JP2008236378A - Data transfer method between host computer and network interface controller, program and network interface controller - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a data transfer system between an NIC (network interface controller) that allows flexible network correspondence by software processing, and a host computer by minimizing an additional function to hardware of the network interface controller. <P>SOLUTION: The host computer creates a header table comprising a common header composed of header information common to transmission data, a variable header composed of unique header information in each packet and a pointer showing a storage address of a payload of the packet, and the NIC creates a header of a packet on the basis of the header table, extracts the payload to creates a packet. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a data transfer method between a host computer and a network interface controller that is provided between a host computer and a network and transmits a packet obtained by dividing transmission data of the host computer to the network.

  In today's computer systems, high-speed data exchange with the outside is an important issue that leads to high speed of the entire system. In particular, in a cluster system in which small computer systems such as PCs are connected via a network and used as one large computer system as a whole, information transmission via the network is an important factor that determines the calculation speed of the entire system. . For this reason, the data communication performance of the computer system is improving year by year, and the improvement rate averages a very high value of about twice in about three years. This is faster than the speed of computer computing devices. As data communication performance improves in this way, the configuration of a connection device for connecting a high-speed computing device and a high-speed network becomes an important issue.

  Generally, when a computer system is connected to a network, a connection device called a network interface controller (hereinafter sometimes referred to as NIC) is interposed. As a result, the computer system (hereinafter sometimes referred to as a host computer or a host) can be adapted to various types of networks simply by changing the NIC, and the flexibility of the configuration can be ensured.

FIG. 7 is a diagram illustrating a configuration of a system that transmits a packet from a host computer to a network using a network interface controller.
The host computer 1 and the NIC 5 are connected via an interface called an I / O bus 4 for connecting to an external input / output device prepared by the host computer 1. Standards such as PCI, PCI-X, and PCI Express are widely used for the I / O bus 4. The host computer 1 sends data and instructions to the NIC 5 via the I / O bus 4 and exchanges data via the network 6.

  Data on the network 6 is transferred in the form of packets. A packet is generally composed of a header and a payload. In the header, various information for communication, for example, a transmission source and a transmission destination, a protocol type, a data length, and the like are described. The payload is the data itself to be transmitted, and the receiving party determines how to handle the payload based on the header information and performs processing.

  Therefore, when transferring data from the host computer 1 to the outside, the CPU 2 of the host computer 1 creates a header based on the control information 31 on the memory 3 and adds it to the data 32 to form a packet. It is necessary to send it out to the network 6 via.

By the way, the maximum size of the packet is determined depending on the type of the network 6.
For example, in Ethernet (registered trademark), the upper limit is about 1500 bytes, and packets longer than that cannot be transmitted and received. Therefore, if the host computer 1 tries to send large data 32 of 1500 bytes or more, the data 32 is changed to 150.
It must be divided into sizes smaller than 0 bytes, each with a header, and sent to the network as separate packet # 1, packet # 2, ..., packet #n.

  Since the maximum packet size is fixed by the network 6, the larger the original data 32, the larger the number of packets. Since a header must be attached for each packet, a large number of packets means that the number of headers increases.

FIG. 8 is a diagram for explaining a conventional method of transferring data via a network using the NIC 5.
First, control software running on the CPU 2 of the host 1 to which the NIC 5 is connected receives data 32 to be transmitted and control information 31 for transfer (not shown in FIG. 8). Next, the control software secures an area 33 for the packet, and generates a header there based on the control information 31. Further, a part of the data 32 is copied to construct a packet. By giving a transfer instruction to the controller 51 of the NIC 5, this packet is transferred to the buffer 52 of the NIC 5, and further the packet is transmitted from the NIC 5 to the network 6. This procedure is repeated until all the data 32 has been transferred.

When data is packetized and transferred to the network by the above method, the following problems occur.
(I / O bus problem)
As described above, the NIC 5 is connected to the computer system 1 via the I / O bus 4. The computer system 1 transmits / receives instructions and data to the NIC 5 via the I / O bus 4.

  As this I / O bus 4, a high-speed one such as PCI Express is currently used, and a data transfer speed higher than the speed of the network 6 is ensured. However, the I / O bus 4 has a problem that the initial overhead is large. The initial overhead is the time from the start of data transfer to the actual start of data flow. This initial overhead is not a problem when a large amount of data is transferred, but becomes an important problem when a small amount of data is transferred.

