JPS5914031A - Method for controlling input and output - Google Patents

Abstract

PURPOSE:To reduce the load of an I/O control program, by providing a function for deciding the contents of failure and whether the recovery of the failure is possible or not, to a data trasmission controlling part and an I/O controlling part. CONSTITUTION:An I/O ring bus transmission controlling part 128 detects an error at the data transmission between the controlling part 128 and an I/O station 145, and when the error can not be recovered, prepares status report information to a job processor 110. A retrial request for the transmission error is included in the information. An I/O controlling part 147 executes a control procedure inherent to an I/O device 150 and retrial at the time of error generation, discriminates error information which is conventionally processed by the I/O control program of the job processor, and when the retrial is possible as the result of the discrimination, returns the status information including the retrial request to the job processor 110.

Description

[Detailed Description of the Invention] The present invention relates to an input/output control method between a processing device and an input/output device in an electronic computer system, and in particular, an improved input/output control method when an abnormality occurs in the input/output operation. Regarding control method.

In current electronic computer systems, due to the development of computer hardware, especially microprocessors, the processing unit that executes programs and the input/output processor that integrates and controls various input/output devices are separated. and input/output processing are parallelized. In addition, the execution of retries when an input/output operation abnormality occurs is also implemented in hardware. In order to control input/output between the processing device and the input/output device including the input/output processor in such a computer system,
Logically, the following information is used.

(1) Procedures for starting and controlling the input/output device from the processing device (command type 1 issuing procedure and control information that defines the operation of the input/output device).

(2) Method for reporting results from the input/output device side to the processing device at the end of input/output execution Issuance procedure).

By the way, in the conventional input/output control method, the detailed information reported from the input/output device to the processing device by the procedure (2) above is analyzed by the input/output control program (software) in the processing device, and the input/output control It determines whether the operation has ended normally or not, and if it has ended abnormally, whether it can be recovered based on the cause of the abnormality, and if it is possible to recover, it determines the control procedure for the input/output device for recovery. Ta.

However, from a functional perspective, input/output data is processed by a processing device.
The data is transferred along the path from data transmission control unit to input/output device control unit to input/output device, and is reported to the processing device without distinguishing whether the abnormality was detected in the data transmission control unit or the input/output device control unit. .

The processing unit software must therefore perform this separation. Furthermore, regarding retry when it is determined that recovery is possible, in the case of the data transmission control unit, starting from the beginning of the transmission,
That is, a simple command retry may be sufficient, but in the case of an error in the input/output device control unit, the retry procedure differs for each input/output device.

For example, in the case of a data read error in a magnetic disk storage device, all you have to do is issue the data read command again.
A data read error in a magnetic tape device occurs because the part where the data to be read has already been recorded has run ahead of the read head. There must be.

Further, even in the same input/output device, different error causes may require completely different error recovery procedures.

For these reasons, the input/output control program on the processing device has become complicated, and a different program must be prepared for each input/output device. Therefore, as the system scale increases and the number of input/output devices increases, there are problems such as the input/output control program becomes large, the memory capacity for storing the program increases, and the overhead to run it increases. Ta.

The purpose of the present invention is to solve the problems of the conventional method described above,
An object of the present invention is to provide an input/output control method that reduces the load on input/output control program processing for input/output operation abnormalities and simplifies the program itself.

The present invention provides a data transmission control unit and an input/output control unit that perform input/output control and its abnormality detection with a function of determining the content of the abnormality and whether recovery from the abnormality is possible, and when it is determined that recovery is possible, processing is performed. A retry request that distinguishes the location of the error is reported in the input/output control end information to the device, and the input/output control program of the processing device responds to this retry request without determining the detailed information of the error. This feature is characterized in that it is possible to issue a retry command using a retry command, thereby reducing the burden on the input/output control program.

Hereinafter, the details of the present invention will be explained with reference to examples.

FIG. 1 shows an example of the configuration of a multiple processor system to which the present invention is applied. In the figure, a high-speed bus 105 is connected to a shared memory (MS) 100. Job Processor (JOBP
)110. File Control Processor (PCP)
) 120 and an input/output processor (IOP) 125 are connected. The file control processor 120 performs processing related to the file 130, and the input/output processor 125 connects a plurality of input/output devices (10
) 150 controls for interrogation. These processors 120 and 125 are referred to as dedicated processors. Job processor 110 handles user tasks and operating system functions other than dedicated processor functions.

