JPH03262059A - Real memory allocating system - Google Patents

Abstract

PURPOSE:To prevent a device from being stopped with the occurrence of parity error and to improve the operating ratio by providing a virtual memory system with a stand-by alternative allocation memory to adopt the real memory allocating system where re-allocation is executed by the occurrence of parity error. CONSTITUTION:An alternative allocation memory 6 with each page as a unit is prepared on a main memory (real memory) 1; and if parity error occurs, an alternate allocation part 3 allocates the program, which is stored in the page frame where parity error occurs, on the alternate allocation memory 6 to rearrange it, and the program is run from the stop time. Thus, the processing is continued without stopping the device operation even when parity error occurs.

Description

[Detailed Description of the Invention] [Summary] The present invention relates to a method for allocating real memory, and aims to avoid operation stop processing due to parity errors. A memory for parity allocation is provided, and an alternate allocation section that reallocates the page-by-page program located in the corresponding real memory when a parity error is detected and starts the alternate allocation memory. The configuration is such that when an error occurs, the corresponding page-by-page program is relocated to alternate allocation memory and processing is continued.

[Industrial application field]

The present invention relates to an improved method for allocating real memory in a virtual memory system.

In a computer system that loads a program into main memory and executes it, when a parity error occurs, the operation of the device is stopped after error processing such as error information output.

For this reason, the system cannot be restarted unless the real memory in the area where the parity error has occurred is replaced, which lowers the operating rate of the system.

The same is true for virtual memory systems, and there is a need for a real memory allocation method that allows processing to continue without stopping the device even if a parity error occurs.

[Prior art and problems to be solved by the invention] In a computer system that loads a program into main memory and runs the program to perform a predetermined process, parity pits are added to the program and then loaded into the main memory. , a parity check is performed at the time of reading to ensure data reliability.

If a parity error occurs during this parity check and the parity error still occurs even after retrying, it is diagnosed as an abnormality in the main memory, and the computer is stopped after displaying the error information.

After this, after replacing the relevant part of the main memory, the program will be run again.

As described above, when an abnormality occurs in the main memory, conventionally, the device has to be stopped and the hardware needs to be replaced, resulting in a problem that the operating rate of the device decreases.

In view of the above problems, it is an object of the present invention to provide a real memory allocation method in a virtual memory system that allows processing to continue without stopping the operation of the device even if a parity error occurs.

[Means to solve the problem]

In Figure 1 - Configuration diagram of the embodiment, 6 is memory for alternate allocation, 3 is alternate allocation section, and when a parity error is detected, the page-by-page program located in the corresponding real memory is alternated. The allocation is rearranged in the memory 6 and activated.

[For production]

A memory 6 for alternate allocation in page units is prepared on the main memory (real memory), and when a parity error occurs, the alternate allocation part 3 is used to store the program stored in the page frame where the parity error occurred. The alternate allocation is for memory 6
, and then run the program from the moment it stopped.

As described above, even if a parity error occurs, processing can be continued without stopping the operation of the apparatus.

〔Example〕

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

FIG. 1 is a block diagram of one embodiment, and FIG. 2 is a diagram showing an example of the execution process of a user program.

In FIG. 1, 1 is a main memory (real memory) in which an operating system OS such as a memory management unit 2 resides, and a load area for a user program 7 is divided into page frames 5 and managed.

A memory management unit 2 allocates a page frame 5 to each page of the user program 7 and starts the program.

Reference numeral 3 denotes a replacement allocation section, which is provided in the memory management section 2, and performs replacement allocation processing upon notification of occurrence of a parity error.

Reference numeral 4 denotes a page table, and the allocation of the user program 7 is used for the previous management, and in the illustrated example, the page numbers ① to ① of the user program 7 are associated with the storage frame addresses.

Reference numeral 6 indicates a memory for alternate allocation, which is a spare page frame provided on the main memory. The address is registered together with the conventional page frame 5 in a page frame table (not shown).

A parity check section 8 performs a parity check on the data output on the bus, and issues an interrupt to the processor 9 when a parity error is detected.

9 is a processor that runs a program on the main memory 1.

With the above configuration, replacement allocation as shown in the example below is processed.

(1) The memory management section 2 allocates a page frame 5 to each page (1) to (2) of the user program 7 and loads the pages.

(2) The user program 7 is started.

(3) The user program 7 is executed in the order of ■→■→■→■.

(4) ■ If a parity error occurs during execution, an interrupt occurs, and after the error is displayed, the replacement allocation section 3 is activated.

Incidentally, when a parity error occurs again after a retry, the replacement allocation section 6 may be activated.

(5) Relocate ■ to memory 6 for alternate allocation, and (■.

) After updating page table 4, start ■゛.

At this time, the state at the time the parity error occurs is saved in the processor 9, and the processor 9 reads this content and starts up from the time the parity error occurs.

(6) Execute the following steps.

As described above, when a parity error occurs, the spare replacement allocation can be reallocated to the memory 6 and processing can continue, so there is no need to stop the operation of the device, and if a parity error occurs while the device is inactive. Just replace the memory.

〔Effect of the invention〕

As explained above, the present invention provides a method for allocating real memory in a virtual memory system by providing a spare memory for alternate allocation and reallocating it when a parity error occurs. Since there is no need to stop the system, it has the effect of improving the operating rate.

[Brief explanation of drawings]

FIG. 1 is a block diagram of one embodiment, and FIG. 2 is a diagram showing an example of the execution process of a user program. In the figure, l is the main memory, 2 is the memory management section, 3 is the alternate allocation section, 4 is the page table, 5 is the page frame, 6 is the alternate allocation memory, 7 is the user program, and 8 is the parity check section. , 9 is a processor. Figure 1 Figure 2

Claims (1)

[Claims] In a virtual memory system that allocates real memory in page units, there is provided a memory for alternate allocation (6), and a program in page units that is placed in the corresponding real memory when a parity error is detected. and a replacement allocation unit (3) that is activated by rearranging the program in the replacement allocation memory, and when a parity error occurs, the corresponding page-by-page program is relocated to the replacement allocation memory and processing is performed. A real memory allocation method characterized by continuity.