JPH02238546A - Control processing system for input/output device - Google Patents

Abstract

PURPOSE:To shorten the overall average time for input/output of data by accepting plural input/output requests via an input/output device. CONSTITUTION:An input/output device 1 contains a magnetic disk device 5, a cache memory 7 which shortens the input/output time of data, and a controller 6 which controls the device 5 and the memory 7. Plural devices 1 are controlled by an input/output control part 2. A single device 1 accepts plural input/output requests and at the same time executes one or two input/output requests in parallel with each other. Therefore a multi-request accepting part 61 is added to the controller 6 together with a next request processing part 62 which processes the prescribed one of plural accepted input/output requests. The part 62 performs its process in parallel with the input/output request that is presently carried out by the device 1. Thus the input/output time of data is shortened in a state where the data is stored in the memory 7.

Description

[Detailed Description of the Invention] [Summary] Regarding the control processing method of an input/output device having a cache memory, the purpose of this invention is to shorten the input/output time of data when the data exists in the cache memory. A request identification code is added to the control program, and a request identification code processing section for identifying the input/output request by this is provided in the control program,
The controller is provided with a multiple request receiving unit that accepts a plurality of the input/output requests, and a next request processing unit that processes a predetermined input/output request among the plurality of input/output requests, and the control program individually identifies the request. A plurality of input/output requests are issued to the input/output device to which the code is attached, and while a certain input/output request is being executed in the input/output device, the multiple request reception unit accepts another input/output request. A plurality of input/output requests are received, the next request processing unit processes the other input/output requests, and the controller notifies the control program of completion of execution of the input/output request together with the request identification code. Configure.

[Industrial application field]

The present invention relates to a control processing method for an input/output device, and more particularly to a control processing method for an input/output device having cache memory.

In the input/output device 6, a cache memory is provided in order to shorten data input/output time. for example. A cache memory is provided in the magnetic disk device. When data exists in the cache memory (has been cached), seek time and rotational wait time are omitted, making access time extremely short.

[Conventional technology]

FIG. 4 is an explanatory diagram of the prior art, showing the state of conventional input/output control.

In Figure 4. 1 is an input/output device, and 2 is an input/output control unit.
3 is a control program, 5 is a magnetic disk device, 6 is a controller, 7 is a cache memory, 9 is %ill '+
This is a wholesale tape.

The illustrated input/output device I is basically a magnetic disk device 5.
It further includes a cache memory 7 for shortening data input/output time and a controller 6 for controlling these. A plurality of input/output devices 1 are managed and controlled by an input/output control section 2. One input/output device 1 can normally execute (accept) only one input/output request at a time.

Therefore, the control program 3 handles multiple input/output requests R issued from multiple tasks. I to R2:l are serialized (queued) for each input/output device W1.

For this purpose, the 2 control program 3 includes a control table 9, creates a queue of input/output requests for each of the input/output devices DISKO to DISKn, and manages them. The control program 3 is the input/output request R placed at the head of the queue. , and R2 are executed by the corresponding input/output devices DISKO and DISK2 via the input/output control unit 2. Then, as soon as these processes are completed, the control program 3 sends the input/output request R that is placed at the head of the queue. 2 and R22.

[Problem to be solved by the invention]

According to the prior art described above, when the input/output device 1 has the cache memory 7 as shown in the figure, the purpose of providing the cache memory 7, which is to shorten the data input/output time, is significantly lost.

for example. In the illustrated input/output request RO2, the input/output device D
Assume that the data to be read from ISKO exists on the cache memory 7.

However, for the input/output device DI SKO, the input/output request R from another task is first received. 1, the corresponding input/output request R until this is completed. 2 cannot be executed. And input/output request R. Suppose that the data related to 1 does not exist on the cache memory 7. When executing the input/output request Ri, a seek operation, a rotation waiting operation, etc. are included. Therefore. I/O request R. Considering 2, even though the data exists on the cache memory 7. The input/output time for that data becomes long.

SUMMARY OF THE INVENTION An object of the present invention is to provide an input/output device control processing method that reduces data input/output time when data exists on a cache memory.

[Means to solve the problem]

Figure 1 is a diagram showing the principle structure of the present invention. 1 shows a data processing device according to the invention;

In Figure 1, 1 is an input/output device, 2 is an input/output control unit,
3 is a control program. 31 is a request identification code processing unit; 4
is the main memory, and 5 is the magnetic disk device. 6 is a controller, 61 is a multiple request reception unit 62 is a next request processing unit, and 7 is a casonyu memory 18 is a request management table.

