JPH0512125A - Address conversion system - Google Patents

Abstract

PURPOSE:To save address space by sharing a same block in a virtual address space among plural processes without one-sidedly releasing the common block of address conversion information when one process ends. CONSTITUTION:With respect to a software module stored in the virtual address space, module information 105 using the common number of processes which share the module as a module entry is provided. Address conversion information 101 using as its entry a block No. in the virtual address space, block No. in an actual address space having a size equivalent to the size of the block, the common number of processes sharing the block in the virtual address space, is also provided. The common number of the module entry is copied to the common number of address entries, the common number of the modules are increased/decreased by the increase/decrease of the number of processes utilizing the module, and when the common number becomes zero when the process utilizing the module does not exit, the address entry is also erased.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an address conversion system, and more particularly to an address conversion system for a virtual memory system of an information processing system.

[0002]

2. Description of the Related Art Conventionally, this type of address translation system manages address translation information in which a block number of a block in a virtual address space and a block number of a corresponding block in a real address space are held as address entries. Means and address translation information management means, and an address entry including this block number is searched from the address translation information management means by the block number of the block in the input virtual address space.
The presence or absence of the corresponding address entry is determined, and if the corresponding address entry exists, the address translation control unit that reads or writes information from the entry, and the address entry read by the address translation control unit. It has a real address calculation means for obtaining a real address from a block number of a block in the real address space and a virtual address.

[0003]

In the conventional address translation system described above, the address translation information management means holds the block number of the block in the virtual address space and the block number of the corresponding block in the real address space. Even if multiple processes share the same block in the virtual address space, the state is not held by the address translation information management means, so a block shared by other processes is required. Even in such a case, the shared block may be released when one of the shared processes ends, and the address translation information of the block may be lost from the address translation information management means. Therefore, even if multiple processes require exactly the same module, it is necessary to allocate the same module to the virtual address space by the number of processes that require it, which consumes more address space than necessary. There is a point.

[0004]

According to the address translation method of the present invention, for a certain software module stored in a virtual address space divided into blocks of a fixed length, its module name and The starting block number, the number of processes sharing this software module, and the number of blocks occupied by this module are set as one module entry, and the module entry corresponding to each software module stored in the virtual address space is held. The module information management means and the module information management means are searched for a module entry including this module name based on the addition of the module entry and the software module name, and the presence or absence of the corresponding module entry is determined. Module to Module information control means for reading or writing the module entry when the entry exists, a block number of a block in the virtual address space and a size equal to the corresponding block in the virtual address space. The block number of the block in the real address space and the number of processes sharing the block in the virtual address space are regarded as one address entry, and this address entry is a block in the virtual address space which the virtual address has. Address translation information management means for holding the address translation information corresponding to the number of the address translation information, and the address entry is added to the address translation information management means, and the address translation information is added by the block number of the block in the input virtual address space. Address including this block number from the management means Find the entry,
Address conversion control means for determining the presence or absence of the corresponding address entry, and reading or writing the entry if the corresponding address entry exists,
The address translation control means is configured by including a real address calculating means for obtaining a real address from the block number of a block in the real address space of the address entry read by the address translation control means. The history of use of each block in the space is held, and when all the blocks in the real address space are occupied, by the information of the number of processes sharing the block held by the address translation information management means and the use history, And a block discriminating means for selecting a block to be saved or removed from the real address space.

[0005]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, the present invention will be described with reference to the drawings.

FIG. 1 is a functional block diagram of an embodiment of the present invention. The block diagram of FIG.
The address translation information management unit 2, the address translation information control unit 3, the real address calculation unit 4, the module information management unit 5, and the module information control unit 6 are connected to the central processing unit 9 via a common bus 8, and A real address output line 7 extends from the real address calculating means 4.

FIG. 2 is a diagram for explaining the operation of the block diagram of FIG. 1. The address translation information management means 2 stores the book number of the block in the virtual address space as shown in the address translation information 101 of FIG. Data of the format in which the block number of the block in the real address space corresponding to this and the number of processes sharing the block in the virtual address space are taken as one address entry is set as the number of blocks in the virtual address space. Correspondingly holds. The module information management means 5 stores the software module name, its start block number, and the number of blocks occupied by the module as one module entry data in the virtual address space as shown in the module information 105 of FIG. It holds corresponding to each individual software module.

The central processing unit 9 starts a process,
Consider a case where it is necessary to allocate the software module A107 to the virtual address space. Central processing unit 9
Inputs the module name into the module information control means 6 via the common bus 8 to search the module information 105 of the module information management means 5. Module A
If 107 is not assigned to the virtual address space, the module entry of the module A 107 is not registered in the module information 105. In this case, the central processing unit 9 searches the address information management means 2 via the address conversion control means 3 and checks whether the number of continuous blocks required by the module A 107 can be secured. If possible, the central processing unit 9 adds a module entry to the module information management means 5 via the module information control means 6, and this module entry is occupied by the module name, the starting block number of the previously secured block, and the module. Register the number of blocks you have. At this time, since the number of processes using the module A is one, the shared number of processes in this module entry is set to 1. Further, the central processing unit 9 transfers the shared number of this process to the shared number of blocks of all address entries corresponding to this module of the address information management means 2 via the address conversion control means 3. The range to be transferred can be easily obtained from the block start number and the number of blocks in this module entry of the module information management means 5. On the other hand, if the module A107 is already assigned to the virtual address space, the module information 1
The module entry of the module A107 is registered in 05. At this time, since the module A107 may be shared, it is not necessary to newly secure a block in the virtual address space. The central processing unit 9 increases the sharing number of the process in the entry of the module A107 in the module information managing unit 5 by one through the module information controlling unit 6, and further sets the sharing number of this process to the address translation control unit 3. It is transferred to the shared number of blocks of all address entries corresponding to this module of the address information management means 2 via.

