JP2000163354A - Data processing system and disk controller - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce the overhead due to a communication of channel command words(CCW) between a CPU and a DKC by allowing an input/output channel part to generate a CCW list by combining CCWs, adding a command frame including a CCW combination command to the CCW list, and transferring them to the disk controller. SOLUTION: A channel program is fetched from a main storage part MS to analyze command codes, and the contents of a channel program are put in channel program management information 331. Then commands, flag information, and a transfer count in the channel program are stored in a data buffer 334 to generate the channel command word(CCW) list. Then data and parameters as many as the transfer count are stored in the data buffer and the flag information in the channel program is decided; when a command chain flag is OFF, a command frame including a CCW combination command is generated, added to the CCW list, and issued to the disk controller(DKC).

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a data processing system provided with a central processing unit (hereinafter, referred to as a CPU) of a mainframe system and a disk control unit (hereinafter, referred to as a DKC). Hereafter, CC
W) is connected / separated to reduce a data transfer overhead between the CPU and the DKC.

[0002]

2. Description of the Related Art CPU and DK in a mainframe system
When performing data transfer with C, generally, DX
(Define Extext) / LOC (LOCate record), CP
For data transfer from U to DKC, the WRITE command is chained, and for data transfer from the DKC to the CPU, the READ command is chained. For example, when writing one record, DX / LOC / WRCKD (Write Count, Key
and Data) CCW chain (known example: IBM 399
0/9390 Storage Control Reference). Also, CPU-
Although there is an ESCON protocol as an interface between DKCs, when processing is performed in a configuration connected by this CCW chain ESCON, the following sequence is performed during normal operation (known example: Enterprise Systems Architecture / 3
90 ESCON I / O Interface). FIG. 2 shows an operation sequence. (1) CPU issues DX command frame (20
1) (2) Issuing a command response frame from the DKC (202) (3) Issuing a command response receiving frame from the CPU (203) (4) Issuing a DX command data frame from the CPU (204) (5) Status from the DKC Issue of frame (205) (6) Issue of LOC command frame from CPU (2)
06) (7) Issuing of command response from DKC (207) (8) Issuing of LOC command data frame from CPU (208) (9) Issuing of status frame from DKC (209) (10) Command frame of WRKD from CPU Issuing (210) (11) Issuing a command response frame from the DKC (211) (12) Issuing a WRCKD data frame from the CPU (212) (13) Issuing a WRCKD data frame from the CPU according to the data amount, or DKC issues data request frame (14) DKC issues status frame (21
3) (15) Issuance of status reception frame from CPU (2
14) (16) Issuance of Device Level ACK Frame from DKC (215) As described above, general DX / LOC on ESCON
When executing / WR or RD, it is necessary to execute the above-described sequences (1) to (11) between the CPU and the DKC until the actual data transfer processing is executed.

[0003]

In the above sequence, the path between the CPU and the DKC is occupied during the communication in the above sequences (1) to (11). There is a problem that performance is affected. Further, when the physical transfer speed between the CPU and the DKC is improved by the FIBER channel or the like in the future, there is a problem that the overhead due to the communication of the DX / LOC command or the like further affects the data transfer performance.

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned problem. The CPU side combines CCW chains, collectively transfers a plurality of CCWs to the DKC, and separates and processes the CCW chains on the DKC side. As a result, the CPU-DKC
An object of the present invention is to reduce overhead caused by communication between a plurality of CCWs.

[0005]

In order to achieve the above object, the present invention provides an arithmetic unit for executing a program / processing data, a main memory for storing a program / data, a main memory, and an external memory. In the data processing system having an input / output channel unit for controlling data transfer with a disk controller, the input / output channel unit creates a CCW list by combining a plurality of channel command words (hereinafter, referred to as CCW). And the CCW list
A means for adding a command frame including a W-coupled command and transferring the command frame to the disk controller is provided.

[0006] The CCW in the CCW list maintains the original CCW format.

[0007] Further, it has a control processor for managing data in the disk control device, a cache memory for storing data, and a channel control unit for controlling data transfer between the cache memory and an external data processing system. In the disk control device, when a CCW list in which a plurality of CCWs are combined and a command frame including a CCW combination command is transferred from the data processing system is transferred, each of the CCWs in the CCW list is It has means for separating and processing each separated CCW.

A data processing system comprising a central processing unit and a disk control unit connected to the central processing unit, the central processing unit comprising: an arithmetic unit for executing a program / processing data; A main storage device for storing programs / data; and an input / output channel unit for controlling data transfer between the main storage device and the disk controller. The input / output channel unit connects a plurality of CCWs. To create a CCW list, and add CCW to the CCW list.
Means for adding a command frame including a combined command and transferring the command frame to the disk controller, the disk controller comprising: a control processor for managing data; a cache memory for storing data; A channel control unit for controlling data transfer to and from a processing device, wherein the channel control unit, when a CCW list to which a command frame including the CCW combination command is added from the central processing unit is transferred, Each CCW in the CCW list is separated, and means for processing the separated CCWs is provided.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A data processing system in a mainframe according to an embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a diagram showing a configuration of a data processing system in a mainframe according to an embodiment of the present invention. The configuration of the present embodiment mainly includes a CPU (101) as a central processing unit, a DKC (102) as a disk control device, and a DKU as a disk drive device.
(103), a cable (104) connecting the CPU and the DKC, and a cable (105) connecting the DKC and the DKU. The interface between the CPU and the DKC is E, which is a mainframe standard protocol.
It may be SCON or may be based on the FIBER channel protocol. The configuration in the CPU includes an arithmetic processing unit (IP) (111) that executes an operating system, a user program, and the like, and a main storage unit (MS) (112) that stores the program, data processed by the program, and the like. And an input / output control unit (CH) (11) for controlling data transfer with an external input / output device and controlling an interface with the input / output device.
3) and a system controller (SC) (114) for controlling these data transfers. Also, DK
The configuration in C includes a channel control unit (121) for controlling the interface of the CPU with the channel, and a CACHE memory unit (122) for processing data at high speed.
And a control processor unit (123) that controls data management and the like in the DKC, and a data transfer control unit (124) that controls these data transfers. Further, a disk device (131) for storing data exists in the DKU. The connection of the CCW chain on the CPU side is processed by the CH. The CCW chain separation in the DKC is processed by the channel control unit.

FIG. 3 is a diagram showing a configuration for connecting CCW chains in the CPU. DX / LOC / WRCKD will be described as an example of the CCW chain.
In the MS, a channel program (311) as information for executing CCW, a DX parameter (312) as control data of a DX command, a LOC parameter (313) as control data of a LOC command, and WRCK
The actual data (314) to be written by the D command is stored. The structure in the channel program includes a command code (321) indicating a command to be executed, flag information (322) indicating command chain information indicating whether or not a next command exists, and a transfer count () indicating an amount of data transferred by the command. 323) and an address (3) indicating the position of the data / parameter stored in the MS.
24) exists. On the other hand, on the CH side, channel program management information (3
31), a channel program counter (332) for managing the execution state of the channel program, a control unit (333) for controlling the coupling of CCWs, and a data buffer (334) for storing a CCW list which is a coupling result of the CCW chains.
Consists of The structure of the channel program management information includes the same command code, flag information, transfer count, and address as those of the channel program in the MS. The structure of the CCW list in the data buffer includes a command code (341), flag information (3
42), a transfer counter (343), and transfer data (344). Using these components, CC
The processing flow for combining the W chains will now be described.

FIG. 4 is a diagram showing a processing flow for connecting CCW chains in the CPU.

First, a channel program is fetched from the MS according to the channel program counter (step 40).
1). By taking in, the value of the channel program counter is updated. Next, the command code in the fetched channel program is analyzed (step 402), and WRITE
If the command is a control command, the contents of the channel program are stored in the channel program management information (331) (step 403). Next, the command, flag information, and transfer count in the channel program are stored in the data buffer (334), and a CCW list is created (step 404). Next, data / parameters corresponding to the transfer count from the address in the channel program are stored in the data buffer (step 405). Data / parameters also become part of the CCW list. The data stored in the data buffer in FIG. 3 is an example of the CCW list. Next, the flag information in the channel program is determined (step 406). If the command chain flag is on, the process returns to the channel program fetching process from the MS. If the command chain flag is off, the process moves to issuing the combined CCW chain to the DKC. When issuing the combined CCW chain to the DKC, the CC
A command frame including a W-combined command is created, and this command frame is added to the created CCW list, and D
Issue to KC. That is, the CCW list is transferred to the DKC following the command frame.