The input/output device 1 basically consists of a magnetic disk device 5, and further includes a cache memory 7 for shortening data input/output time. It has a controller 6 for export. A plurality of input/output devices 1 are managed and controlled by an input/output control section 2. One input/output device 1 receives multiple input/output requests and executes one or two input/output requests in parallel.

For this purpose, the controller 6 includes a multiple request receiving unit 61 that accepts multiple input/output requests, and a next request processing unit 62 that processes a predetermined input/output request among the multiple input/output requests received by the multiple request receiving unit 61. provided. Next request processing unit 62
The processing by . This is performed in parallel with the input/output request currently being executed in the input/output device 1.

The control program 3 specifies one input/output device W1 and issues multiple input/output requests to the input/output device W1 to the input/output control unit 2. The input/output control unit 2 sends an input/output request to the designated input/output device 1.

The control program 3 is provided with a request identification code processing section 31 for adding a request identification code to each of these issued input/output requests. The request identification code processing unit 31
In addition, an input/output request is distinguished from other input/output requests by the request identification code added to it.

[For production]

The control program 3 makes a plurality of input/output requests Rot, Ro2, and R to one input/output device 1 (discussed as DISKO) to the input/output control unit 2. , are issued in this order.

A request identification code is attached to each input/output request. The input/output control section 2 is . Multiple input/output requestsROII RO
2. Send RO3 to the input/output device DISKO in sequence.

The input/output device D I SKO has its multiple request reception unit 61
The first input/output request R. , and execute it.

Here, in the input/output request Rot, the input/output device iDrsK
Assuming that the data to be read from o does not exist on the cache memory 7, the magnetic disk device 5 is accessed by the controller 6 for execution. That is, a seek operation for execution and a rotation wait operation are performed.

Input/output request R at input/output device D I SKO. While executing I, control program 3 issues another input/output request RO2. The input/output device iDIsKo via the input/output control unit 2
send to The multiple request accepting unit 61 of the input/output device DISKO accepts this input/output request RO2. In other words, the multiple request receiving unit 61 is configured to accept requests from other input/output requests (Rot) while executing a certain input/output request (Rot) in the input/output device 1 (DISKO).
) by accepting. Enables acceptance of multiple input/output requests.

The next request processing unit 62. The multiple request receiving unit 61 receives the other input/output request R. 1 if 2 is accepted The other input/output request R. Processing for 2 is performed. Here, input/output request R. Assume that the data to be read from the input/output device DISKO in step 2 exists on the cache memory 7. Reading of the data, ie, input/output request R. 2 is executed. Therefore, the top of the queue and the next I/O request R. I+R. 2 are executed in parallel. I/O request R. 2 is executed during the seek time and/or rotation waiting time when executing the input/output request Rot, so there is no problem.

The controller 6 is. Controller 6 or next request processing unit 6
Input/output request R by 2. 1 or R. When the execution of step 2 is completed, the control program 3 is notified of this. The notification of completion of this execution is as follows. This is done together with the request identification code that was added when the input/output request related to the notification was issued. Therefore, the control program 3 makes an input/output request R. Even if the notification of the completion of execution of step 2 is received earlier than that of the input/output request ROI, the request identification code will not be processed. You can see which I/O requests have completed.

As described above, according to the present invention, the input/output time for an input/output request for which data exists on the cache memory 7 can be shortened.

〔Example〕

The data processing apparatus shown in FIG. 1 will be further explained.

The control program 3 and the input/output control unit 2 together constitute an I/O supervisor. When the control program 3 receives a request from the user for processing regarding the input/output device 1, it issues an SIO (start J/O) command as an input/output request to the input/output control unit 2, requesting execution of the channel program. do. Input/output requests. All are received, managed, and controlled by the input/output control unit 2. The input/output control unit 2 causes the control program 3 to generate an input/output interrupt for an input/output request that has been completed by the input/output device 1. Notify completion of the execution. At the time of an SIO command and an input/output interrupt, predetermined information including a request identification code is exchanged between the control program 3 and the input/output control unit 2 according to a predetermined ink face described later.

King memory 4 is the result of executing an input/output request. Input/output device 1
It stores data read from the magnetic disk device 5 or cache memory 7 and transferred via the input/output control unit 2. The main memory 4 is. It also stores predetermined information including a request identification code for its delivery.

