JPH0520246A - Asynchronous i/o dynamic priority changing system - Google Patents

Abstract

PURPOSE:To sharply improve a data processing speed by effectively utilizing a main storage device and shortening a data reading/writing time from/in a user program. CONSTITUTION:A data processing system provided with an external storage device 5, a main storage device 4, a control program 10 for using a part of the device 4 as an asynchronous I/O buffer 3 for the device 5 and storing data in the buffer 3, and an asynchronous I/O execution task 20 for executing the asynchronous I/O operation of the data in the buffer 3 from a main storage space to the device 5 includes also an asynchronous I/O data counter 7 for controlling the priority of the task 20, a priority control table 6 and a means for changing priority by means of the table 6.

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, and more particularly to a method of controlling the timing of asynchronous I / O processing in the system.

[0002]

2. Description of the Related Art Generally, a data processing system of this type includes an external storage device in addition to a main storage device, and uses a part of the main storage device as an asynchronous I / O buffer for the external storage device. There is. In this case, data is written to or read from the data asynchronous I / O buffer under the control of a control program that exchanges various requests and data with the user program. ing.

Further, when a write request is issued from the user program, the data is written from the asynchronous I / O buffer to the external storage device regardless of the data usage rate. As described above, in the conventional data processing system that accesses the external storage device by the asynchronous I / O method, the I / O operation to the external storage device is executed without considering the priority of the data.

[0004]

In other words, in the data processing system for accessing the external storage device by the asynchronous I / O method as described above, the I / O to the external storage device is
O is an asynchronous I / O execution task with a unique priority. Since I / O was being executed, data reuse and optimal access to external storage devices, etc. in the asynchronous I / O buffer in the system The efficiency of the data manipulation of is not considered. For example, there is a problem that the corresponding data is not found at the time when a data read request is issued from the user program, and the data is read again from the external storage device. Therefore, the technical problem of the present invention is that the main storage device can be effectively used,
An object of the present invention is to provide an asynchronous I / O dynamic priority change system that can shorten the data read / write time from a user program and dramatically improve the data processing speed.

[0005]

According to the present invention, an external storage device and a main storage device are provided, and a part of the main storage device is used as an asynchronous I / O buffer for the external storage device. A control program for storing data in a buffer and a data processing system for performing an asynchronous I / O operation from the main storage space to the external storage device by an asynchronous I / O execution task for the data in the buffer
There is provided an asynchronous I / O dynamic priority change system characterized by having priority control means for controlling the priority of the O execution task and means for changing the priority under the priority control means.

According to the present invention, the priority control means uses the data in the buffer by updating the count according to each data write request from the asynchronous I / O execution task and the control program. Asynchronous I / O dynamic priority change characterized by having an asynchronous I / O data counter for calculating a rate and a priority control table for controlling the priority of the asynchronous I / O execution task according to the contents of the counter The scheme is obtained.

According to the present invention, the asynchronous I / O execution task receives the write request from the asynchronous I / O execution task.
An asynchronous I / O dynamic priority change method is obtained in which a valid state is generated when valid data is generated in the O buffer, and data is written in the external storage device until there is no data in the asynchronous I / O buffer. .

[0008]

In the present invention, a part of the main memory is used as an asynchronous I / O buffer for the external memory. The control program stores the data in this buffer. On the other hand, the asynchronous I / O execution task performs an asynchronous I / O operation on the data in the buffer from the main storage space to the external storage device. The priority of this asynchronous I / O execution task is controlled by the priority control means, and the priority is changed by the means for changing the priority under this priority control means.

[0009]

Embodiments of the present invention will now be described with reference to the drawings.

FIG. 1 is a block diagram of an embodiment of the present invention. As shown in FIG. 1, the data processing system includes a control program 10, an asynchronous I / O execution task 20, a priority control table 6, an asynchronous I / O data counter 7, and a part of the main storage space which is asynchronous I / O. It is composed of a main storage device 4 used as an O buffer 3 and an external storage device 5.

FIG. 2 is a flow chart of a processing example of the asynchronous I / O execution task 20 shown in FIG.