FIG. 2 shows a simple functional block diagram of the input/output processor 125 and the input/output custition 145, which are involved in input/output control of the system of FIG. 1, and are equipped with means for implementing the method of the present invention. . In the figure, dotted arrows indicate control information, status information, data flow, etc. at input/output device activation commands and completion reports. The input/output processor 125 is roughly divided into the following three functional blocks: a high-speed bus interface control section 126, a device control command analysis section 127, and an input/output bus transmission control section 128. The high-speed path interface control unit 126 performs memory reading and writing to/from the shared memory 100 and interrupt control with the job processor 110, and the device control command analysis unit 127 interprets startup commands from the job processor 110. The input/output link bus transmission control unit 128 creates a message to be sent to the human output station 145, and sends device control information, input/output data, Sends and receives status information at the end of execution.

The input/output link bus control unit 128 is responsible for detecting transmission errors in data transmission with the input/output cassition 145, retry processing when such errors occur, and creating status report information for the job processor 110 when error recovery is not possible. This status report information includes:
A retry request for transmission errors, which is a feature of the method of the invention, is also included.

On the other hand, the input/output custition 145 can be roughly divided into the second functional block. In other words, the input/output link bus transmission control section 146 and the input/output control section 127 are operated by the input/output link bus transmission control section 146.
Device control information, input/output data, and status information at the end of input/output execution are exchanged with the input/output processor 125 via the input/output processor 40. The input/output control unit 147 drives the input/output device 150 based on the device control information received from the input/output link bus transmission control unit 146, and after completing the input/output operation, creates input/output status information, which is used for startup. The information is reported to the job processor 110 via the input/output link bus 140 along a route opposite to that of the command information, together with status information indicating the transmission control result created by the input/output processor 125. This input/output control unit 147 is variable for each connected input/output device 150, and in addition to the control procedure unique to the input/output device and retry in case of an error, conventional processing is performed by the input/output control program of the job processor. It also has the function of realizing the method of the present invention, in which the error information that has been sent is also determined here, and as a result, if a retry is possible, a retry request is included in the status information and returned to the job processor 110. .

In the above input/output control system, the entire input/output processor 125 and the input/output link bus transmission control unit 146 in the traffic control system 145 functionally constitute a transmission control unit, which is a type of input/output device 150. However, the input/output control section 147 corresponding to the input/output device control section has nine different functions for each input/output device 150 as described above.

Next, input/output control and the operation of the method of the present invention therein will be explained. However, when executing input/output control, job processor 1
The information passed between I/O processor 10 and I/O processor 125 is shown in FIG. 3 and is located on shared memory 100 and connected to a pointer corresponding to each I/O processor. The contents will be explained in order below.

FIG. 4 is a flowchart of the input/output activation processing program 2 (9) that the job processor has in its operating system. First, when an input/output control macro instruction is issued from a user task, this program is activated. Then, in steps 500 and 501, a command list 220 and a dedicated processor activation block 210 (FIG. 3) are created. Here, the block 210 consists of a pointer to the next input/output device, the number (logical address) and address (physical address) of the input/output device, the corresponding command list 220, and the addresses of the status report area 230, and the command list 220 is an input/output control command (distinction between pronunciation and honor), device control information (specifying line breaks, etc.), a data address and count indicating the address and length of the data transfer destination, and an input/output cap that specifies the terminal for process input/output, etc. It consists of Indian addresses, etc. Further, the status report area 230 will be described later. Now, returning to FIG. 4, in step 502, the status report area 230 is cleared, and in step 503, block 210 is connected to the control information pointer 200 for the input/output processor that controls the corresponding input/output device. ) Interrupts the input/output processor 125. Next, the state waits for the task that made the input/output request (step 504).
, the job processor moves on to other tasks.