  When transferring data via the I / O bus 4, many small data transfers such as sending only the header to the NIC 5 or sending a transmission instruction to the NIC 5 occur. Therefore, there is a need for a transfer method for reducing the small number of data transfer times and reducing the influence of the large initial overhead of the I / O bus 4.

(Data copy problem)
The method of creating and transferring one packet at a time requires copying data from the original data to the packet. Since this needs to be performed over the entire data, the larger the data, the greater the number of copies.

  Currently, as the speed of the network 6 increases, the difference in transfer speed between the computing device of the computer system 1 and the network 6 is reduced. This means that the processing capability of the arithmetic device is lower than that of the network 6 when viewed relatively. In such a situation, the data copy processing by software becomes very heavy processing, and this becomes a factor for reducing the overall performance of the cluster system, for example. Therefore, there is a need for a data transfer method that does not involve copying data as much as possible.

(Header creation problem)
When transferring data to the network 6, it is necessary to create a header. This header differs depending on the type of network 6, and it is necessary to create a header corresponding to each network 6.

  If the data to be sent to the network 6 is large, the large chunk of data must be divided to fit within the maximum packet size, and a header must be attached to each. At this time, it is necessary to create as many headers as the number of packets, but these headers have a lot of common information. For example, the source, destination, and protocol type are common to all packets.

  Although there is a lot of common information in this way, each packet must be handled as a separate packet. This causes overhead of the control software on the host 1 and wasteful data passes through the I / O bus 4. The data is sent from the host 1 to the NIC 5, which causes a decrease in performance. Therefore, it is desirable to use a method that does not create and exchange as much useless information as possible.

In order to solve the above problems, several new methods have been proposed so far.
(Bulk transmission method)
In the transmission method described in FIG. 8, a transfer instruction is given to the controller 51 of the NIC 5 every time one packet is created. Since a transfer instruction to the NIC 5 via the I / O bus 4 involves a very large overhead, this method is wasteful.

Therefore, the control software of the host 1 secures as many areas 33 for packets as necessary, creates a plurality of packets continuously, and collects transfer instructions for these packets all at once. Is considered. If this method is used, the overhead of the transfer instruction via the I / O bus 4 can be reduced.
However, the remaining two problems, the data copy problem and the header creation problem, remain as they are.

(Gather table method)
The gather table is a table in which a plurality of pointers to data are collected. By using a gather table, it is possible to pass the data arranged separately without passing them one by one.

FIG. 9 is a diagram for explaining a method in which the gather table is applied to transfer processing between the host 1 and the NIC 5.
Control software running on the CPU 2 of the host 1 receives data 32 to be transmitted and control information 31 for transfer (not shown in FIG. 9). Next, the control software secures areas 34 for a plurality of headers, and generates a plurality of headers there based on the control information 31. Also, an area 35 for the gather table is secured, and a gather table is created in which the pointer to the header and the pointer to the data corresponding to the header are gathered, and the address notification of the area 35 is sent to the controller 51 of the NIC 5. The transfer instruction is included.

  The controller 51 secures an area 53 for reading and storing the gather table on the host 1, and reads the gather table from the host 1 to the area 53. Next, the header and data are extracted from the host 1 by the pointers on the gather table, and are collected as packets by the packet buffer 52 and transmitted to the network 6.

By using the gather table, the host 1 does not need to copy data and generate a packet. This solves the problem of data copying.
However, the header creation problem remains. Further, since the NIC 5 has to take out the header via the I / O bus 4, there arises a problem that the overhead of the I / O bus 4 increases.

(Off-road engine method)
An off-road engine method has been proposed as a method for solving all of the above problems. The offload engine is hardware on the NIC that performs packet processing.

FIG. 10 is a diagram for explaining the off-road engine system.
From the CPU 2 of the host 1, header creation information as information necessary for packet transmission is preliminarily passed to the offload engine 55 of the NIC 5 and registered in the area 54, and a transfer instruction is issued by notifying only the position of the data 32. .

  The NIC 5 creates a header based on the information registered in the area 54, reads data necessary for the packet via the I / O bus 4 (not shown), generates the packet in the area 52, and transmits it to the network 6.