The controller 6 performs necessary control to execute input/output requests. For example, when data related to an input/output request does not exist in the cache memory 7 but exists in the magnetic disk device 5, the magnetic disk device 5 is accessed to read the relevant data. Furthermore, if data related to the input/output request exists on the cache memory 7, the data is read from there.

The read data is transferred to main memory 4. The controller 6 also causes the input/output control section 2 to generate an input/output interrupt when the execution of the input/output request is completed.

When requesting this input/output interrupt, it is necessary for the controller 6 to notify the input/output control section 2 of the request identification code of the input/output request that has been completed.

For this purpose, the controller 6 includes a request management table 8, and holds a request identification code for each received input/output request.

The input/output control unit 2 activates the specified input/output device 1 immediately upon receiving an SIO command, and immediately generates an input/output interrupt upon receiving a request for an input/output interrupt. In addition. The input/output control unit 2 may include the request management table 8 and pass the request identification code to the input/output device 1.

FIG. 2 is an explanatory diagram of the input/output interface.

The interface for the Sl○ command is as shown in FIG. 2(A).

The SIO instruction is issued by the control program 3 and consists of an instruction code and a device address register number. Six device addresses are stored in the device address register in advance by the control program 3 to indicate which input/output device 1 is to be used.

Furthermore. When issuing an SI○ instruction, the control program 3 moves the main memory 4 to a predetermined location corresponding to the SIO instruction (
A channel program address (CAW) and a request identification code are stored in a fixed area). The channel reflex program address is. It shows where in the main memory 4 the channel program (CCW) to be executed by this SIO instruction is stored. The request identification code is information stored by the request identification code processing unit 31 for identifying an input/output request.

on the other hand. The input/output control unit 2 refers to the device address register indicated by the device address register number in the received instruction and learns the device address. Also, if the received command is s
Because it is an r○ command. The input/output control unit 2 (or controller 6) refers to a predetermined location corresponding to the SIO command on the main memory 4 and learns the channel program address and request identification code.

The input/output control unit 2 passes the channel program address and the request identification code to the input/output device 1 specified by the device address, and causes the input/output device 1 to execute the input/output request. The controller 1/roller 6 of the input/output device 1 that has accepted this input/output request stores the channel program address and request identification code in the request management table 8 upon acceptance.

The interface at the time of input/output interruption is as shown in FIG. 2(B).

The input/output interrupt (signal) is issued by the input/output control unit 2 that receives a request from the input/output device 1.

When each input/output interrupt is issued, the input/output control unit 2
A predetermined position M corresponding to the relevant input/output interrupt on the main memory 4
(fixed area). A request identification code and a channel status word (CSW) are stored. In addition, input/output interrupt old PSW (program status word) is also stored on the main memory 4. The request identification code is read from the request management table 8 by the controller 6 and notified along with the input/output interrupt request. It is stored in the same location as the interface of the SlO instruction. The channel status word consists of a status part and a maximum CCW address. The input/output interrupt old PSW consists of a mask status, an interrupt code including a device address, and an IA (instruction address) interrupt address.

On the other hand, the control program 3 that generated the input/output interrupt refers to a predetermined location corresponding to the input/output interrupt in the main memory 4 and learns the request identification code, channel status word, and input/output interrupt old PSW. That is. The request identification code processing unit 31 determines which input/output request has been completed based on the request identification code. Also, the extent to which the input/output request has been executed can be determined from the 5 channel status word.

Then, based on the input/output interrupt old PSW, the state returns to the state when the SIO instruction was issued.

Note that the request identification code 5 on the main memory 4 in FIGS. 2 (A) and (B) is not actually the code itself, but indicates the address of the code in the table (not shown) in which the code is stored. It will be done like this.

FIG. 3 is an input/output control processing flow.

(2) An SIO command, that is, an input/output request, is issued from the control program 3 to the input/output control section 2 through the interface shown in FIG. 2(A). At this time, the request identification code processing unit 31 stores the request identification code for the input/output request in the main memory 4.

The input/output control unit 2 passes the input/output request to the designated input/output device 1.

The controller 6 of the designated input/output device W1 accepts the input/output request through its multiple request accepting unit 61.

That is, the channel program address and the request identification code are retrieved from a predetermined location in the main memory 4, and stored in the request management table 8.

■ The controller 6 fetches the channel program on the main memory 4 based on the channel program address. Then, the controller 6 checks whether or not there is an error in the fetched channel program, and if there is an error, performs error processing.

