JPH0414154A - Virtual storage control system - Google Patents

Abstract

PURPOSE:To shorten the paging processing time and at the same time to reduce the capacity f an auxiliary storage by outputting the compressed page contents to the auxiliary storage when a page-out operation is carried out. CONSTITUTION:A compression information setting part 4 receives a report of a page-out subject page and reads the information on the page out of a main storage 1. Then the part 4 compresses the information and searches for an unused part of an auxiliary storage 2 by reference to an auxiliary storage control part 6 to output the compressed information. When a page fault interruption occurs, a memory restoring part 5 refers to a page table 7 to serach for the storing position of the storage 2 for the page having a page fault. Then the part 5 reads out the stored compressed information and restores this information to output it to an idle page frame of the storage 1. Thus it is possible to reduce the quantity of input/output data to the storage 2 having a low processing speed compared with the internal processing speed of an electronic computer system. Then the paging processing time is shortened and at the same time the capacity of the storage 2 is reduced.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a virtual memory management system in an electronic computer system.

[Conventional technology]

In the conventional virtual memory management method, in which virtual storage is divided into pages and the main memory is divided into page frames of the same size as the pages, frequently used pages are stored in the main memory and used. When a page to be paged out is selected during the periodic monitoring process for storing infrequent pages in the auxiliary storage device, the information of the selected page is transferred directly to the auxiliary storage device consisting of a disk device and a drum device. I try to go out. Furthermore, when a page fault occurs, the page is directly paged in from the auxiliary storage device to the main storage device.

[Problem to be solved by the invention]

In the conventional virtual memory management method described above, when performing paging, the information on the page is paged out as it is, so there is a problem that paging takes time and a large capacity auxiliary storage device must be prepared. There was also.

An object of the present invention is to shorten the time required for paging and to reduce the capacity of an auxiliary storage device.

[Means to solve the problem]

In order to achieve the above object, the present invention provides a computer system that includes a main storage device and an auxiliary storage device, a virtual storage area is divided into page units, and the main storage device is divided into page frame units. a management means for managing the usage status of the auxiliary storage device and the storage location of the page in the auxiliary storage device; and upon being notified of the page to be paged out, information on the page to be paged out is transferred from the main storage device. compression information setting means for reading and compressing the information, searching for an unused portion of the auxiliary storage device by referring to the management means, and outputting the compressed information to the found unused portion of the auxiliary storage device; When an interrupt occurs, the storage location of the page where the page fault has occurred is searched for in the auxiliary storage device by referring to the management means, and the compressed information stored in the found storage location is converted to the original information. and memory restoring means for restoring the data to a free page frame of the main storage device.

[For production]

The usage status of the auxiliary storage device and the storage location of the page in the auxiliary storage device are managed by the management means. For example, the management means manages the usage status of the auxiliary storage device by dividing the auxiliary storage device into blocks smaller in size than a page, and managing the usage status of each block, and the block number of the block that outputs the page is The storage position of the page in the auxiliary storage device is managed by managing the page in number correspondence.

When a page to be paged out is notified through periodic monitoring processing or the like, information on the page to be paged out is read from the main storage device by the compression information setting means and compressed.

After that, the management means is referred to by the compression information setting means,
An unused portion of the auxiliary storage device is found, and compressed information is output to the found unused portion.

Furthermore, when a page fault interrupt occurs, the memory restoring means refers to the management means and searches for the storage location in the auxiliary storage device of the page where the page fault has occurred. Thereafter, the compressed information stored in the found storage location is restored to the original information and output to an empty page frame of the main storage device.

〔Example〕

Next, embodiments of the present invention will be described in detail with reference to the drawings.

FIG. 1 shows a block 1 of an embodiment of the present invention, which includes a main storage device 1 divided into page frames of the same size as a page, an auxiliary storage device 2 consisting of a disk device, a drum device, etc. A loader 3 loads a program from a program library (not shown) to the main storage device 1, and an auxiliary storage device 2 compresses the information of the page to be paged out.
When a page fault interrupt occurs, the compressed information setting unit 4 pages out the page, and when a page fault interrupt occurs, restores the compressed information of the page stored in the auxiliary storage device 2 to the original information and fills the empty page frame in the main storage device l. It is composed of a memory restoration section 5 for page-in, an auxiliary storage management section 6, and a page table 7.

FIG. 2 is a diagram showing a configuration example of the auxiliary storage device 2. As shown in the figure, the auxiliary storage device 2 includes a plurality of blocks BO, Bl, B2. It is divided into... 1
The size of one block (unit block length B) is smaller than the page length P of one page, and is defined by the following equation (1).

B=P+N (1) However, N is a value such that the unit block length B is an integer.

Therefore, for example, if the page length P is 4096 and N is 8, the unit block length B will be 512 bytes.

FIG. 3 is a diagram showing an example of the configuration of the auxiliary storage management unit 6, and each block BO, Bl of the auxiliary storage device 2.

... block number 31 and each block BO, Bl.

In this embodiment, the corresponding in-use bit indicates that "block 11 is in use,"
A block of 0'' means that it is unused. Therefore, the example in FIG. 3 means that block BO is in use and block B1 is unused.

FIG. 4 is a diagram showing an example of the configuration of the page table 7,
A page number 41 and a page frame address 42 indicating the address on the main storage device 1 of the page frame where the page is stored.
and existence bit 43 indicating whether the page exists on the main storage device 1 (in this embodiment, “1” = existence, “O” =
= absent) and auxiliary storage device 2 where the page is stored
It consists of block number 44 above. In the example in the figure, the page with page number PO is at address A of main storage device 1.
This shows that the page with page number PL is stored in block Bj of the auxiliary storage device 2.