Since the offload engine method passes only necessary information, the overhead of the host 1 is small. Therefore, it can be said that this is the most efficient transfer method.
However, the offload engine method has a problem that the processing in the NIC 5 becomes complicated. If the offload engine 55 mounted on the NIC 5 is configured by hardware, the NIC 5 can only perform specific network processing built in hardware, and thus lacks flexibility in network processing.

  On the other hand, when the offload engine 55 is composed of a microprocessor and software (firmware) mounted on the NIC 5, it is required for high speed because it is intended for header generation and other processes that are originally performed by the host 1. Requires expensive hardware.

As described above, since the processing in the NIC 5 becomes complicated, there arises a problem that the flexibility is insufficient or the hardware becomes expensive.
Patent Document 1 and Patent Document 2 below propose network interface controllers for TCP / IP or UDP / IP using an offload engine system. These methods are specific to a specific protocol, TCP / IP or UDP / IP, and cannot be applied to other protocols.

In addition, as network technology develops, the same TCP / IP and UDP / IP may be extended. In the method of configuring the header with software on the host etc., it can be realized just by introducing new software, but when the offload engine is configured with hardware, it can be handled if the hardware itself is not replaced. Can not.
JP 2006-081033 A JP 2006-526969 A

The object of the present invention is to solve the above-mentioned problems of I / O bus, data copy, and header creation, and to minimize the additional functions to the network interface controller hardware, thereby making the network interface controller hardware complicated and expensive. It is to realize a data transfer method between a network interface controller and a host computer, which enables flexible network support by software processing without making anything.

  A structure called a header table is newly introduced for information transfer regarding packets between the host computer and the network interface controller. In the header table, compressed header information of the packet and a pointer to the payload data of the packet are described.

  The header information is compressed by decomposing information described in the header into a common header and a variable header. The common header is information common to all packets obtained by dividing one transmission data, and corresponds to, for example, a transmission source, a transmission destination, and a protocol type. The variable header is different information for each packet, and corresponds to, for example, a sequence number and checksum information.

  The network interface controller creates the header of each packet based on the common header of the header table and the contents of the variable header corresponding to each packet, acquires data from the host computer with the pointer, and constructs the packet internally.

  The header can be generated inside the network interface controller by the transfer method using the header table of the present invention. When the header information is passed from the host computer to the network interface controller, the common header is only once for the transmission data sent at a time, and the variable header is only the number of packets, so duplicate information is transferred many times. Never do.

Also, since the packet is created inside the network interface controller, there is no problem of payload copy.
The header table of the present invention is created by a control program on the host computer. Therefore, the packet header configuration can be freely changed by software on the host computer, and various protocols can be flexibly supported.

FIG. 1 is a diagram for explaining the principle of packet creation according to the present invention.
As shown in FIG. 1A, the control information used for packet creation in the present invention includes a common part, a variable part 1 for packet # 1, a data pointer for packet # 1,..., For packet #n. A variable part n and a data pointer for packet #n are configured. The control information of the common part is information used for the common header of the header table, and the control information of each variable part is information used for each variable header of the header table.

  As described above, the control information of the common unit is, for example, a transmission source, a transmission destination, and a protocol type, and the control information of each variable unit is, for example, a sequence number, checksum information, or the like. In the protocol in which the checksum information is set in the trailer, each trailer can be transferred by being included in the data n shown in FIG. 1B, which is the last payload data.

The transmission data is divided into data 1, data 2,..., Data n as shown in FIG. 1 (b), and the head address of each is indicated by the pointer of the control information shown in FIG.
Based on the control information shown in FIG. 1A and the data shown in FIG. 1B, packet # 1, packet # 2,..., Packet #n shown in FIG. The headers of packet # 1, packet # 2,..., Packet #n are created from the control information of the common part and the control information of the variable part, as shown in FIG.

FIG. 2 is a diagram illustrating an outline of an information transfer method for creating a packet between a host and a NIC according to an embodiment of the present invention.
The CPU 2 on the host side generates a header table 36 for each piece of transmission data 32. The header table 36 includes a common header common to transmission data, a variable header for each data transmitted by each packet obtained by dividing a single transmission data, and a pointer to data transmitted by each packet.

  When the CPU 2 on the host side issues a transfer instruction to the header interpretation / configuration engine 56 on the NIC side, the header interpretation / configuration engine 56 reads the header table 36 and stores it in the header table buffer 57 to synthesize the common header and variable header. Packet header. Further, the header interpretation / configuration engine 56 reads the data from the host side by using a pointer indicating the position of the data to be stored in the header table stored in the header table buffer 57 and combines the packet with the packet buffer 52 together with the header previously synthesized. Create and send to the network side.

