JPH07152642A - Data area expansion system - Google Patents

Abstract

PURPOSE:To improve program performance by decreasing the frequency of a block input/output process which is generated when a block expanded on an external storage device is accessed. CONSTITUTION:In addition to blocks A and B stored in a basic memory 2, the external storage device 3 is stored with blocks C-E exceeding the capacity of the basic memory 2, A block management table 1 is used to manage the storage positions and update states of the blocks. When the block B in the basic memory 2 and the block C on the external storage device 3 are swapped, the block management table 1 of the block B is referred to and when the block B is not updated, the block C is read in the basic memory 2, but when the block B is not updated, the block C is read in the basic memory 2 after the block B is saved on the external storage device 3.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a data area expansion method for expanding a data area by utilizing an external storage device in addition to a basic memory in manufacturing a program which uses a large amount of data area.

[0002]

2. Description of the Related Art Conventionally, in manufacturing a program that uses a large amount of data area, since the storage capacity of a basic memory is limited, blocks exceeding that capacity are expanded to an external storage device. Then, when accessing a block expanded in the external storage device, the work area is used to replace or swap the block on the basic memory with the access block.

[0003]

In the above-mentioned conventional technique, in order to swap the block of the external storage device and the block of the basic memory, an unnecessary block in the basic memory is saved in the work area (saving processing). It is necessary to read necessary blocks from the external storage device into the basic memory (reading process) and store the blocks of the basic memory saved in the work area in the external storage device (storing process).

As described above, there is a problem that the block input / output processing occurs three times during the swapping and the overhead increases. Also, regarding the block input / output processing when the unnecessary blocks on the basic memory are not updated, the reduction of the number of times of processing is not considered,
As described above, block input / output occurs three times, and there is a problem in that improvement in program performance cannot be expected.

It is an object of the present invention to provide a data area expansion system in which the number of block input / output processes that occur when accessing a block expanded in an external storage device is reduced and the program performance is improved.

[0006]

In order to achieve the above object, according to the present invention, in a data area expansion system for expanding a data area of a program by utilizing an external storage device in addition to the basic memory, the storage of the basic memory is performed. A block exceeding the capacity is stored in an external storage device, and the same block as the block in the basic memory is stored in the external storage device,
When the first block in the basic memory and the second block in the external storage device are swapped, if the first block has not been updated, the second block is read into the basic memory. , If the first block has been updated, the first block is saved to a corresponding block position in the external storage device, and then the second block is stored.
Is read into the basic memory.

[0007]

In the external storage device, in addition to the blocks stored in the basic memory, blocks exceeding the storage capacity of the basic memory are stored. The block management table manages the storage location and update status of blocks. When swapping the first block of the basic memory and the second block of the external storage device, the block management table of the first block is referred to. If the first block has not been updated, the second
Read the block of into the basic memory. When the first block has been updated, the first block is saved in the external storage device and then the second block is read into the basic memory. In this way, in addition to the blocks that exceed the basic memory, the blocks in the basic memory are also expanded in the external storage device, so when accessing the blocks in the external storage device, the unused blocks in the basic memory are stored in the work area. A block of the basic memory is directly stored in the external storage device, because the process of saving to is unnecessary. Also, by referring to the block management table, it is possible to determine whether or not the block on the basic memory has been updated. Therefore, if the block is not updated at the time of swap, the block of the basic memory is saved to the external storage device. Processing is omitted,
The number of block input / output can be reduced.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be specifically described below with reference to the drawings. FIG. 1 is a diagram for explaining the basic principle of the present invention, showing a block expansion into a basic memory and an external storage device. In FIG. 1, reference numeral 1 is a block management table for managing the locations and states of each block expanded in a basic memory and an external storage device, 2 is a basic memory on the main storage device, and 3 is an external storage device such as a disk. It is a device.

Data is processed in block units, and the storage capacity of the basic memory 2 is set to 2 blocks for the sake of simplicity. Currently, there are 5 blocks to be processed (A
To E), and when the size exceeds the storage capacity of the basic memory 2, the processing block A is stored in the basic memory 2.
And B are stored and the block C exceeds the basic memory 2,
D and E are expanded in the external storage device 3.

Further, with respect to the blocks A and B on the basic memory 2, the same blocks A and B are expanded in the external storage device 3. Each block expanded in the basic memory 2 and the external storage device 3 is managed by the block management table 1 in the expanded position and state.

FIG. 2 is a system configuration diagram of the present invention.
1, 2, and 3 are the block management tables described above,
A basic memory and an external storage device, 4 refers to the block management table 1 to control the input / output of the block, C
It is a block input / output control unit provided in the PU.

FIG. 3 shows the configuration of the block management table 1. In the table, for all blocks, a basic memory existence flag 11 indicating whether a block exists in the basic memory and a basic memory update flag 12 indicating whether a block in the basic memory has been updated. , Position 13 on the basic memory, and position 14 on the external storage device are written.

FIG. 4 shows a processing flowchart of the present invention when swapping an unnecessary block on the basic memory and a block (necessary block) on the external storage device. The block input / output control unit 4 refers to the basic memory existence flag 11 of the block management table 1 and determines whether or not the necessary block exists in the basic memory 2 (step 10).
1).

If the required block exists in the basic memory 2, the processing is terminated, and if it does not exist, the block input / output control unit 4 searches for an unused block in the basic memory 2 (step 102). A known method such as LRU or FIFO may be used as a method of selecting an unnecessary block.

Next, the block input / output control unit 4 refers to the basic memory update flag 12 of the block management table 1 to determine whether or not the unused block has been updated (step 103). If the unused block has been updated, the unused block is saved to the external storage device 3 (step 104), and if it has not been updated, it is not saved. Then, the necessary blocks are transferred from the external storage device 3 to the basic memory 2
(Step 105).

Regarding the number of block inputs / outputs in this embodiment,
This will be described with reference to FIGS. FIG. 5 shows an example in which a block on the basic memory is updated. If there are blocks A and B on the basic memory 2 and the block B has been updated to the block B ′, it is necessary to replace it with the block B having the old content in the external storage device 3. Therefore, the block B ′ having new contents is saved in the external storage device 3 (saving process),
Since the necessary block C is read from the external storage device 3 into the basic memory 2 (reading process), as a result, the block input / output process occurs twice in the present invention.

FIG. 6 shows an example in which a block on the basic memory has not been updated. If the blocks A and B on the basic memory 2 have not been updated, the blocks similar to the blocks A and B are present on the external storage device 3, so there is no need to save them. Therefore, only the process of reading the required block C from the external storage device 3 into the basic memory 2 is required. As a result, in the present invention, the block input / output process is 1
It only needs to be done once.

According to this embodiment, the number of block input / output operations can be reduced to once or twice by expanding all blocks in the external storage device.

[0019]

As described above, according to the present invention, a block exceeding the storage capacity of the basic memory is stored in the external storage device, and the same block as the block in the basic memory is stored in the external storage device. Therefore, if the block in the basic memory is not updated, the save processing to the external storage device is not required, the number of block input / output can be reduced compared to the conventional one, and the program performance can be significantly improved. It is possible to improve.

[Brief description of drawings]

FIG. 1 is a diagram illustrating a basic principle of the present invention.

FIG. 2 is a system configuration diagram of the present invention.

FIG. 3 shows a configuration of a block management table.

FIG. 4 shows a processing flowchart of the present invention when swapping an unnecessary block on a basic memory and a block on an external storage device.

FIG. 5 is a diagram illustrating an operation of the present invention when a block on a basic memory is updated.

FIG. 6 is a diagram illustrating an operation of the present invention when a block on the basic memory is not updated.

[Explanation of symbols]

 1 block management table 2 basic memory 3 external storage device 4 block input / output control unit

Claims (1)

[Claims] 1. In a data area expansion method for expanding a data area of a program by using an external storage device in addition to the basic memory, a block exceeding the storage capacity of the basic memory is stored in the external storage device and the basic memory is used. When the same block as the block in the external storage device is stored in the external storage device and the first block in the basic memory and the second block in the external storage device are swapped, the first block is updated. If not, the second block is read into the basic memory, and if the first block is updated, the first block is saved to a corresponding block position in the external storage device, After that, the data area expansion method is characterized in that the second block is read into the basic memory.