer by an amount indicated in said acknowledgment.

6. The method according to claim 1, wherein said memory for allocation to said buffer is held in a memory pool designated for allocation among a plurality of buffers at said transport level.

7. The method according to claim 1, wherein said single memory allocation is an mbuf.

8. The method according to claim 1, further comprising:

detecting a maximum segment size receivable by a system receiving said data; and

setting a maximum amount of memory allocable at one time to said buffer to an amount larger than said maximum segment size.

9. A system for efficient handling of a send socket call, comprising:

a computer system enabled for communication over a network by a network protocol stack comprising at least a transport layer for receiving said send socket call;

said transport layer comprising means for blocking said send socket call, responsive to receiving said send socket call for data of a specified length and detecting insufficient memory for a single memory allocation to a buffer in said transport layer for at least said specified length; and

said transport layer comprising means for only waking said send socket call upon detection of sufficient memory for said single memory allocation of at least said specified length within said buffer in said transport layer, wherein waking said send socket call triggers a kernel to perform said single memory allocation of said at least said specified length in said buffer and to write said data to said single memory allocation in a single pass.

10. The system according to claim 9, said transport layer further comprising:

means for receiving said send socket call with a flag set requiring only said single memory allocation in said buffer for said send socket call.

11. The system according to claim 9, said transport layer further comprising:

means, responsive to blocking said send socket call, for setting a minimum memory allocation size to said specified length, wherein said transport layer automatically only wakes said send socket call upon detection of sufficient memory for said minimum memory allocation size.

12. The system according to claim 9, said transport layer further comprising:

means, responsive to blocking said send socket call, for setting a blocked thread size to said specified length, wherein said transport layer automatically only wakes said send socket call upon detection of sufficient memory for said blocked thread size, wherein said blocked thread size is independent of a setting specifying a minimum memory allocation size within said buffer.

13. The system according to claim 9, said transport layer further comprising:

means, responsive to detecting an acknowledgment of received data, for adjusting a counter indicating an amount of available memory for allocation to said buffer by an amount indicated in said acknowledgment.

14. The system according to claim 9, wherein said memory for allocation to said buffer is held in a memory pool designated for allocation among a plurality of buffers at said transport level.

15. The system according to claim 9, wherein said single memory allocation is an mbuf.

16. The system according to claim 9, said transport layer further comprising:

means for detecting a maximum segment size receivable by a system receiving said data; and

means for setting a maximum amount of memory allocable at one time to said buffer to an amount larger than said maximum segment size.

17. A program for efficient handling of a send socket call received at a transport layer of a network protocol stack, said program embodied in a computer-readable medium, said program comprising computer-executable instructions which cause a computer to perform the steps of:

controlling blocking of said send socket call, responsive to receiving said send socket call for data of a specified length and detecting insufficient memory for a single memory allocation to a buffer for at least said specified length; and

controlling waking of said send socket call only upon detection of sufficient memory for said single memory allocation of at least said specified length within said buffer, wherein waking said send socket call triggers a kernel to perform said single memory allocation of said at least said specified length in said buffer and to write said data to said single memory allocation in a single pass.

18. The program according to claim 17, further comprising:

enabling receipt of said send socket call at said transport layer with a flag set requiring only said single memory allocation in said buffer for said send socket call.

19. The program according to claim 17, further comprising:

setting a minimum memory allocation size to said specified length, responsive to controlling blocking of said send socket call, wherein said transport layer automatically only wakes said send socket call upon detection of sufficient memory for said minimum memory allocation size.

20. The program according to claim 17, further comprising:

setting a blocked thread size to said specified length, responsive to blocking said send socket call, wherein said transport layer automatically only wakes said send socket call upon detection of sufficient memory for said blocked thread size, wherein said blocked thread size is independent of a setting specifying a minimum memory allocation size within said buffer.