FIG. 3 is a diagram showing a configuration example of each variable header of the header table 36 according to the embodiment of the present invention.
As shown in FIG. 3, the head of the variable header is a length portion that indicates the length of the entire variable header. After that, it corresponds to each variable data, which is a type T indicating whether the length of the variable data is byte, word or double word, etc., and O indicating the offset from the head of the common header for writing the variable data. , And variable data D that is the data itself to be rewritten. In the example shown in FIG. 3, there are five variable data D0 to D4.

  FIG. 4 is a diagram illustrating a configuration example of the NIC 5a according to the embodiment of the present invention. FIG. 4 shows only a block configuration of a part related to packet transmission of the NIC 5a, and a part related to reception is omitted.

  As shown in FIG. 4, the packet transmission unit of the NIC 5a includes a host interface 50, a packet buffer 52, a controller 561, a header synthesis unit 562, a header table buffer 57, and a common header buffer 58. The controller 561 and the header synthesis unit 562 correspond to the header interpretation / configuration engine 56 shown in FIG.

  The NIC 5a is connected to an I / O bus (not shown) and a network, and exchanges data and the like with a host (not shown) via the I / O bus. The host interface 50 is a block that communicates with the host, and performs operations such as receiving a transfer instruction from the host and issuing a memory read request to the host.

  The central controller 561 is a block that executes a packet transmission procedure, and is activated by the host interface 561 according to a transfer instruction received from the host. When activated, the controller 561 reads the header table from the host, instructs the header synthesis unit 562 to perform header synthesis, reads data from the host, and creates and creates a packet combining the header and data on the packet buffer 52. The transmission of the received packets to the network is sequentially performed.

  The header synthesis unit 562 is a block that synthesizes the common header stored in the common header buffer 58 and the variable header read from the header buffer table 57 to generate a header for a new packet.

  The header synthesis unit 562 repeats the operation of writing “DATA” in the size indicated by “T” in the offset destination indicated by “O” of the variable header shown in FIG. Create a header for.

  That is, according to the offset value, the header synthesizing unit 562 finds a portion to be rewritten in the common header and rewrites it with the data in the variable header, thereby creating a header suitable for each packet.

  The hardware for realizing the NIC 5a shown in FIG. 4 includes an area for storing a common header in the network interface controller hardware that is normally used, a variable header, and a packet header combined with the common header. The circuit to create is added. Therefore, it is possible to solve the problem of lack of flexibility, which has been a problem with the offload engine system, or requiring expensive hardware as a CPU.

  FIG. 5 is a diagram illustrating an operation sequence of the control program (OS) on the host and the hardware on the NIC side according to the information transfer method for packet transmission between the host and the NIC according to an embodiment of the present invention.

  The control software (OS) on the host is activated by a data transmission request from the user, secures an area on the memory in step S10, and allocates it to the header table 36 for transmission data.

In step S11, a common header is created according to the protocol of the network that transmits data to the head of the header table 36 and the common data of each packet.
Next, in step S12, the transmission data is divided according to the maximum packet size of the network, a variable header is created for each divided transmission data, and a pointer is set to the transmission data divided in step S13, and these are sequentially set. Are stored in the header table 36.

  As a result of the determination in step S14, steps S12 and S13 are repeated by the number of transmission data divisions, that is, the number of packets. When the header table 36 is completed, a transfer instruction is issued to the NIC side in step S15.

On the NIC side, when receiving a transfer instruction from the host side, the header table 36 is read from the host side and stored in the header table buffer 57 in step S20.
As a specific transfer method of the header table 36, a method of including the address of the header table in the transfer instruction from the host side, a method of setting the address of the header table 36 on the NIC side in advance, or the like is possible. Further, instead of these methods, the header table 36 can be transferred as write data to the NIC side together with a transfer instruction from the host side.

  In any case, the data of the header table 36 is transferred to the NIC side, and the NIC side acquires information of the header table. In the present specification and claims, the term “acquisition” is used for both reading the header table from the host side and receiving the header table transferred as write data by the host side.