Referring to FIG. 2 as well, the operation of the embodiment shown in FIG. 1 will be described. The control program 10 receives an asynchronous I / O in response to an input / output request from the user program 00.
Data input 1 and output 2 are performed in the buffer 3 to exchange data with the user program 00. At the time of this data input 1, the asynchronous I / O data counter 7 is updated.

Further, the asynchronous I / O execution task 20 writes data to the external storage device 5 separately from the user program 00 until there is no more data in the asynchronous I / O buffer 3. At this time, the asynchronous I / O data counter 7 is updated (S
6).

Specifically, as shown in FIG. 2, asynchronous I / O
The O execution task 20 enters a ready state when valid data is generated in the asynchronous I / O buffer 3, and the asynchronous I / O
The external storage device 5 is used until there is no data in the O buffer 3.
Write data to (S5, S7). The asynchronous I / O execution task 20 performing this processing changes the priority using the asynchronous I / O data counter 7 and the priority control table (S1, S2, S3).

The asynchronous I / O execution task 20 operates separately from the user program 00 and the control program 10, and dynamically changes the priority based on the usage rate of the asynchronous I / O buffer (S6). At this time, the priority corresponding to the buffer usage rate is searched from the priority control table 6 (S3).

By associating these things with each other, when the user program 00 issues a data write request due to data exchange between the user program 00 and the control program 10, the control program 10
Stores the data in the asynchronous I / O buffer 3, sets the asynchronous I / O execution task 20 in the ready state, and continues the data exchange with the previous user program. on the other hand,
Since the asynchronous I / O execution task 20 has been made ready by the control program 10, the asynchronous I / O buffer 3
The writing process is continued until the valid data in the external storage device 5 is exhausted. However, in order to perform this write processing at the optimum timing in the system, the asynchronous I / O execution task 20 and the control program 10 manage a counter for calculating the usage rate of the asynchronous I / O buffer, thereby managing the priority control table. Is used to control the priority of the asynchronous I / O execution task 20.

[0017]

As described above, according to the present invention,
Data is saved in the asynchronous I / O buffer when a write request occurs, and the actual writing is performed by another task. At this time, in order to effectively use the data in the asynchronous I / O buffer in the system. , Asynchronous I /
The priority of the asynchronous I / O execution task is controlled from the usage rate of the O buffer, and the data is written to the external storage device by dynamically changing it, so that the data can be reused and the external storage device can be controlled. By making appropriate access to the main memory, the main storage device can be effectively used, the reading and writing time of data from the user program can be shortened, and the processing speed of the data processing system can be dramatically improved. It is possible to provide an asynchronous I / O dynamic priority change system capable of performing.

[Brief description of drawings]

FIG. 1 is a block diagram of an embodiment of the present invention.

FIG. 2 is a flowchart of a processing example of an asynchronous I / O execution task of FIG.

[Explanation of symbols]

1 input 2 outputs 3 Asynchronous I / O buffer 4 main memory 5 External storage device 6 Priority control table 7 Asynchronous I / O data counter 00 User program 10 Control program 20 Asynchronous I / O execution task

Claims (3)

[Claims] 1. An external storage device and a main storage device, wherein a part of the main storage device is an asynchronous I / O for the external storage device.
A control program that is used as a buffer and stores data in this buffer, and a data processing system that performs asynchronous I / O operation from the main storage space to the external storage device by the asynchronous I / O execution task of the data in this buffer In Asynchronous I / O dynamic priority change, there is provided priority control means for controlling the priority of the asynchronous I / O execution task, and means for changing the priority based on the priority control means. method. 2. The asynchronous I / O dynamic priority change method according to claim 1, wherein the priority control means updates the count by each data write request from the asynchronous I / O execution task and the control program. Accordingly, it has an asynchronous I / O data counter for calculating the data usage rate in the buffer, and a priority control table for controlling the priority of the asynchronous I / O execution task according to the contents of the counter. Asynchronous I / O dynamic priority change method. 3. The asynchronous I / O dynamic priority change method according to claim 2, wherein the asynchronous I / O execution task generates valid data in the asynchronous I / O buffer when a write request is given. The asynchronous I / O dynamic priority change method is characterized in that data is written into the external storage device until the asynchronous I / O buffer is out of data.