Here, the aforementioned status report area 203, which is a feature of the method of the present invention, will be explained. Fifth
The figure shows an example of its configuration, which is divided into a status report area 2301 for input/output processors and a status report area 2302 for input/output devices. The sizes of these areas are the same regardless of the type of input/output processor or input/output device. Furthermore, the input/output processor status word PISW and the input/output status word DISW in each area have the same format regardless of the type of input/output processor or input/output device. However, valley area 2301, 20
The detailed information PE5W and DE8W in 32 are defined for each input/output processor and input/output device.

An example of the format of each status 11PIsW and DISW is shown in FIG.
It consists of processing requests for (11) 10 operating systems and information on the type of error indicating the result of determining the cause of the error within the own device.

Among these, processing requests to the operating system are expressed in the same way regardless of the input/output processor or input/output device.On the other hand, the processing requests to the operating system are specified for each error type, each input/output processor, and each input/output device, and the detailed information is Valley area 2
This is set in detailed information PBSW and DESW of 301.2302. The retry request (R, TYREQ), which is a feature of the present invention, is defined as one item of processing requests to the above-mentioned operating system.

Returning to the operation, the starting processing program for the input/output custition 145 in the input/output processor 125 shown in FIG. 7 will now be described. As explained with reference to FIG. 4, upon receiving an interrupt from the job processor 110, the program shown in FIG.
Activation block 21 on the shared memory 100 indicated by 00
0 and the command list 220 (created in steps 500 and 501 in FIG. 4), and in step (12) 701, these are analyzed to create information for driving the input/output device. In step 702, it is determined whether or not to write to the input/output device, and in the case of writing, in step 703, the write data is fetched from the shared memory 100 to the memory in the own device 125, and in step 704, the input/output cussion 145
Control information (created in step 701) and data are also sent to the input/output custition 145 when the request is made. In step 705, the occurrence of a transmission error is checked, and if there is no error, the process ends; however, if a transmission error occurs, the activation of the input/output custition 145 is repeated a predetermined number of times, and if there is still a transmission error, step 706
Then, the process moves to step 707.

In step 707, the job processor 110 in the input/output processor status PISW explained in FIG.
The retry request RTYREQ as a processing request for the input/output processor 125 is turned on in step 708, and the status information of the input/output processor 125 including this information is set in the status report area 2301 (13). A retry request for this transmission error may be a simple retry, so there is no need to analyze the cause of the error. In step 709, the activation block 210 that instructed the above processing is transferred to the voice/receiver 2 for the job processor.
05 to interrupt the job processor 110 and transfer the processing.

When it is determined in step 705 of FIG. 7 that there is no transmission error, input/output device control processing by the input/output custition 145 shown in FIG. 8 is performed.

That is, in step 800, various information is received from the input/output processor 125, and in step 801, control is performed for the input/output device 150 and data is received and received.

When it is determined in step 802 that the input/output control has ended, it is determined in steps 803 and 804 whether or not there was an error in the input/output device control this time, and whether or not it can be retried if there is an error. If there is an error and a retry is possible, a signal is created in step 805 to turn on the retry request in the input/output status word DISW.b0 If there is no error or a retry is not possible, the process moves directly to step 806. Step (14) Step 806 creates information to be sent to the input/output processor 125 by combining input/output operation completion information and data if necessary, and sends this information to the input/output processor 125 in step 807.
Transfer to. Note that the method for determining whether or not retry recovery is possible in step 804 is the conventional method of determining whether or not recovery is possible using an input/output control program.
This can be achieved by programming within 45.

The input/output processor 125 receives the signal from the input/output cusp and performs the completion reporting process shown in FIG. First, it is checked in step 901 whether or not there is an error in data transmission via the input/output ring bus 146 at the end of this process, and if there is an error, data reception is retried a predetermined number of times. If that does not work, move from step 902 to step 903, and repeat step 90 in the same way as step 707 in FIG.
At step 3, the retry requests RTYR and EQ in the input/output processor status word PISW are turned on, and the process jumps at step 908. When it is determined in step 901 that there is no transmission error, it is determined in step 904 whether or not there is an error in the input/output device operation (15), and if there is an error, step 907
If not, the read data is transferred to the shared memory 100 at the time of reading in steps 905 and 906, and the process moves to step 907. In step 907, all data transmission is normal (step 705 in FIG. 7 and step 901 in FIG. 9 are both determined to be normal), so information indicating normal transmission is set in the input/output processor status word PISW. The process then proceeds to step 908. In this case, the various information obtained through the above processing is set in the input/output processor status report area 2301, the startup block 210 that has completed the input/output processing is connected to the pointer 205 for the job processor, and the job processor 110
Interrupts.

