JPH0944405A - Electronic computer system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electronic computer system capable of adding a disk cache without replacing the hardware constitution or operating system of the electronic computer system. SOLUTION: An operation control means 110 for controlling an electronic computer 103 provided with a magnetic disk storage device 102 connected to an input/output bus 101 is provided with the magnetic disk storage device control means 111 of the magnetic disk storage device 102 and a device control means retrieval table 113 for specifying the magnetic disk storage device control means 111 by a device number for the input/output request of an application processing means 112. Further, the disk cache composed of a memory device 120 provided with a volatile memory 121, a battery 122 for memory backup, a means 123 for confirming the charging state of the battery for volatile memory backup and a DMA controller 124 and a disk cache controller is added.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electronic computer system provided with a disk cache, and more particularly to an electronic computer system to which a disk cache can be easily added.

[0002]

2. Description of the Related Art A conventional method of controlling a disk cache system having a magnetic disk storage device and a cache memory is such that a cache memory is provided inside the magnetic disk storage device, and the cache memory control is for controlling the cache memory inside the same device. Controller, or the controller of the magnetic disk storage device itself, or a system such as installing a dedicated disk cache device with a control controller for cache control between the computer and the magnetic disk storage device. Mostly by means of wear technology.

Japanese Patent Application Laid-Open Nos. 63-067661 and 3-224045 relate to battery backup of a cache memory provided in a magnetic disk storage device and data integrity, and JP-A-63-257.
Japanese Patent No. 045 describes a battery backup of a cache memory in a device dedicated to a disk cache and data integrity, both of which relate to a hardware technology.

When a disk cache system is realized by software means, any one of a main memory, a non-volatile memory, and a volatile memory with a battery for power supply backup is used as a cache memory, and the cache memory and the magnetic disk are used. Writing / reading to / from the storage device is performed by a control program for the magnetic disk storage device.

[0005]

When the disk cache system is realized by hardware, a dedicated device is often added to result in an expensive system, and the magnetic disk storage device itself has a cache memory. In this case, the magnetic disk storage device conventionally used in the computer system must be replaced with a magnetic disk storage device that can use a cache memory.

When the disk cache system is realized by software means, there are the following drawbacks. When the main storage device is used as a cache memory, it is necessary to prepare a large-scale backup battery that can guarantee the power supply to the entire electronic computer system, resulting in an expensive system. Further, if the CPU itself writes / reads to / from the cache memory, there is a risk that the system, which has been an I / O neck for a so-called magnetic disk storage device in the past, becomes a CPU neck.

When the control program of the magnetic disk storage device is involved in the cache memory control, in the electronic computer system which uses the control program of the magnetic disk storage device which does not perform the cache memory control, the disk cache is used and therefore the cache is used. It must be replaced with an operating system that can be equipped with memory control.

[0008]

SUMMARY OF THE INVENTION An object of the present invention is to add software control means and a memory device having a power source backup battery and a volatile memory to a disk cache, thereby reducing the hardware cost and (EN) Provided is an electronic computer system which can add a disk cache by adopting a disk cache control means which can be easily incorporated without replacing the operating system.

Therefore, an input / output bus for connecting an input / output device including the storage device of the present invention and a magnetic disk storage device as a secondary storage connected to the bus are provided. Input / output request of magnetic disk storage device control means for controlling output, device control means for controlling devices identified by device numbers assigned to each of the input / output devices connected to the input / output bus, and application processing means A device control means search table that associates device numbers and device control means included in
In a computer system operated by an object-oriented operation control means including a means for activating a corresponding device control means by searching a device control means search table by a device number, a magnetic disk storage device for the secondary storage is provided. A volatile memory that is a cache memory, a battery that backs up the power of the volatile memory when the power is cut off, a means that detects the state of charge of the battery, and a data transfer between a main memory as a primary memory and the volatile memory. A memory device having a controlling DMA data transfer means and connected to the input / output bus; a memory device controlling means added to the operation controlling means for controlling input / output to the memory device; and an application processing means. From the input to the magnetic disk storage device from the Operating the memory device as cache storage of the magnetic disk storage device, transferring data from the cache storage to the magnetic disk storage device via the main storage device, and generating a trigger for the data transfer. And a disk cache control means added to the operation control means for controlling the disk cache.

