JPS6394350A - Memory managing system in on-line system - Google Patents

Abstract

PURPOSE:To reduce overhead in a memory management, by securing a desired memory area on a first actual memory device for a transaction processing, and loading a job program required for the said trasnsaction processing. CONSTITUTION:The memory area (number of pages) required for the execution of the job program on the actual memory device is decided first. And when it is decided that the said job program is also not loaded on a main memory device according to a memory managing table, the job programs of the said page being loaded until then for desired number of pages in which an effective bit represents '0', are purged to an auxiliary memory device 11. And a required job program is loaded on the said page from a program library 12. At this time, a loaded job program ID is stored in the corresponding page entry of a memory managing table, and also, a flag '1' which represents the effective bit, is set.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a memory management method for an online system.
Especially in online systems using virtual memory,
The present invention relates to a memory management method suitable for loading a business program that processes transactions into a real storage device.

[Conventional technology]

Conventionally, when operating a virtual memory computer system in an online environment, memory management has been performed independently of transaction processing by business programs. That is, the usage status of each page of the real storage device is monitored, and when a page replacement request occurs, for example, the so-called LRU (LRU)
During transaction processing, which is a characteristic of online systems, the business program that processes the transaction uses a large amount of real storage, and when the transaction ends, the page to be replaced is determined by the page to be replaced. No consideration was given to the fact that it would be unnecessary from the perspective of the equipment.

Regarding memory management using conventional virtual memory methods, please refer to Nikkei Electronics Books, "General Purpose Large Computers" (Nikkei McGraw-Hill Publishing, May 31, 1982), Vol.
It is described on pages 53 to 161 and pages 181 to 188.

[Problem that the invention seeks to solve]

In the conventional technology, consideration has been given to the fact that in online systems, business programs that process transactions use a large amount of real storage while processing one trunk transaction, and are no longer needed on the real storage device when the transaction is completed. As a result, page faults occur frequently during transaction processing, and a large amount of real storage is required for program loading, increasing the processing overhead of memory management and deteriorating the response performance of the online system. There was a problem.

An object of the present invention is to suppress the processing overhead of memory management and improve the response performance of an online system.

[Means for solving problems]

The present invention employs virtual storage control in which a business program is loaded into a real storage device when control is handed over at the beginning of trunk processing, and is excluded from page replacement, and is made into a page replacement target when trunk processing ends.

[Operation] The memory area required for business programs that process various trunk transactions is secured in the real storage device when control is passed to the business program at the beginning of trunk execution 3, and the business program is loaded from the program library. do,
The page will not be replaced. Thereafter, the memory area of the business program secured at the end of the transaction is targeted for page replacement. As a result, it is possible to suppress the increase in the storage capacity of the real storage device as much as possible, and to suppress memory management overhead during trunk deletion processing.
Improves responsiveness of online systems.

〔Example〕

An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 shows an example of the configuration of an online system according to the present invention. The computer 10 includes an auxiliary storage device 11 for realizing virtual storage, a program library 12 in which business programs and online control programs exist, a terminal system 13 used for online processing, and a database 14.
is connected. The electronic computer has a real storage device (main memory), and in addition to an online control program that performs trunk deduction control based on input from the terminal system 13, and a business program that performs trunk deduction processing, it also has a memory for business programs. A management table exists.

Figure 2 shows an example of the structure of the memory management table.
Each page of the real storage device includes identification information (business program ID) of the business program existing on the page, and a validity bit indicating whether the business program on the page is not to be replaced. For example, if the business program on the relevant page is to be replaced, the validity bit is “
0", and "1" if not applicable.

FIG. 3 is an example of a transaction processing flow of the online system according to the present invention. Message input from the terminal system 13 causes transaction processing. The online control program performs trunk processing schedule processing to determine the business program to be started based on message input. Next, the memory area (number of pages) on the real storage device required to execute the business program is determined. Then, according to the memory management table, if the relevant business program does not yet exist on the main storage device, the previous business program of the page is stored in the auxiliary memory for the desired number of pages whose validity bit indicates 0''. After expelling the page to the page 11, load the required business program from the program library 12 to the page. At this time, it is effective to store the loaded business program ID in the corresponding page entry of the memory management table. Set the gender bit to "'1'".

Next, control is passed to a business processing program to perform business processing.

After various requests are made to the online control program during business processing, such as referencing and updating the database 14, outputting to the terminal system 13, and overlay loading of the business program, control is returned to the online control program when the business process ends. . The online control program sets the validity bit of the corresponding page entry in the memory management table to "0" and targets the page where the business program that is no longer needed is stored, and then updates the database 14 and sends the page to the terminal system 13. Performs trunk processing termination processing such as outputting messages.

According to this embodiment, since the memory area necessary for loading a business program can be secured in real storage, the processing overhead of program loading is reduced.

〔Effect of the invention〕

As explained above, according to the present invention, by securing a desired memory area on the first real storage device for trunk ablation processing and loading a business program necessary for the trunk ablation processing, memory management overhead is reduced. This has the effect of improving the response performance of the online system by minimizing the increase in real storage capacity.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing an example of the configuration of an online system according to the present invention, FIG. 2 is a diagram showing an example of the contents of a memory management table, and FIG. 3 is a diagram showing an example of the processing flow of trunk redemption according to the present invention. . 10...Electronic computer, 11...Auxiliary storage device,
12...Program library, 13...Terminal system, 14...Database. Figure 1 Figure 2 Memory 1t\-T-Full Figure 3

Claims (1)

[Claims] (1) In a virtual memory-based online system, a business program that performs transaction processing is loaded into the real storage device when control is passed at the beginning of the transaction processing, and is excluded from replacement, and is targeted for replacement at the end of the transaction processing. A memory management method for an online system characterized by the following.