Through the various processes described above, input/output control is returned to the job processor 110 again. That is, step 70 in FIG.
This is the time when a transmission error occurs from 9, and the process shown in FIG. 9 ends. In either case, an interrupt is applied to the job processor 110, and this interrupt (16) starts the program shown in FIG. 10 for processing the completion report within the screening system.

In this program, first, in step 1000, the activation block 210 in which the termination report has been reported is determined from the pointer 205, and the contents of the system status report area 230 are determined based on the status report area address contained therein. In step 1001, each status@pworksw and DI8W in the area 230 are taken out, and in step 1002, it is checked whether the retry request TY_EQ in the input/output processor status word PISW is on. If it's on,
Since this indicates that there was a transmission error, the job processor 110 retries in step 1003.
The command for input/output is reissued (repeat from FIG. 4) and the process ends. This process has the same content for any input/output processor 125 or input/output device 150, and is performed regardless of the type of error in the status language PISW or its detailed information. The error type and its details are transferred as maintenance information, and are displayed and used by out-of-office personnel when necessary (17).

If the retry request is not on in step 1002,
Next, in step 1004, this time the status word DIS
It is checked whether the retry request R'I'YREQ in W is on. If it is on, it means that an error has occurred that can be recovered by retrying, so start Sun. Step 10
If there is no retry request in either 02 or 1004, the process is returned to the task that requested the input/output (step 1006), its waiting state is released, and the process ends.

As is clear from the above embodiments, according to the present invention, the input/output control program for determining the detailed status information from the input/output control program of the job processor and determining whether or not to retry is possible. There is no need to prepare a processing program for the device, and only the retry request in the status uterus is required to determine whether a retry is possible. This has the effect of greatly reducing the program capacity and the overhead of this process in the operating system.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing an example of the configuration of a multiprocessor system to which the present invention is applied, FIG. 2 is a diagram showing the functional blocks and information flow of the input/output processor and the input/output custition, and FIG. 3 is a diagram showing the input/output control. An explanatory diagram of various information transferred between the job processor and the input/output processor,
FIG. 4 is a processing flowchart of the input/output startup processing program in the operating system, FIG. 5 is an explanatory diagram of the status report area that is reported at the end of input/output execution, and FIG. An explanatory diagram of input/output processor status words and input/output device status words characterized by
FIG. 7 is a processing flowchart for starting the input/output custition by the input/output processor, FIG. 8 is a processing flowchart for controlling the input/output device by the input/output custition, and FIG. 9 is a processing flowchart for receiving a completion report from the input/output custition by the input/output processor. (19) FIG. 10 is a processing flowchart of the input/output termination processing program by the operating system. 100... Shared memo 1c 110... Job processor, 125... Input/output processor, 145... Input/output custition, 150... Input/output device, 230...
- Status report area, DISW...I/O processor status language, DISW...I/O device status language, 几TThEQ...Retry request. Agent Patent Attorney Masami Akimoto (2o) 41st eye 2nd eye 3rd eye 4th eye 5th z3θ / Kaya g

Claims (1)

[Claims] 1. Through an input/output device control unit for driving and controlling the input/output device, and a transmission control unit for controlling and transmitting data between the input/output device control unit and a processing device including a memory, In the input/output control method for executing data input/output to the input/output device according to instructions from the processing device, each of the input/output device control section and the transmission control section is configured to perform input/output device control and transmission control. If there is a malfunction at the end of each operation, it is detected, it is determined whether the malfunction can be recovered by a retry from the processing device, and if recovery is possible, an individual retry request to the processing device is sent to the input/output control. An input/output control method characterized in that the input/output control method has a function of reporting to a processing device in a completion report, and the processing device immediately issues a required retry instruction upon receiving the retry request. .