(2) If there is no error, the controller 6 checks whether data to be continuously output by the channel program exists in the cache memory 7 (cache hint).

■ If it does not exist, the controller 6 connects the magnetic disk device 5 in order to access the magnetic disk device 5.
Check whether it is running.

If it is not in operation, the controller 6 starts up the magnetic disk device 5 and reads data.

At this time, a seek operation and a rotation wait operation are performed.

If it is in operation, another input/output request that was accepted earlier is being executed, so the controller 6 registers the input/output request in the queue.

(2) If the cache memory 7 exists, the controller 6 checks whether the cache memory 7 is under control (transferring data with the magnetic disk device 5 or the main memory 4) in order to access the cache memory 7.

When not under control 1 The controller 6 starts reading data from the cache memory 7, that is, data transfer onto the main memory 4 (DMA transfer). The time required for this data transfer is usually sufficiently shorter than the transfer time and rotation waiting time.

When under control, controller 1 and roller 6. Register the input/output request in a queue.

■ When the execution of the input/output request is completed, the controller 6 stores the request identification code and channel status word in the main memory 4 as input/output interrupt information, and requests the input/output control unit 2 to issue an input/output interrupt. do. The request identification code is obtained from the request management table 8.

Based on this request, the input/output control unit 2 sends a message to the control program 3 using the interface shown in FIG. 2(B).
An input/output interrupt occurs.

■ Controller 6 checks queue 1 and if there is a registered input/output request. Regarding this, process ■Repeat the following.

The above process is. Each I/O request is done in parallel.

For example, in the input/output device DISKO, the input/output request R
. As for 1, it is assumed that the post-processing ■ of the processing ■ is performed. The time required for this process (2) is long as described above. This input/output request R. An input/output request R is made during the execution of process 1 for 1. If there is 2, it is the previous input/output request R. I/O request R after 7 in parallel with process 1 (■). After 2, processing ■ to ■ are performed.

After this, the relevant input/output request R. When process (2) is performed for 2, the input/output request RO2 is registered in the queue. on the other hand. I/O request R. Processing ■ is performed for 2 and the main memory 4
When the data is transferred to R, the third input/output request occurs. 2 is the first input/output request R. Completes execution earlier than 1. Even in such cases, the request identification code is used. It is possible to know which input/output requests have completed execution. I/O request R.

The process ``2'' regarding ``2'' is performed by the multiple request receiving unit 61, and the other processes ``2'' to ``2'' are performed by the next request processing unit 62. Note that it is actually an input/output request R. While the process 1 for 1 is being performed, the controller 6 takes advantage of the fact that the controller 6 is idle.

〔Effect of the invention〕

As explained above, according to the present invention, in the control processing of an input/output device having a cache memory, data is stored in the cache memory by enabling the input/output device to accept multiple input/output requests. Since the input/output time for the relevant data can be shortened when the cache memory exists on the computer, the effect of shortening the input/output time by providing a cache memory can be fully utilized. The overall average input/output time can also be reduced.

[Brief explanation of drawings]

FIG. 1 is a diagram showing the principle configuration of the present invention. FIG. 2 is an explanatory diagram of an input/output interface. FIG. 3 is an input/output control processing flow diagram. FIG. 4 is an explanatory diagram of a conventional technique. 1 is an input/output device, 2 is an input/output control unit, and 3 is a control program. 31 is a request identification code processing unit, 4 is a main memory, 5 is a magnetic disk device, 6 is a controller, 61 is a multiple request reception unit 1, 62 is a next request processing unit 5, 7 is a cache memory, and 8 is a request management table.

Claims (1)

[Claims] An input/output device (1) that has a controller (6) and a cache memory (7) and executes an input/output request, and a control that issues the input/output request to the input/output device (1). A request identification code processing unit (3) that adds a request identification code to the input/output request and thereby identifies the input/output request.
1) is provided in the control program (3), and includes a multiple request receiving unit (61) that receives a plurality of input/output requests, and a next request process that processes a predetermined input/output request among the plurality of input/output requests. (62) and the controller (6).
), the control program (3) issues a plurality of input/output requests to the input/output device (1), each of which has the request identification code added, and While executing an output request, the multiple request receiving unit (61) accepts the plurality of input/output requests by accepting another input/output request, and the next request processing unit (62) receives the input/output requests regarding the other input/output request. A control processing method for an input/output device, characterized in that the controller (6) notifies the control program (3) of completion of execution of the input/output request together with the request identification code.