[0010]

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

Referring to FIG. 1 showing a functional configuration of an embodiment of the present invention, a disk cache memory device 12 is shown.
0, the memory device 120 and the magnetic disk storage device 1
The operation of the electronic computer 103 having the input / output bus 101 for connecting 02 is controlled by the operation control means 110. Operation control means 110
Includes a magnetic disk storage device control means 111 for controlling input / output of the magnetic disk storage device 102. The input / output request 133 from the upper application processing means 112 to the magnetic disk storage device 102 includes the device number of the magnetic disk storage device 102. In this embodiment, when the operation control means 110 has the request 133 without the disk cache control means 130 and the memory device 120, the operation control means 110 causes the operation control means 110 to search the device control means search table 113 and the input / output request 133. The magnetic disk storage device 102 is specified based on the device number included in, and the input / output request is passed to the magnetic disk storage device control means 111. The magnetic disk storage device control means 111 sends the input / output request 139.
Based on the above, an input / output request 140 is made to the magnetic disk storage device 102, and read / write input / output 137 and 138 are made through the input / output bus 101.

As shown in FIG. 1, in a computer system 100 including a disk cache control means 120, a memory device control means 131, and a disk cache in which a memory device 120 is added to an operation control means 110, a memory device is provided. 120 is a volatile memory 121 having a backup battery 122,
It has a backup battery charge state confirmation means 123 for detecting the charge state of the backup battery 122 from the operation control means 110, and a DMA controller 124 for performing DMA transfer between a main storage device (not shown) and the volatile memory 121. The memory device 120 can directly input / output 136 from the application processing unit 112 to the volatile memory 121 through the memory device control unit 131.

Next, the operation control means 110, the memory device control means 131 for controlling the input and output of data to and from the memory device 120, and the device control means search table 113.
The part corresponding to the device number of the magnetic disk storage device 102 is stored in the magnetic disk storage device control means 111, and the part is rewritten to the device number of the memory device 120. By the rewriting, the input / output request 133 from the application processing unit 112 to the magnetic disk storage device 102 and the input / output request 13 to the magnetic disk storage device 102 by the disk cache control unit 130.
Input / output request 13 to the memory device 120
Then, the volatile memory 121 is cached.

The application processing means 112 makes a write input / output request 13 to the magnetic disk storage device 102.
When performing 3, the disk cache control means 130
The data of the request 133 is not directly written into the magnetic disk storage device 102 through the magnetic disk storage device control means 111, but is written into the volatile memory 121 through the memory device control means 131. The disk cache control unit 130 transfers the data of the volatile memory 121 from the volatile memory 121 to the main memory by DMA data transfer asynchronously with the operation of the application processing unit 112, and through the magnetic disk storage device control unit 111. Write to the magnetic disk storage device 102. The application processing means 112 is the magnetic disk storage device 10.
When making a read I / O request 133 to the disk 2, the disk cache control unit 130 determines whether the requested data exists in the volatile memory 121 by referring to a cache management table (not shown). If the data exists, the data of the volatile memory 121 is read into the main storage device through the memory device control means 131 and passed to the application processing means 112. If the requested data does not exist in the volatile memory 121, the disk cache control means 130 reads the data of the magnetic disk storage device 102 into the main storage device through the magnetic disk storage device control means 111 and transfers it to the application processing means 112.

When the power supply is cut off due to the normal operation stop of the electronic computer 103, all unwritten data in the magnetic disk storage device 102 of the volatile memory 121 is transferred to the main storage device by the DMA controller 124 through the memory device control means 131. Read and write to the magnetic disk storage device 102 through the magnetic disk storage device control means 111.

At the start of operation of the electronic computer 103, the disk cache control means 130 investigates the charge state of the volatile memory backup battery 122 by the volatile memory backup battery charge state confirmation means 123 and examines the volatile memory backup battery 122. When the battery 122 is still in a state in which power can be supplied, the volatile memory 121
It is confirmed whether or not there is unwritten data in the magnetic disk storage device 102. If there is unwritten data, the data is read into the main storage device by the DMA controller 124, and the magnetic disk storage device control program 111 Through the magnetic disk storage device 102. When there is a write input / output request from the application processing unit 112 to the magnetic disk storage device 102,
The disk cache control means 130 writes the data in the volatile memory 121.

Next, the device control means search table 113
An input / output request 133, 134, 139, 140, a magnetic disk storage device control means 130, a memory device control means 131, a disk cache control means 130,
This embodiment will be described with reference to FIG. 2 and FIG. First, the functional configuration shown in FIG. 2 has a memory device control means 131 and a disk cache control 13 which are components for operating the disk cache of the present invention.
In the state where 0 is not added, that is, in the normal state of the computer 103 that does not have the disk cache, the device control means search table 220, the input / output request to the magnetic disk storage device 102, and the magnetic disk storage device control means 111 It shows the relationship. The input / output request structure 200 is created by the application processing means 112 or the operation control means 210 each time a write / read request from the application processing means 112 to various storage devices is made, and is erased when the input / output is completed. The input / output request structure 200 has a device number 20.
1, the start position of the storage device, the amount of data, the flag bit indicating the difference between input and output, and the control information 202 necessary for the input / output request. The device number 201 is a numerical value that is pre-assigned to all storage devices and input / output devices on a one-to-one basis and that can identify the device.