On the other hand, command code analysis (step 4)
02) are READ and sense commands, the WRITE CCW and READ CCW
To prevent CCW from being coupled. At this time, first, the channel program management information is analyzed (step 407). If the CCW has been combined, that is, if the contents of the channel program are stored in the channel program management information (331), the channel that should not be combined is The channel program counter is set to 1
CCW decrement (step 408), CCW already joined
The process moves to issuing a chain to the DKC. If the result of analyzing the channel program management information indicates that the CCW has not been linked, that is, the channel program management information (3
If the content of the channel program is not stored in 31), the process proceeds to the CCW issuing process to the DKC as before. Through the above processing, the CCW chains can be connected.

FIG. 5 is a diagram showing a configuration for separating a CCW chain in a DKC. DX / LOC / WRCKD will be described as an example of the CCW chain.
The channel control unit (510) includes a control unit (511) for controlling CCW separation and a buffer (512) for storing the CCW list transferred from the CPU.
The structure of the CCW list in the buffer includes a command code (521), flag information (522), a transfer counter (523), and transfer data (524) as in the buffer on the CPU side. DX / LOC / WRCK
The data flow in the CCW chain of D is D
Control parameters such as X and LOC are referred to from the control processor via the data transfer control unit. Also, WRC
Actual data such as KD is stored in CACHE via the data transfer control unit under the control of the control processor. A processing flow for separating a CCW chain using these components will be described below.

FIG. 6 is a diagram showing a processing flow for separating a CCW chain in the DKC. First, the control unit (511) executes command frame reception processing (step 601). Next, a command code is extracted from the received command frame and analyzed (step 6).
02). If the content of the command code is a conventional command other than the CCW combination command, the process proceeds to the conventional processing.
If the content of the command code is a CCW connection command, the command response frame issuance processing (702 in FIG. 7) and the command response reception frame reception processing (FIG. 7) are performed as channel control for the CH (113).
703) is executed (step 603). Next, CC
The batch reception processing of the data frame containing the W list is executed, and the data is stored in the buffer (512) (step 604).

Next, the command code, flag information, and CCW information of the transfer count are extracted from the buffer (512) (step 605). Next, the command code is analyzed (Step 606). If the command code is a control command, the command frame information of the control command is passed to the control processor, and the parameters in the buffer are transferred by extension to the data transfer control unit (530). ) To the control processor (540) (step 607). On the other hand, if the result of analyzing the command code is a WRITE command, after passing the WRITE command frame information to the control processor (540), the actual data in the buffer is extended by the data transfer control unit (530). ) Under the control of the control processor (540).
(550) (step 608). Next, a process of receiving the transfer completion status of the parameter / actual data from the control processor is executed (step 609). next,
The flag information in the buffer previously fetched is determined (step 610), and if the command chain flag is on, the process of acquiring CCW information from the buffer (step 60)
Return to 5). If the command chain flag is off, a process of issuing a status frame is executed as channel control (step 611), and the process proceeds to a conventional process. Through the above processing, the CCW can be separated.

FIG. 7 uses the embodiment described with reference to FIGS. 3 to 6 and, on the ESCON interface, DX / LOC /
FIG. 7 shows a sequence diagram when WRKD is executed. First, the CPU issues a command frame (CMD) indicating that the CCW chains have been combined (70).
1). Next, a command response frame (CMD RE) indicating that the combined command has been received from the DKC side.
SP) is issued (702). Next, a command response reception frame (ACTT CMD RESP) indicating that the command response has been received is issued from the CPU side (703). Next, the command side, the command code of the DX command, the LOC command, and the WRCKD command, the flag, the transfer count, and the CCW list in which the actual data are stored are issued as the data frame (DATA) (704). Next, a status frame (STUS) indicating that the data frame has been received and processing according to the CCW chain in the data has been completed is generated by the DK.
Issued from the C side (705). Next, a status reception frame (ACPT STUS) indicating that the status frame has been received from the CPU side is issued (7).
06). Next, from the DKC side, a device level ACK frame (DEV AC
K) is issued (707).