The central processing unit 9 refers to the contents of the module A 107 by using the virtual address 100. In this embodiment, as shown in FIG. 2, the virtual address 100 is a block number that designates a block in the virtual address space in the upper portion, and the lower portion is an offset that designates a word in the block.

The central processing unit 9 inputs the virtual address 100 to the address conversion control means 3 via the common bus 8.
The address translation control means 3 searches the address translation information management means 2 for an address entry including this block number based on the higher block number of the input virtual address. If the real block number in the real address space 103 exists in the address entry, this block is assigned to the real address space, and therefore the address translation control means 3
Retrieves the block number of the corresponding real address space 103 from this entry and transfers it to the real address calculation means 4. The real address calculating means 4 obtains the real address 102 by setting this block number as the upper order and the offset in the virtual address 100 as the lower order, and outputs it from the real address output line 7. The central processing unit 9 uses the real address 102 to refer to the contents of the module A 107 in the real address space. On the other hand, during the address entry, the real address space 103
If the above real block number does not exist and all blocks in the real address space 103 are not allocated to the virtual address space, the central processing unit 9 allocates a block in the proper real address space 103, and The block number is registered in the corresponding address entry in the address translation information management means 2. If all the blocks in the real address space 103 or any block in the virtual address space are allocated, it is necessary to remove any of the blocks or save them in the auxiliary storage device. At this time, the central processing unit 9 makes an inquiry to the evacuation block discriminating means 1 about a block to be removed or evacuated. The evacuation block determination means 1 holds the usage history of each block in the virtual address space. Based on the usage history and the number of processes sharing the block in the address entry held by the address translation information management unit 2, the save block determination unit 1 determines the block with the smallest number of shared blocks and the oldest unused block. Select and notify the central processing unit 9. Further, when the software module A107 becomes unnecessary due to the termination of the process, the central processing unit 9 searches the module information management means 5 via the module information control means 6 and shares the process in the entry of the module A107. Decrement the number by 1. As a result, if the number of shared processes becomes 0, there is no need to allocate it to the virtual address space, so the module information management means 5 deletes the module entry of this module.

On the other hand, after the above operation, if the number of shared processes is 1 or more, the number of shared processes corresponds to this module of the address information management unit 2 via the address conversion control unit 3. Transfer to the shared number of blocks of address entry.

[0012]

As described above, according to the present invention, since the address translation management information holds the shared number of processes sharing a block in the virtual address space, there is a process using a certain block. However, it is possible to prevent the situation where the block is removed. Therefore, the same software module can be shared by a plurality of processes, the storage area can be saved, and the blocks that are shared by the fewest processes can be saved / removed, so that the reading and writing of the actual block to the auxiliary storage device is reduced. effective.

[Brief description of drawings]

FIG. 1 is a functional block diagram of an embodiment of the present invention.

FIG. 2 is a diagram for explaining the operation of the embodiment of FIG.

[Explanation of symbols]

1 Evacuation block discrimination means 2 Address translation information management means 3 Address conversion control means 4 Real address calculation means 5 Module information management means 6 Module information control means 7 Real address output line 8 common buses 9 Central processing unit

Claims (2)

[Claims] 1. A process of sharing a module name, its starting block number, and this software module with respect to one software module stored in a virtual address space divided into blocks of a fixed length. The number of modules and the number of blocks occupied by this module are regarded as one module entry, and module information management means for holding module entries corresponding to individual software modules stored in the virtual address space, and module information management means On the other hand, the module entry including this module name is searched by the addition of the module entry and the software module name, the presence or absence of the corresponding module entry is determined, and if the corresponding module entry exists, the module entry Module information control means for reading from or writing to the memory, a block number of a block in the virtual address space and a block in the real address space having a size equal to the corresponding block in the virtual address space Block number and the number of processes sharing the block in the virtual address space are set as one address entry, and this address entry is held in correspondence with the number of blocks in the virtual address space of the virtual address. Address translation information management means, the address entry is added to the address translation information management means, and the block number of the block in the input virtual address space is included from the address translation information management means. Search for an address entry and search for that address entry. If there is a corresponding address entry, the address translation control means for reading or writing the entry and the address entry read by the address translation control means for the block in the real address space An address conversion method comprising: a real address calculating means for obtaining a real address from a block number and a virtual address. 2. The address translation method according to claim 1, wherein the history of use of each block in the virtual address space is held, and when all blocks in the real address space are occupied, the address translation information management means An address translation method comprising: a block discriminating unit that selects a block to be saved or removed from an actual address space based on information on the number of processes sharing a held block and the usage history.