The device control means search table 220 is a one-dimensional array storing the calling address of the device control means for controlling the corresponding device by using the device number as an index.
The read address of the magnetic disk storage device control means 111 is stored in the location of the array corresponding to the device number of the magnetic disk storage device 102. When an input / output request is issued from the application processing unit 112 to the magnetic disk storage device 102, the operation control unit 210 refers to the device number 201 in the input / output request structure 200, and the device control unit search table corresponding to the device number 201. 220
The location of the array is obtained and the device control means is called. Since the device number of the magnetic disk storage device 102 is set in the device number 201, the calling address of the magnetic disk storage device control means 111 for controlling the magnetic disk storage device 102 is obtained from the device control means search table 220. The operation control means 210 can call the control means 111. The called magnetic disk storage device control means 111 performs input / output to / from the magnetic disk storage device 102 according to the input / output information 202. In the object-oriented operation control means 110, when an upper-level control means such as an application processing means calls a lower-level control means to use a certain function, details are different, but the indirect call as described above is generally used. Take the way.

In FIG. 3, the memory device control means 31 and the disk cache control means 130 are added to the functional configuration of FIG. 2, the device control means search table 113 and the input / output request 1 are added.
33, 134, 139, 140, the magnetic disk storage device control means 111, the memory device control means 131, and the disk cache control means 130 are shown.
The disk cache control unit 130 detects the amount of data in the disk cache or the operating load state of the magnetic disk storage device 102, generates a trigger for writing back to the disk cache, and controls the device corresponding to the device number of the disk storage device 102. The location of the array of the means search table 113, that is, the calling address of the magnetic disk storage device control means 111 is referred to, and the address is stored in the calling address storage area 132 of the magnetic disk storage device control means 111. The location of the array of the device control means search table 113 corresponding to the device number of the magnetic disk storage device 102 is rewritten to the calling address of the disk cache control means 130. Since the memory device 120 is an input / output device, it has a device number, and the call address of the memory device control means 13 is stored by the operation control means 110 at the location of the arrangement of the device control means search cable 113 corresponding to the device number. .

In the above state, when the application processing means 112 issues an input / output request to the magnetic disk storage device 102, the operation control means 110.
Refers to the device number 201 in the input / output request structure 200, obtains the location of the array of the device control means search table 113 corresponding to the device number 201, and calls the device control means. The device number 201 is the magnetic disk storage device 102.
Although the device number of the disk cache control means 1 is set, the disk cache control means 1 is set in the location corresponding to the device number of the magnetic disk storage device 102 in the device control means search table 113
Since the call address of 30 is stored, the call address of the disk cache control means 130 is acquired, and the control means 1 is obtained from the operation control means 110.
30 is called. The called disk cache control means 130 analyzes the input / output information 202 and creates the input / output request structure 300 for calling the lower device control means. When it is necessary to make an input / output request to the memory device 120 in the process of cache processing, the operation control means 110 is accessed through the device control means search table 113.
When the memory device controller 131 needs to call the memory device controller 131 and to make an input / output request to the magnetic disk memory device 102, the calling address memory area 132 of the magnetic disk memory device controller 111 is referred to and the magnetic disk memory device controller 111 is referred to. Call.

Next, management of read or write data will be described.

Volatile memory 121 in memory device 120
Referring to FIG. 4 showing the storage area divided into blocks, the volatile memory 121 is divided into a management area 410 and a data area 420. Next, the data area 420 is divided into cache blocks 421 to 42n, which are cache data management units. The write data to the magnetic disk storage device 102 is divided into cache blocks, and the cache blocks 421 to 42n are divided.
Written to, receive data transfer under cache control. A management unit lock 4 for storing management information corresponding to the cache blocks 421 to 42n in the management area 410
It is divided into 11 to 41n. That is, the management unit lock 411
Stores the management information of the cache block 421, and the management block 41n stores the management information of the cache block 42n. In each management block 41n, a flag bit 41n-10 indicating a cache block state, a device number of the magnetic disk storage device, a start position of a storage area of the magnetic disk storage device, a valid data length, etc. are written to the magnetic disk storage device 102. And the cache information 41n-20 necessary for the storage.

In the flag bit 41n-10, there is write data to the magnetic disk storage device 102 in the corresponding cache block, and the magnetic disk storage device 1
Dirty bit 41 indicating that data has not been written to 02
n-11 is provided. When the write request to the magnetic disk storage device 102 is accepted, the disk cache control unit 111 writes the requested data to the cache block (empty cache block) 42N in which valid data is not written by the memory device control unit 131. After the memory device 120 itself has finished writing, after writing the management information of the data to the management block 41n without passing through the memory device control means 131, the flag bit 41
The dirty bit 41n-11 of n-10 is turned on to notify the upper control means of the completion of writing.

