JPH0477946A - Execution system for input/output channel program - Google Patents

Abstract

PURPOSE:To decrease a burden on a host system-side on an input/output program with much repetition by executing the input/output channel program on a disk controller-side in a closed state. CONSTITUTION:When software issues a program transfer instruction, an input/ output channel device 20 reads the input/output channel program and accompanied data from a main storage device 10 and transfers them to a disk controller 30. The disk controller 30 receiving the program transfer instruction stores the received input/output channel program and accompanied data in RAM 39. When software furthermore issues a program starting instruction, the disk controller 30 decodes the input/output channel program stored in RAM 39 and executes an operation as against a disk storage device 50. Thus, the burden on the host system-side can be avoided.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an input/output channel program execution method related to a disk storage device, and more particularly to input/output control related to a disk storage device that reduces the load on a host system.

[Conventional technology]

In the conventional method of executing this type of I/O channel program, the I/O channel device reads the I/O channel command from the main memory in response to a channel program start command from software, propagates it to the disk controller, and then writes it to the disk storage device. The data transfer involved was performed between the main storage device and the disk storage device in real time via an input/output channel device and a disk controller.

[Problem to be solved by the invention]

In a large-scale online system, input/output commands are usually executed frequently between an external storage device and a host, resulting in a high load state. In particular, input/output instructions that involve large amounts of data transfer are transferred via the system bus that connects the input/output channel device to the main storage device, etc., so when multiple input/output channel devices are working simultaneously, the system The data transfer capacity of the bus may be exceeded. As a result, some input/output instructions may have to wait for execution or need to be re-executed. In devices such as disk storage devices where the data transfer timing is specified, the data transfer timing must be determined anew by re-executing the input/output command.
At 600 rotations, the loss is approximately ie, 7 milliseconds). To avoid this, it is necessary to use a host system with sufficient data transfer capacity, but this is expensive.

In a large-scale system, a considerable number of disk storage devices are connected as external storage, and the increased load due to maintenance work on these devices cannot be ignored.

For example, even if only a small portion of the disk storage device is available for use at certain times, the remaining storage devices must be reserved as data buffers or spares so that they can be used at any time. Therefore, it is necessary to perform preventive maintenance to ensure that it is always usable. A typical example of this preventive maintenance is a read test of all records on the disk medium, which checks the operation of the disk medium and the disk storage device as hardware. Originally, it is desirable to avoid burden on the host system side for such preventive maintenance.

[Means to solve the problem]

In the input/output channel program execution method of the present invention, when software issues a program transfer command to an input/output channel device, the input/output channel device transfers the input/output channel program generated in the main storage device and the data accompanying it. The disk controller reads the program data as a series of data from the main memory and transfers it to the disk controller connected to it, while the disk controller that receives the program transfer command from the input/output channel device reads the program data as a series of data. It works to store the input/output channel program and accompanying data in RAM,
When software issues a program startup command, the I/O channel device simply propagates this command to the disk controller, which then decodes the I/O channel program stored in RAM to perform operations on the disk storage device. It is configured.

Furthermore, in the input/output channel program execution method of the present invention, the target track range for program execution is included in the program start command, instruction, or parameter of the input/output channel program, and the parameters are referenced and updated in the disk controller itself. It is configured to execute sequentially within the execution target range.

〔Example〕

Next, the present invention will be explained with reference to the drawings.

FIG. 1 is a block diagram showing one embodiment of the present invention. In FIG. 1, one embodiment of the present invention includes a main storage device 10,
An input/output channel device 20 connected via the system bus 12, a disk controller 30 connected to this input/output channel device 20, and this controller 30
In a host system including a disk storage device 50 connected to The device 20 is configured to read the channel program 11 stored in the main storage device 10 and supply it to the disk controller 30 for execution.

First, when the software issues a "program transfer command," the input/output channel device 20 transfers the "program transfer command" stored in the data buffer 22 from the system bus 12 under the response control of the system bus controller 21, as shown in the flowchart of FIG. The transfer command is decoded by the I10 microprocessor unit 24 and processing is determined. The I10 microprocessor section 24 transfers this "program transfer instruction" code and the address of the disk storage device 50 to the data buffer 2.
2 and sends it to the disk controller 30 via the I10 interface control unit 23 (step 80).
. Subsequently, the I10 microprocessor unit 24 transfers the main memory 1 given in conjunction with the "program transfer instruction".
The storage address of the input/output channel program 11 of F0 is stored in the command pointer 25 area in the control memory of the F0 microprocessor unit 24 (step 81).
, the contents of the command pointer 25 are transferred to the system bus control unit 2.
1 in the memory address register 26 to drive reading from the main storage device 10. System bus control section 2
1 reads information stored in the channel program 11 from the main memory 10 into the data buffer 22 using the address contents of the memory address register 26 as a start address.

Here, the instruction format of the input/output channel program will be explained. One instruction in the input/output channel program includes an instruction code (command), a flag containing information on whether or not to chain instructions, a data count that indicates the number of data to be transferred, and the main memory where the data is stored. Contains 10 memory addresses. The commands, flags, and data counts read into the data buffer 22 were stored in the I10 microprocessor unit 24. - Later sent to the disk controller 30 as data (
Step 82). The I10 microprocessor section 24 is
The read memory address is set as the start address in the memory address register 26, data corresponding to the data count is read from the main storage device 10, and the system bus controller 21. Data buffer 22. It is transmitted to the disk controller 30 via the I10 interface control unit 23 (step 83). The I10 microprocessor section 24 refers to the above flag to check whether a chain of commands is specified (step 84). If command chaining is specified, the contents of the command pointer 25 are incremented (step 85), and the processes from step 82 onwards are repeated for the next command. When there is no command chain specification, the processing of the "program transfer command" is terminated, and a termination interrupt is reported from the input/output channel device 20 to the software via the system bus 12.

Next, the processing on the side of the disk controller 30 that has received the "program transfer command" will be explained.

When the microprocessor section 37 decodes the "program transfer instruction" stored in the data transfer section 32 via the host interface control section 31, it sets an initial value in the address register 36 of the RAM control section 34, and transfers data from the input/output channel device 20. The received data is transferred to the data transfer unit 32.
It is stored in the program data area 40 of the RAM 3B through the RAM control unit 34. Address register 36 is RAM3
It is automatically incremented each time 9 is read or written.

In this way, the "program transfer instruction" is transferred to the main memory 1.
The input/output channel program contents and accompanying data in the channel program 11 area of 0 are ported to the RAM 39 of the disk controller 30.

Next, the activation and operation of the input/output channel program ported to the RAM 39 will be explained. When the software issues a "program start command", the input/output channel device 20 that received this sends the code of the "program start command" and the disk storage device address received along with the command to the disk controller 30, Wait for the completion report from the disk controller 30. The disk controller 30 performs processing according to the flowchart shown in FIG. When the microprocessor section 37 receives the "program start command", it initializes the program pointer 38 prepared in its own control memory and sets the start RAM address of the program data area 40 of the RAM 39 (
Step 90). The microprocessor unit 37 sets a value in the program pointer 38 in the address register 36 and sequentially issues commands from the program data area 40.

The flag and data count are read (step 91).

It then decodes the command code and branches to a routine specific to each command.

If it is a data transfer type command, the value of the program pointer 38 is incremented, the first RAM address where the data associated with this command is stored is set in the RAM address register 36, and the value of the data count is set in the RAM counter 35. (Step 93). If the command is of the search type, the data read from the disk storage device 50 and the data read from the RAM 39 until the RAM counter 35 is exhausted are compared in the data transfer unit 32, and the microprocessor unit 37 determines the result and branches. If the command is a read type, the data read from the disk storage device 50 is stored in the RAM counter 35 in the area of the RAM 39 given by the RAM address register 36.
Store data until it runs out. Conversely, if the command is a write type, the RAM address register 36 provides R.
Data is read from the area of the AM 39 until the RAM counter 35 is exhausted and transferred to the disk storage device 50 (step 94).

When the processing of this command is completed, the microprocessor unit 37 refers to the flag and checks whether a chain of commands has been specified. If there is none, a completion report is sent to the input/output channel device 20. When a chain of commands is specified, the microprocessor unit 37 increments the value of the program pointer 38 to match the RAM address where the next instruction is stored (
Step 98), repeat the processing from step 91 onwards.

As an example of maintenance work, when reading all records of a disk storage device, it is necessary to define a command so that the microprocessor unit 37 sequentially changes the cylinder number and track number parameters and executes a read type command. good. No load is generated between the host system and the host system during this read test.

Another example of maintenance work is checking whether the surface of a disk storage medium is good or bad by actually writing records and then reading them. At this time, the microprocessor section 37
may execute write type and read type commands by sequentially changing parameters such as cylinder number and track number, and transmit a completion report to the input/output channel device 20 when an error is detected or when all are completed.

In theory, this input/output channel program can be executed between regular business operations, and the effect on business operations can be ignored if the execution interval is appropriate.

〔Effect of the invention〕

As explained above, the present invention reduces the burden on the host system side regarding input/output channel programs that are repetitive by allowing the execution of the input/output channel programs themselves to be carried out in a closed manner on the disk controller side. effective.

Furthermore, porting the input/output channel program to the disk controller side has the side effect of providing versatility in terms of functionality.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing an embodiment of the present invention, FIG. 2 is a flowchart showing processing of a program transfer command, and FIG.
The figure is a flowchart showing the processing of a program startup command. DESCRIPTION OF SYMBOLS 10... Main storage device, 20... Input/output channel device, 30... Disk controller, 50... Disk storage device.

Claims (1)

[Scope of Claims] 1. When software issues a program transfer command to an input/output channel device, the input/output channel device transfers the input/output channel program generated in the main storage device and the accompanying data to the input/output channel device in a series. It works to read data from the main storage device and transfer it to the disk controllers connected under it, and on the other hand, the disk controller that receives the program transfer command from the input/output channel device receives it as a series of data from the input/output channel. It functions to cause the program and associated data to be stored in RAM, and when software issues a program startup command, the I/O channel device simply propagates this command to the disk controller, which then stores the I/O channel program stored in RAM. A channel program execution method that decodes and executes operations on disk storage devices. 2. A claim in which the target track range for program execution is included in the parameters of the program startup command or input/output channel program, and the disk controller itself references and updates the parameters to sequentially execute within the target range of execution. The input/output channel program execution method described in Section 1.