FIG. 5 is a flowchart showing an example of processing by the compression information setting unit 4;
! ! l is a flowchart showing an example of processing by the memory restoration unit 5;
The operation of this embodiment will be explained below with reference to each figure.

In FIG. 1, when the loader 3 is requested to execute a program, the loader 3 loads the requested program from the program library into an empty page frame of the main storage device 1, and loads the requested program from the page frame address 42 of the page table 7 and the existence bit. Update 43. Thereafter, control is transferred to the program execution start address, and program execution is started.

When the compression information setting unit 4 is notified of a page to be paged out through conventional periodic monitoring processing, it starts the process shown in the flowchart of FIG. (Step 551) Next, the compression information setting unit 4 calculates the number of blocks required to output the compression information from the length of the compression information and the unit block length B, and further reads it from the auxiliary memory. By referring to the management unit 6 and finding the blocks whose in-use focus is "0" for the number of blocks mentioned above,
Select a block to output compressed information (step 55
2). Now, for example, if the length of the compressed information is 3000 bytes,
Assuming that the unit block length B is 512 bytes, the number of blocks required to output compressed information is "6", and six blocks whose in-use bit is "0" are selected.

Next, the compression information setting unit 4 sequentially outputs the compression information compressed in step 351 to the block selected in step S52 (step 553).
updates the contents of block number 44 corresponding to the page to be paged out in page table 7 to the block number of the block that outputs the compression information (step 554). At this time, if compression information is output to multiple blocks, Writes the block number in the order in which the information was output.Next, the compression information setting unit 4 sets the presence bit 43 of the page table 7 corresponding to the page to be paged out to indicate the page fault status (Step 555), and then the process is terminated. For example, the page to be paged out is page number P.
If the compressed information obtained by compressing the contents of the page is output to blocks Bn and Bm, in step S54, the contents of the block number 44 corresponding to the page number Pn of the page table 7 are output to Bn and Bm. An updating process is performed, and in step S55, a process is performed to update the existence bit 43 corresponding to the page number Pn of the page table 7 to "0".

Further, when a page fault interrupt occurs due to the absence of a page in the main storage device 1 during program execution, the memory restoration unit 5 starts the process shown in the flowchart of FIG. 6, and first refers to the page table 7. , obtains the block number of the auxiliary storage device 2 in which the compressed information of the page where the page fault has occurred is stored (step 561).

Next, the memory restoring unit 5 reads the compressed information from the auxiliary storage device 2 according to the block number obtained in step S61 (
step 562). If a plurality of block numbers are obtained in step S61, the memory restoring unit 5 reads the compressed information in the order stored in the page table 7.

Next, the memory restoration unit 5 restores the compressed information read in step 362 and pages it into an empty page of the main storage device 1 (step 563), and then performs auxiliary storage management corresponding to the block read in step S62. The in-use focus of section 6 is set to "0" (step 564). Next, the memory restoration unit 5 sets the address of the page frame into which the restoration information has been paged in to the page frame address 42 of the page table 7 corresponding to the page where the page fault occurred (step 565), and further sets the address of the page frame in which the restoration information is paged in. Existence focus 43 of table 7 is “1”
(Page fault release letter Li) Next step 566
), then the process is completed.

〔Effect of the invention〕

As explained above, the present invention compresses the contents of the page before outputting it to the auxiliary storage device when page-out is performed, which reduces the processing speed compared to the internal processing of a computer system. Since the amount of input/output data to the slow auxiliary storage device can be reduced, the paging processing time can be shortened compared to conventional methods, even considering the time required for data compression and restoration processing. This also has the effect of reducing the capacity of the auxiliary storage device.

[Brief explanation of drawings]

Fig. 1 is a block diagram of an embodiment of the present invention, and Fig. 2 is an auxiliary storage device! 3 is a diagram showing an example of the configuration of the auxiliary storage management section, FIG. 4 is a diagram showing an example of the configuration of the page table, and FIG. 5 is a flowchart showing an example of the processing of the compression information setting section. , FIG. 6 is a flowchart showing an example of processing by the memory restoring unit. In the figure, 1... Main storage device, 2... Auxiliary storage device, 3... Loader, 4... Compression information setting unit, 5...
-Memory restoration unit, 6...Auxiliary storage management unit, 7...Page table.

Claims (2)

[Claims] (1) In a computer system that includes a main storage device and an auxiliary storage device, a virtual storage area is divided into page units, and the main storage device is divided into page frame units, the usage status of the auxiliary storage device and , a management means for managing the storage position of the page in the auxiliary storage device; and upon being notified of the page-out target page, reads out and compresses the information of the page-out target page from the main storage device; compression information setting means for searching an unused portion of the auxiliary storage device by referring to a management means and outputting the compressed information to the found unused portion of the auxiliary storage device; The storage location of the page in which the page fault has occurred in the auxiliary storage device is found by referring to the management means, and the compressed information stored in the found storage location is restored to the original information and the information is restored to the main storage. A virtual memory management method comprising: memory restoration means for outputting to a free page frame of a device. (2) The management means manages the usage status of the auxiliary storage device by dividing the auxiliary storage device into blocks whose size is smaller than a page and manages whether each block is in use. 2. The virtual memory management system according to claim 1, wherein storage positions of pages in said auxiliary storage device are managed by managing block numbers of output blocks in correspondence with page numbers.