JPS62259153A - Main storage management system - Google Patents

Abstract

PURPOSE:To avoid deterioration of performance of a computer system by storing storage contents even in a frame set in an area where the reference is impossible from an input/output controller of a main storage device and starting reproduction at said frame. CONSTITUTION:When a frame of an area 2b where the reference is possible from an input/output device 4 of a main storage device 2 is allocated to a frame 3b of a virtual storage device 3, a frame 2d is taken by force from a frame 3a as long as the area 2b is entirely allocated and no change is given to the contents A of the frame 2d already allocated to the frame 3a. Then the contents A are stored in an idle frame 2e of an area 2a where the reference is impossible from the device 4 of the main storage device 2 before the frame 2d is allocated again to the frame 3a. Then the frame 2e if kept unused is allocated to the frame 3a when the main storage device 2 delivers a request for allocation to the frame 3a. If the frame 2e is not available, an input operation is carried out through an external storage device 1 for reproduction of the contents A.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a main memory management method in a computer system that performs virtual memory control.

[Conventional technology]

FIG. 2 is a schematic diagram showing the structure of a conventional main memory management system, in which reference numeral 1 denotes an external memory device, which is divided into areas 1a of a constant size.

2 is a main memory device, which is divided into an area 2a that cannot be referenced from the input/output control device 4 and an area 2b that can be referenced from the input/output side #f device 4; It is divided into 2d.

3 is a virtual storage device, which is divided into each frame 3a, 3b of a certain size, and a main storage device! 2 frames 2e and 2d.

4 is input/output side #! ! It is.

Next, the operation of the conventional main memory management system shown in Fig. g2 above will be explained. When allocating a frame in area 2b that can be referenced from input/output control device 4 in main memory ji[12 to frame 3b in virtual memory bag (i13), if all areas 2b have already been allocated, the virtual memory 1
'! ! Frame 2d, which has already been allocated to frame 3a of i3, is selected and it is checked whether the content A of that frame 2d has been changed. If this content A has not been changed, since the same content as content A is stored in the area 1a of the external storage device 1, the frame 2d is taken from the frame 3a and reassigned to the frame 3b. Thereafter, when a request to allocate a frame in the main storage device 12 to the frame 3a occurs, the vacant frame 2C in the main storage device 2 is allocated and the original content is transferred from the area 1a of the external storage device 1 under input/output control. He had figured out a method to read and play the data through device 4.

[Problem that the invention seeks to solve]

In the conventional main memory management method as described above, the above 1fcd
When the number of frame re-allocation requests increases, input operations to reproduce the contents of area 1a of external storage device i1 into frames of main storage device 12 occur frequently, resulting in a decrease in performance in the computer system. There was a problem with that.

The present invention was made to solve such problems, and an object of the present invention is to obtain a main memory management method that can prevent performance degradation of a computer system.

[Means for solving problems]

The main memory management method according to the present invention makes it possible to play back from frames in the main memory VC by saving the contents even in frames in areas that cannot be referenced from the input/output control device of the main memory. It is.

[Effect]

In the main memory management method of the present invention, by reproducing content from frames in the main memory device instead of reproducing content from an area in an external storage device, it is possible to prevent performance degradation of the computer system.

〔Example〕

FIG. 1X1 is a schematic diagram showing the configuration of the above-mentioned 1'f principle system which is an embodiment of the present invention. In the figure, 1 is an external storage device, which is divided into areas 1a of a constant size. 2 is a main memory ftl, which is divided into an area 2a that cannot be referenced from the input/output control device 4 and an area 2b that can be referenced from the input/output control device 4, and each frame 2d of a certain size.

It is divided into 20 parts. Frame 2d is within the area 2b, and frame 2e is within the frame 2a. 3
is a virtual storage device, which stores each frame of constant size 3
&, 3b, and each frame 2 of the main storage device 2
d, 2e. 4 is an input/output control device.

Next, the operation of the main memory management system, which is an embodiment of the present invention shown in FIG. 1, will be explained. When allocating a frame in the area 2b that can be referenced from the input/output control device 14 of the main storage device 2 to the frame 3b of the virtual storage device 3, if the area 2b has already been allocated, the frame 3b of the virtual storage device 3 has already been allocated. Frame 2d, which has already been allocated to frame 3a, is selected and it is checked whether the content A of that frame 2d has been changed. If this content A is not changed, the above frame 2d is changed to the above frame 3a.
before snatching it from and reassigning it to frame 3b above.
Main memory of the above content A! [It is saved in an empty frame 2e in the area 2a that cannot be referenced from the input/output control device 4 of it2.] After that, the main memory f for the frame 3a is
When a frame allocation request for ct12 occurs, frame 2e previously saved in the main memory fC112
If frame 2e remains unused, frame 2e is assigned as is to the above request. Above frame 2
If no e remains, it is necessary to perform the input operation from the external storage device 1 as described above to reproduce the contents.

In the above embodiment, the case where there is a single virtual storage device 3 has been described, but there may be a plurality of virtual storage devices 3.

〔Effect of the invention〕

As explained above, the present invention improves the conventional main memory management method by changing the method of reproducing the original content from the external memory fcil by input operation to the method of reproducing it from the main memory device in the main memory management method. Compared to other methods, this method has an excellent effect of preventing a decline in the performance of the computer system.

[Brief explanation of drawings]

FIG. 1 is a schematic diagram showing the configuration of a main memory management system according to an embodiment of the present invention, and FIG. 2 is a schematic diagram showing the configuration of a conventional main memory management system. In the figure, 1...external storage location a, la, 2a. 2 b...area, 2...main storage, 2c, 2d
, 2e. 3a, 3b...Frame, 3...Virtual storage device, 4
...It is an input/output control device. In each figure, the same reference numerals indicate the same or equivalent parts.

Claims (1)

[Claims] Virtual memory control is performed, and the main storage device is divided into an area that can be referenced by the input/output control device and an area that cannot be referenced, and the contents of the area that can be referenced from the input/output control device are transferred to the external storage device through the input/output control device. In the computer system where the content is stored, if the content is also saved in an area that cannot be referenced from the input/output control device, and the content needs to be reproduced, the content saved in the area that cannot be referenced from the input/output control device A main memory management method characterized by playback.