Further, when the transfer of the header table is viewed from the host side, it may be described that the header table is passed from the host to the NIC.
In step S 21, the common header is extracted from the header table stored in the header table 57 and stored in the common header buffer 58.

  Subsequently, in step S22, the variable header corresponding to each packet is sequentially extracted from the header table buffer 57, and the header is synthesized using the common header extracted from the common header buffer 58 in step S23 and the variable header extracted in step S22. Write to the header area of the buffer 52.

  Steps S22 and S23 are executed by the header synthesis unit 562 shown in FIG. 4 as described above. The specific processing of the header synthesis is also as described above. First, the common header is written into the header area of the packet buffer 52, and then a part of the common header is rewritten with the variable data set in the variable header. .

  That is, “DATA” is written by the number of variable data from the start address of the header area to the offset destination indicated by “O” of the variable header with the size indicated by “T”. When executing the above processing, the header synthesis unit 562 determines where the data to be processed next is in the variable header and whether all the data has been processed, based on the length portion of the variable header and the value of the type T. Obviously we can do it.

  Progressing to step S24 following step S23, the data pointer to the data corresponding to each packet is extracted from the header table buffer 57, and in step S25, the host interface 50 is requested to read data from the host side by the data pointer. The read data is written in the data area of the packet buffer to create one packet.

Next, the packet created in step S26 is transmitted to the network, and it is determined in step S27 whether all the data in the header table has been processed.
If unprocessed data remains in the header table, the process returns to step S22 and the subsequent processes are repeated. If all the processes are completed, a process end notification is returned to the host side.

  When the host receives the process end notification from the NIC side, the host releases the header table 36 in step S16, and in step S17, notifies the user who has made the transmission request of the completion of transmission and ends the series of processes.

  As described above, the common header is created by software on the host in a format that conforms to the protocol of the network and information such as a common destination for data requested by the user. Therefore, it is a template for creating a packet header. The variable header is also created by software on the host, and is composed of information peculiar to each packet and information indicating a position in the header in which the packet is written, and indicates a changed portion of the template.

  Therefore, as long as a packet is composed of a header and a payload, the packet information transfer method using the header table of the present invention can be applied to all packet transfer protocols. Also, as previously mentioned, the trailer can be included in the payload of the last packet.

  In the description of the NIC 5a with reference to FIGS. 4 and 5, the common header buffer 58 is provided, the common header is copied from the header table buffer 57, and the header synthesis unit 562 accesses the header. It is also possible to configure so that 562 directly accesses the common header stored in the header table buffer 57.

Further, the above-described NIC 5a is configured by hardware oriented, but this is until the explanation that the transfer method using the header table of the present invention can be suitably realized by the NIC by the hardware configuration. This does not deny that the present invention can be implemented using software.

FIG. 6 is a diagram illustrating a configuration example of the network interface controller in the embodiment using a microprocessor (CPU) and a software configuration on the CPU.
As illustrated in FIG. 6, the NIC 5 b includes a host interface 50, a CPU 560, and a memory 570.

  In the memory 570, a header table buffer 571, a common header buffer 572, and a packet buffer 573 are secured. As described above, the common header buffer 572 can be omitted. In some cases, the common header buffer may be configured by a register.

Software processing in the CPU 560 is the same as that represented by the flow of steps S20 to S27 shown in FIG.
According to the transfer method using the header table according to the present invention, since the data necessary for packet creation is collected in the header table, the processing by the CPU 560 is not so heavy, and an inexpensive one can be used. Depending on the application field, it can be suitably employed.

  In the above, the present invention has been described without particularly mentioning the number of network lines accommodated in the NIC. The present invention is not limited to a NIC that accommodates only one network line. The line that connects the network and the NIC shown in each figure may be described by a single thick line, or may be a plurality of lines. It is written together.

  In the case of a NIC that accommodates a plurality of lines, for example, there is information for identifying a destination in the common header, and a NIC that accommodates a plurality of lines naturally includes a plurality of packets based on information for identifying the destination. Since there is means for distributing to one of the lines, it is only necessary to determine to which line the packet is transmitted.

  In addition, when link aggregation is used in which a plurality of physical lines are combined and used as one logical line, information on which physical line is to be transmitted is set in the variable header portion, and the line for transmitting the packet is set. Can be specified. Of course, a NIC that employs link aggregation can transmit packets to a designated physical line.

  The transfer method between the host computer and the network interface controller of the present invention is not limited to the so-called inter-computer communication host and NIC, but in all fields using packet communication, for example, in the field of mobile communication using packets. Obviously, this is also applicable.

  As for the connection form of the network connected to the network interface controller, the network line does not have to be directly connected to the network interface controller, and the modulation unit that modulates the packet data output from the network interface controller with various modulation schemes and various types This includes the case where it is connected to a network line via an encoding unit or the like that performs encoding.

As is apparent from the detailed description of the present invention described above, according to the present invention, the problem of I / O bus and the problem of data copy can be maintained without using expensive hardware while maintaining the flexibility to change the network. The header generation problem can be solved. I /
The exchange between the host and the NIC via the O bus and the overhead of the control program on the host can be reduced, and the data can be efficiently sent to the network.

(Appendix 1)
In a data transfer method between a network interface controller and a host computer, which is provided between a host computer and a network and transmits a packet created by dividing transmission data of the host computer to the network.
The host computer
A header in which, for each transmission data, a common header composed of header information common to the transmission data, a variable header composed of unique header information for each packet, and a pointer indicating a storage address of data serving as the payload of the packet are set Create a table,
Transfer instructions to the network interface controller,
Passing the header table to the network interface controller;
The network interface controller is
Read the data serving as the payload of the packet from the host computer with the pointer set in the passed header table.
A data transfer method characterized by the above.
(Appendix 2)
The data transfer method according to appendix 1, wherein the variable header includes data to be written to the common header and position information indicating a position to write the data to the common header.
(Appendix 3)
The data transfer method according to appendix 2, wherein the network interface controller accommodates a plurality of lines of the network, and the common header includes information for identifying the lines.
(Appendix 4)
The network interface controller accommodates a network line that operates a plurality of physical lines by link aggregation, and the variable header includes information identifying the physical line to which a corresponding packet is transmitted. The data transfer method according to Supplementary Note 2, wherein
(Appendix 5)
The data transfer method according to any one of appendix 1 to appendix 4, wherein the host computer passes the header table by reading from the network interface controller.
(Appendix 6)
The data transfer method according to any one of appendix 1 to appendix 4, wherein the host computer passes the header table by writing to the network interface controller.
(Appendix 7)
A host computer that is provided between the host computer and the network and transfers data to a network interface controller that transmits a packet created by dividing the transmission data of the host computer to the network;
A header in which, for each transmission data, a common header composed of header information common to the transmission data, a variable header composed of unique header information for each packet, and a pointer indicating a storage address of data serving as the payload of the packet are set A means to create a table;
Means for instructing transfer to the network interface controller;
Means for passing the header table to the network interface controller;
A program characterized by making it function.
(Appendix 8)
The program according to appendix 7, wherein the variable header includes data to be written to the common header and position information indicating a position to write the data to the common header.
(Appendix 9)
In a network interface controller that is provided between a host computer and a network and transmits a packet created by dividing transmission data of the host computer to the network,
A control unit, a header synthesis unit, and a buffer unit;
The control unit indicates a common header composed of header information common to the transmission data obtained from the host computer, a variable header composed of unique header information for each packet, and a storage address of data serving as a payload of the packet A header table in which a pointer is set is stored in the buffer unit, the header synthesis unit is instructed to synthesize a header, and data serving as a payload of a packet is read out by the pointer set in the header table and the buffer Stored in the payload data storage area of
The header synthesis unit reads the common header and the variable header from the buffer unit, synthesizes the common header and the variable header to create a packet header, and stores the packet header in a packet header storage area of the buffer.
A network interface controller characterized by that.
(Appendix 10)
The network interface controller according to appendix 9, wherein the variable header includes data to be written to the common header and position information indicating a position to write the data to the common header.
(Appendix 11)
The variable header further includes a length portion indicating the length of the entire variable header, and a type portion indicating the length of the data for each data to be written to the common header, and the control portion includes the length portion and the type portion. 11. The network interface controller according to appendix 10, wherein the data to be written to the common header is extracted from the variable header based on the length information and all the write data has been extracted.
(Appendix 12)
The network includes a plurality of lines in the network, the common header includes information for identifying the line, and transmits a packet created on the line based on the information for identifying the line. Or the network interface controller according to any one of appendix 11.
(Appendix 13)
Based on the information for identifying the physical line, which accommodates the line of the network that operates a plurality of physical lines by link aggregation, and the variable header includes the physical line to which the corresponding packet is transmitted. The network interface controller according to any one of appendix 9 to appendix 11, wherein the packet created on the physical line is transmitted.
(Appendix 14)
To the network interface controller that is provided between the host computer and the network and transmits the packet created by dividing the transmission data of the host computer to the network,
A header table in which a common header composed of header information common to the transmission data from the host, a variable header composed of unique header information for each packet, and a pointer indicating a storage address of data serving as a payload of the packet is acquired. Function to
A function of reading data serving as a payload of the packet by a pointer indicating a storage address of data serving as a payload of the packet in the header table;
A function of creating a header of each packet by combining the common header and each variable header;
A program characterized by realizing.
(Appendix 15)
15. The program according to appendix 14, wherein the variable header includes data to be written to the common header and position information indicating a position to write the data to the common header.

