COALESCING MESSAGES USING A NETWORK INTERFACE CONTROLLER

• US 20170064051A1
• Filed: 08/28/2015
• Published: 03/02/2017
• Est. Priority Date: 08/28/2015
• Status: Active Grant

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: Steinmacher-Burow, Burkhard
• Granted Patent: US 9,749,266 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: H04L 45/74 Address processing for routing
• CPC Class Codes: H04L 47/10 Flow control; Congestion control
• CPC Class Codes: H04L 49/90 Buffering arrangements
• CPC Class Codes: H04L 69/22 Parsing or analysis of headers
• CPC Class Codes: H04L 69/324 in the data link layer [OSI layer 2], e.g. HDLC

Abstract

An injection descriptor corresponding to a destination node may be stored in memory. A network interface controller (NIC) may determine that one or more messages added to the injection descriptor are to be transmitted to the destination node. The NIC may then lock the injection descriptor so that no additional message can be added to the injection descriptor, and the NIC may load the one or more messages. The NIC may then generate a network packet that includes the one or more messages, and the NIC may transmit the network packet to the destination node.

Claims

1. A computer implemented method for coalescing messages, the method comprising:

storing, in a memory, an injection descriptor, the injection descriptor corresponding to a destination node;

determining, by a network interface controller (NIC), that one or more messages added to the injection descriptor are to be transmitted to the destination node, the NIC having direct memory access (DMA) to the memory;

locking, by the NIC, the injection descriptor to prevent an additional message from being added to the injection descriptor;

loading, by the NIC, the one or more messages;

generating, by the NIC, a network packet, the network packet including the one or more messages; and

transmitting, by the NIC, the network packet to the destination node.

2. The method of claim 1, wherein at least two messages have been added to the injection descriptor, and wherein the generating, by the NIC, the network packet comprises coalescing the at least two messages.

3. The method of claim 1, the method further comprising:

generating, by an application, a message to be sent to the destination node; and

adding, by the application, the message to the injection descriptor.

4. The method of claim 3, the method further comprising:

determining, by the application, that the message is the only message added to the injection descriptor; and

adding, by the application, a pointer identifying the injection descriptor to an injection queue served by the NIC.

5. The method of claim 1, the method further comprising:

clearing, after loading the one or more messages and by the NIC, the injection descriptor; and

unlocking, after clearing the injection descriptor and by the NIC, the injection descriptor.

6. The method of claim 1, wherein the locking the injection descriptor comprises setting a flag in the memory, the flag indicating that the NIC is accessing the injection descriptor.

7. The method of claim 1, wherein the locking the injection descriptor comprises using a store-like atomic memory operation (AMO).

8. The method of claim 3, wherein the adding, by the application, the message to the injection descriptor comprises using a compare-and-swap (CAS) instruction.

9. The method of claim 3, wherein the adding, by the application, the message to the injection descriptor comprises using a load-link/store-conditional (LL/SC) instruction set.

10. A system for coalescing messages, the system comprising:

a processor;

a network interface controller (NIC);

a memory containing an injection descriptor and one or more modules, wherein the one or more modules, when executed, cause the processor to;

generate a message to be sent to a destination node;

add the message a set of memory addresses associated with the injection descriptor;

determine whether the message is the only message added to the set of memory addresses associated with the injection descriptor; and

add, in response to determining that the message is the only message added to the set of memory addresses, a pointer identifying the injection descriptor to an injection queue served by the NIC.

11. The system of claim 10, wherein the adding the pointer identifying the injection descriptor to the injection queue comprises using a compare-and-swap instruction.

12. The system of claim 10, wherein the adding the pointer identifying the injection descriptor to the injection queue comprises using a load-link/store-conditional instruction set.

13. The system of claim 10, wherein the NIC is configured to:

determine that one or more messages added to the set of memory addresses associated with the injection descriptor are to be transmitted to the destination node;

lock the injection descriptor to prevent an additional message from being added to the set of memory addresses associated with the injection descriptor;

load the one or more messages;

generate a network packet, the network packet including the one or more messages; and

transmit the network packet to the destination node.

14. The system of claim 13, wherein at least two messages have been added to the set of memory addresses associated with the injection descriptor, and wherein the NIC is further configured to coalesce the at least two messages.

15. The system of claim 13, wherein the NIC is further configured to:

clear, after loading the one or more message, the set of memory associated with the injection descriptor; and

unlock the injection descriptor.

16. The system of claim 13, wherein the locking the injection descriptor comprises setting a flag in the memory, the flag indicating that the NIC is accessing the injection descriptor.

17. The system of claim 13, wherein the locking the injection descriptor comprises using a store-like atomic memory operation.

18. A computer program product for coalescing messages, the computer program product comprising a computer readable storage medium having program instructions embodied therewith, wherein the computer readable storage medium is not a transitory signal per se, the program instruction executable by a processor to cause the processor to perform a method comprising:

generating a message to be sent to a destination node;

adding the message a set of memory addresses associated with an injection descriptor;

determining whether the message is the only message added to the set of memory addresses associated with the injection descriptor; and

adding, in response to determining that the message is the only message added to the set of memory addresses, a pointer identifying the injection descriptor to an injection queue served by a network interface controller (NIC).

19. The computer program product of claim 18, wherein the computer program product further includes program instructions executable by the NIC to cause the NIC to perform a method comprising:

determining that one or more messages added to the injection descriptor are to be transmitted to the destination node;

locking the injection descriptor to prevent an additional message from being added to the injection descriptor;

loading the one or more messages;

generating a network packet, the network packet including the one or more messages; and

transmitting the network packet to the destination node.

20. The computer program product of claim 19, the method performed by the NIC further comprising:

clearing, after loading the one or more messages, the injection descriptor; and

unlocking, after clearing the injection descriptor, the injection descriptor.