In the case of a CCW chain for executing WRITE of a plurality of records, the present embodiment employs a format in which CCWs of a plurality of records are arranged in a CCW list in a data frame. That is, for example, “WRCKD... Of the CCW list stored in the data buffer 334 of FIG.
.. WR data ”are arranged in plurality. It is possible to change the method of creating the CCW list by changing the location (402) of the command code analysis determination in FIG. In the example, DX command and LOC
Commands are combined, but no READ-related commands are combined after this combination. Therefore, DX /
The LOC join command is sent alone to the DKC side, and DX,
The READ command following the LOC is also sent to the DKC side alone, and the DX / DXC interface
It looks like a READ-related command chained to the LOC connection command. As a result, it is possible to reduce the overhead until the actual data transfer is started, as compared with the conventional operation as shown in FIG.

[0019]

The data processing system of the present invention has a CPU
Side, the CCW chains are combined, a plurality of CCWs are collectively transferred to the DKC, and the DKC side separates and processes the CCW chains, whereby a plurality of CCWs between the CPU and the DKC are processed.
The overhead can be reduced by the communication. CPU-D
When the physical transfer speed between the KCs is further improved, the performance can be improved by reducing the overhead.

[Brief description of the drawings]

FIG. 1 is a diagram showing an overall configuration of a data processing system of the present invention.

FIG. 2 is a diagram showing a sequence on a conventional ESCON.

FIG. 3 is a diagram for explaining coupling of CCW chains on the CPU side.

FIG. 4 is a diagram illustrating a flowchart of a process of combining CCW chains on the CPU side.

FIG. 5 is a diagram illustrating separation of a CCW chain on the DKC side.

FIG. 6 is a diagram illustrating a flowchart of a process of separating a CCW chain on the DKC side.

FIG. 7 is a diagram showing a sequence on ESCON according to the present invention.

[Explanation of symbols]

 101 Central Processing Unit (CPU) 102 Disk Control Unit (DKC) 103 Disk Drive Unit (DKU) 104 CPU-DKC Connection Cable 105 DKC-DKU Connection Cable 111 Arithmetic Processing Unit (IP) 112 Main Storage Unit (MS) 113 Input / output control unit (CH) 114 System controller unit (SC) 121 Channel control unit (CH control unit) 122 CACHE memory unit (CACHE) 123 Control processor unit 124 Data transfer control unit 131 Disk device

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Noboru Koumi 2880 Kozu, Odawara-shi, Kanagawa F-term in Storage Systems Division, Hitachi, Ltd. (Reference) 5B014 EB04 GB07 GB08

Claims (4)

[Claims] An arithmetic unit for executing a program / processing data, a main memory for storing a program / data, and an input / output for controlling data transfer between the main memory and an external disk controller. In the data processing system having a channel unit, the input / output channel unit combines a plurality of channel command words (hereinafter, referred to as CCW) to create a CCW list, and adds a command frame including a CCW combined command to the CCW list. And a means for transferring the data to the disk controller. 2. The data processing system according to claim 1, wherein the CCW in the CCW list maintains the format of the original CCW. 3. A control processor for managing data in a disk controller, a cache memory for storing data, and a channel control unit for controlling data transfer between the cache memory and an external data processing system. In the disk control device, the channel control unit may control the data processing system
When a CCW list in which a plurality of CCWs combined with a command frame including a CW combination command is transferred is transferred, means for separating each CCW in the CCW list and processing each separated CCW are provided. A disk control device characterized by the above-mentioned. 4. A data processing system comprising a central processing unit and a disk controller connected to the central processing unit, the central processing unit comprising: an arithmetic unit for executing a program / processing data; A main storage device for storing programs / data, and an input / output channel unit for controlling data transfer between the main storage device and the disk controller;
The input / output channel unit connects a plurality of CCWs to
Means for creating a list, adding a command frame containing a CCW binding command to the CCW list, and transferring the command frame to the disk control device. The disk control device includes a control processor for performing data management and the like, and a device for storing data. And a channel control unit for controlling data transfer between the cache memory and the central processing unit. The channel control unit receives a command frame including the CCW connection command from the central processing unit. A data processing system comprising: means for separating each CCW in the CCW list when the transferred CCW list is transferred, and processing the separated CCWs.