It is a figure explaining the principle of packet preparation by this invention. It is a figure explaining the outline | summary of the transfer system between the host and NIC by one Embodiment of this invention. It is a figure which shows the structure of the variable header by one Embodiment of this invention. It is a figure which shows the structural example of NIC by one Embodiment of this invention. It is a figure explaining the operation | movement sequence which concerns on the transfer system by one Embodiment of this invention. It is a figure which shows the structural example of NIC in the Example by a software structure. It is a figure which shows the structure which transmits a packet from a host using NIC. It is a figure explaining the conventional system which transfers data using NIC. It is a figure explaining a gather table system. It is a figure explaining an off-road engine system.

Explanation of symbols

1 Host computer 2 CPU
3 Memory 4 I / O bus 5, 5a, 5b Network interface controller (NIC)
6 Network 36 Header Table 50 Host Interface 52 Packet Buffer 56 Header Interpretation / Configuration Engine 561 Controller 562 Header Synthesis Unit 57 Header Table Buffer 58 Common Header Buffer

Claims (5)

In a data transfer method between a network interface controller and a host computer, which is provided between a host computer and a network and transmits a packet created by dividing transmission data of the host computer to the network.
The host computer
A header in which, for each transmission data, a common header composed of header information common to the transmission data, a variable header composed of unique header information for each packet, and a pointer indicating a storage address of data serving as the payload of the packet are set Create a table,
Transfer instructions to the network interface controller,
Passing the header table to the network interface controller;
The network interface controller is
Read the data serving as the payload of the packet from the host computer with the pointer set in the passed header table.
A data transfer method characterized by the above.   The data transfer method according to claim 1, wherein the variable header includes data to be written to the common header and position information indicating a position to write the data to the common header. A host computer that is provided between the host computer and the network and transfers data to a network interface controller that transmits a packet created by dividing the transmission data of the host computer to the network;
A header in which, for each transmission data, a common header composed of header information common to the transmission data, a variable header composed of unique header information for each packet, and a pointer indicating a storage address of data serving as the payload of the packet are set A means to create a table;
Means for instructing transfer to the network interface controller;
Means for passing the header table to the network interface controller;
A program characterized by making it function. In a network interface controller that is provided between a host computer and a network and transmits a packet created by dividing transmission data of the host computer to the network,
A control unit, a header synthesis unit, and a buffer unit;
The control unit indicates a common header composed of header information common to the transmission data obtained from the host computer, a variable header composed of unique header information for each packet, and a storage address of data serving as a payload of the packet A header table in which a pointer is set is stored in the buffer unit, the header synthesis unit is instructed to synthesize a header, and data serving as a payload of a packet is read out by the pointer set in the header table and the buffer Stored in the payload data storage area of
The header synthesis unit reads the common header and the variable header from the buffer unit, synthesizes the common header and the variable header to create a packet header, and stores the packet header in a packet header storage area of the buffer.
A network interface controller characterized by that. To the network interface controller that is provided between the host computer and the network and transmits the packet created by dividing the transmission data of the host computer to the network,
A header table in which a common header composed of header information common to the transmission data from the host, a variable header composed of unique header information for each packet, and a pointer indicating a storage address of data serving as a payload of the packet is acquired. Function to
A function of reading data serving as a payload of the packet by a pointer indicating a storage address of data serving as a payload of the packet in the header table;
A function of creating a header of each packet by combining the common header and each variable header;
A program characterized by realizing.