Further, the disk cache control means 130
Then, LRU (least recently used)
Dirty bit 41n-11 is turned on using
The management blocks 411 to 41n, which are set to, are managed and are detected when the number of free cache blocks falls below a certain number or when the operating load of the magnetic disk storage device 102 is low, and written to the cache block 42n. The unwritten data in the magnetic disk storage device 102 is written in the magnetic disk storage device 102. The disk cache control means 130 writes the write data to the magnetic disk storage device 102 on the cache block 42n without passing through the memory device control means 131.
24, the data is read into the main storage device, the data is referred to the cache information 41n-20, and the magnetic disk storage device 102 is passed through the magnetic disk storage device control means 111.
Write to, and the dirty bit 41n-11 of the flag bit 41n-10 is turned off. When the power supply is cut off due to a normal operation stop of the electronic computer 103, the dirty bit 41n-1 is prepared in preparation for a long-time operation stop (power supply cutoff state).
The unwritten data of the cache block in which 1 is ON is written to the magnetic disk storage device 102 in the same manner as described above.

When the computer system 100 is turned on and the operation is started, the disk cache control means 130
First, the volatile memory backup battery charge state confirmation means 123 of the memory device 120 first checks the state of charge of the backup battery 122, and the backup battery 122 can supply power to the volatile memory 121. Flag data 4 of the management blocks 411 to 41n if the data of
Inspect all 1n-10, dirty bit 41n-11
The unwritten data in the magnetic disk storage device 102 of the cache block 42n whose ON is ON is read into the main storage device by the DMA controller 124, the cache information 41n-20 of the data is referred to, and the magnetic disk storage device control means After writing to the magnetic disk storage device 102 through 111, finally, the flag bit 41
Turn off the dirty bit 41n-11 of n-10. When the data content of the volatile memory 121 cannot be guaranteed, the disk cache control means 130
Informs the administrator of the electronic computer system 100 that the data in the magnetic disk storage device 102 needs to be restored by means of displaying a message to that effect on the system console terminal.

[0026]

As described above, according to the present invention, the hardware configuration and operation control means of the operating computer system are not replaced, and the conventional hardware / software resources are used to make the cost relatively low. In addition, the disk cache can be added to the computer system without degrading the data integrity of the magnetic disk storage device.

[Brief description of drawings]

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

FIG. 2 is a diagram illustrating a relationship between a device control unit search table, an input / output request, and a magnetic disk storage device control unit.

FIG. 3 is a diagram illustrating the relationship among a device control means search table and an input / output request, a magnetic disk storage device control means, a memory device control means, and a disk cachet control means.

FIG. 4A is a diagram illustrating an area division of a volatile memory in a memory device, and FIG. 4B is a diagram illustrating a management unit block.

[Explanation of symbols]

100 electronic computer system 101 input / output bus 102 magnetic disk storage device 103 electronic computer 110 operation control means 111 magnetic disk storage device control means 112 application processing means 113 device control means search table 120 memory device 121 volatile memory 122 for volatile memory backup Battery 123 Volatile backup battery charge state confirmation means 130 Disk cache control means 131 Memory device control means

Claims (2)

[Claims] 1. An input / output bus connecting an input / output device including a storage device, and a magnetic disk storage device as a secondary storage connected to the bus, and controlling input / output of the magnetic disk storage device. Included in the input / output request of the magnetic disk storage device control means, the device control means for controlling the device identified by the device number assigned to each of the input / output devices connected to the input / output bus, and the application processing means. Operated by an object-oriented operation control means including a device control means search table for associating a device number with a device control means, and means for searching the device control means search table by the device number and activating the corresponding device control means. In the electronic computer system, the cache storage for the secondary storage magnetic disk storage device is performed. A volatile memory, a battery that backs up the power of the volatile memory when the power is cut off, a means for detecting the state of charge of the battery, and a data transfer between the main storage device as primary storage and the volatile memory. DMA
A memory device including data transfer means and connected to the input / output bus, a memory device control means added to the operation control means for controlling input / output to / from the memory device, and a magnetic disk from the application processing means. In response to an input / output request to a storage device, the memory device is operated as cache storage of the magnetic disk storage device, and data is transferred from the cache storage to the magnetic disk storage device via the main storage device. An electronic computer system, comprising: a disk cache comprising: a disk cache control means added to the operation control means for controlling the generation of a data transfer trigger. 2. The data transfer start timing generated by the disk cache control means is when the data in the disk cache reaches a predetermined amount or when the operating load of the magnetic disk storage device falls below a predetermined value.
The electronic computer system according to claim 1, wherein: