JP2022019083A - Information processing device and information processing system for managing storage destination for files stored in nonvolatile memory - Google Patents

Abstract

To efficiently distribute files and extend the life of a nonvolatile memory subject to limitation on the number of times writes are performed.SOLUTION: A history of writes to files is recorded in a file information storage unit 12 while a regular task execution unit 11 executes regular tasks, and when a file storage destination change request unit 14 outputs a request, a file storage destination determination unit 15 determines a file storage destination on the basis of the history of writes stored in the file information storage unit 12 such that the frequency of writes to a second nonvolatile memory 125 is lowered. A file storage destination change unit 16 causes the files to be stored at the storage destination (first nonvolatile memory 124 or second nonvolatile memory 125) determined by the file storage destination determination unit 15.SELECTED DRAWING: Figure 2

Description

The present invention relates to an information processing apparatus and an information processing system that manages a storage destination of a file stored in a non-volatile memory.

A control device for controlling an industrial machine such as a machine tool is provided with a storage device for storing a control program for controlling the industrial machine and recording the operating status of the industrial machine. The control device is often installed in an environment in which a plurality of industrial machines operate, and operates in a poor condition that is easily affected by vibration or the like. Therefore, in the control device, a semiconductor storage using a NAND flash, which has no driving portion and is not easily affected by vibration, may be used as a storage device.

In a non-volatile memory using a NAND flash such as SSD (Solid State Drive), data is written and read in a unit called a page which is a set of memory cells. In addition, the data written on the page is erased in the unit of a block in which a plurality of pages are put together. Since the data cannot be overwritten in the flash memory, when the data in the page is changed, the data of the entire block including the page is temporarily saved, the block is erased, and then the changed data is used. And write back the entire block.

A memory cell of a flash memory using a NAND flash is deteriorated by electrons penetrating an oxide film which is an insulator in principle of operation, so that the number of writes is limited. Therefore, in the flash memory, the write / erase count for each block is counted, and the write control (wear leveling) is performed so that the write / erase count for each block is as uniform as possible. Therefore, the life of the flash memory can be managed by acquiring the write / erase count of the block having the largest write / erase count from the flash memory. For example, by outputting an alarm when the write / erase count of the block having the largest write / erase count exceeds 90% of the maximum allowable write / erase count, the flash memory having reached the end of its life can be replaced.

On the other hand, the non-volatile memory includes a non-volatile memory that does not have a configuration that is electrically deteriorated, unlike a flash memory. In the present disclosure, such a non-volatile memory is referred to as a non-volatile memory having no limit on the number of writes. Non-volatile memory with no write limit includes, for example, MRAM and battery-backed SRAM.
Non-volatile memory with no write limit generally has a high cost per capacity. Therefore, in order to reduce the hardware cost of the non-volatile memory, the conventional device is equipped with both a non-volatile memory having a write count limit and a non-volatile memory having no write count limit, and the non-volatile memory has a write count limit. Some memory stores files with low write frequency, and some non-volatile memory with no limit on the number of writes stores files with high write frequency.

However, the write frequency is not known in advance, and there are files whose write frequency changes according to the usage status of the control device, the usage status of the machine to be controlled, and the usage status of the function of each machine. It is not possible to know which data is written frequently before using the controller.

As a technique for saving a file with a high write frequency in a non-volatile memory with no limit on the number of writes, if the amount of writes (or the frequency of writes or the number of writes) from a certain task to the flash memory is higher than a certain threshold, the task There is a technique for saving a file from to in a non-volatile memory with no limit on the number of writes. See, for example, Patent Document 1.

Japanese Patent Publication No. 6193834

Since the non-volatile memory having no limit on the number of writes has a high cost per capacity, it is common to estimate the usage amount before the start of use and to install the non-volatile memory having the minimum required capacity. Therefore, if more writes are performed than expected, it is necessary to replace the memory with a non-volatile memory having a large capacity.

Replacing the non-volatile memory is costly and laborious. In order to make effective use of hardware resources, it is better to be able to continue using the non-volatile memory that was originally installed without replacing it.

When using both non-volatile memory with no write limit and non-volatile memory with write limit, files are efficiently distributed so that the originally installed non-volatile memory can be used without replacement. However, a technique for extending the life of a non-volatile memory having a limited number of writes is desired.

One aspect of the present disclosure is an information processing apparatus, which is a first non-volatile memory having no write count limit, a second non-volatile memory having a write count limit, and a normal task execution unit for executing a normal task. And the file information storage unit that stores the file write history in a normal task, and the file stored in the file information storage unit so that the write frequency of the second non-volatile memory is low based on the file write history. A file save destination determination unit that determines a save destination, and a file save destination change unit that saves a file in the first non-volatile memory or the second non-volatile memory according to the save destination determined by the file save destination determination unit. Have.

One aspect of the present disclosure is an information processing system, in which a first non-volatile memory having no write count limit, a second non-volatile memory having a write count limit, and a normal task execution unit for executing a normal task. And the file information storage unit that stores the file write history in a normal task, and the file stored in the file information storage unit so that the write frequency of the second non-volatile memory is low based on the file write history. It has a file storage destination determination unit that determines a storage destination, and a file storage destination change unit that stores a file in a first non-volatile memory or a second non-volatile memory according to the storage destination determined by the file storage destination determination unit. ..

According to the present disclosure, when both a non-volatile memory with no write limit and a non-volatile memory with a write limit are used, the files are efficiently distributed and the life of the non-volatile memory with a write limit is extended. Can be extended.

It is a hardware block diagram of the information processing apparatus of this disclosure. It is a block diagram of the information processing apparatus of 1st disclosure. It is a figure which shows an example of a file information storage part. It is a figure which shows an example of the write history to a non-volatile memory. It is a figure which shows an example of the combination of files, the total used capacity of the 1st non-volatile memory, and the total write frequency of a 2nd non-volatile memory. It is a block diagram of the information processing apparatus of the second disclosure. It is a figure which shows an example of the file storage part at the time of performing a write frequency correction. It is a block diagram of the information processing apparatus provided with the relocation execution part. It is a flowchart explaining the relocation process. It is a block diagram of the information processing apparatus which provided the file information storage part in the 1st non-volatile memory. It is a block diagram of the information processing apparatus which provided the file information storage part in the 2nd non-volatile memory. It is a block diagram of the information processing apparatus which provided the file information storage part in the 3rd non-volatile memory.

[First disclosure]
Hereinafter, an example of the information processing apparatus 1 of the present disclosure will be shown. The information processing device 1 can be implemented as a control device for controlling an industrial machine such as a machine tool. The present disclosure is applied to the information processing apparatus 1 that uses both the non-volatile memory having no write count limit and the non-volatile memory having a write count limit, and the type of the information processing apparatus 1 is not particularly limited.

As shown in FIG. 1, the information processing apparatus 1 includes a CPU 111 that controls the information processing apparatus 1 as a whole, a ROM 112 that records programs and data, and a RAM 113 that temporarily expands the data, and the CPU 111 is a bus 120. The system program recorded in the ROM 112 is read out via the system program, and the entire information processing apparatus 1 is controlled according to the system program.

The interface 115 is an interface 115 for connecting the information processing device 1 and an external device 121 such as an adapter. Programs, various parameters, etc. are read from the external device 121 side. Further, the program edited in the information processing apparatus 1, various parameters, and the like may be stored in the external storage means via the external device 121.

The information processing device 1 is connected to the display unit 122 via the interface 116. The information processing device 1 manages files, which will be described later. The program for file management is stored in the first non-volatile memory 124, the second non-volatile memory 125, and the third non-volatile memory 127, which will be described later.

The non-volatile memory includes a first non-volatile memory 124 having no write count limit and a second non-volatile memory 125 having a write count limit. The first driver 118 accepts a file read request and a file write request from the CPU 111, and controls reading and writing of data to the first non-volatile memory 124. The second driver 119 accepts a file read request and a file write request from the CPU 111, and controls reading and writing of data to the second non-volatile memory 125.
The first non-volatile memory 124 is an MRAM or a battery-backed SRAM. MRAM is a kind of semiconductor memory, which uses a magnetic material as a part of the material of a storage element and records a signal by changing the magnetization. The recorded information does not disappear even if the power is lost. SRAM is a kind of volatile semiconductor memory, but it can be used as a non-volatile memory in which the contents are not lost even if the power of the main body of the device is turned off by combining a small battery. The first non-volatile memory 124 is suitable for use in factories and the like because it is resistant to shock and vibration because it does not have a drive unit, but the cost per capacity is high, so that the usable capacity is limited.
The second non-volatile memory 125 is, for example, a flash memory. A flash memory is one of storage devices using a semiconductor element, and can be repeatedly written many times, and the stored contents are maintained even when the energization is stopped. Flash memory is suitable for use in factories because it is resistant to shocks and vibrations because it does not have a drive unit, but the number of writes is limited due to the structure of the element.

The first non-volatile memory 124 and the second non-volatile memory 125 are user-operated and information processing devices input via a program or an input unit read from an external device 121 via interfaces 115, 116 and 117. Various data (for example, setting parameters, sensor information, etc.) acquired from each part of 1 or industrial machinery are stored.

[First disclosure]
FIG. 2 is a block diagram of the information processing apparatus 1 of the present disclosure. The information processing device 1 includes a normal task execution unit 11 that executes a normal task that the information processing device should originally perform, a file information storage unit 12 that stores a file write history in the normal task, and a file storage destination (first non-volatile). A file management unit 13 that manages the sex memory 124 or the second non-volatile memory 125) is provided.

The normal task execution unit 11 executes the entire task excluding the file management of the present disclosure. Such a task is called a normal task. The normal task is not a special task but a general task necessary for the information processing apparatus 1 to operate. For example, when the information processing device 1 is a numerical control device, the information processing device 1 analyzes a machining program, generates a command to a machine tool, and outputs the generated command. Also, when an error occurs, a warning is issued or the machine is stopped. Accepts input from the user and accepts various setting changes. The normal task means the entire task executed when the information processing apparatus 1 is activated.

The file information storage unit 12 stores the file writing history and the file storage destination in the normal task execution unit 11. The file information storage unit 12 of FIG. 3 stores a file name, a file write frequency, a file size, and storage destination information. The write frequency is the number of writes per day in each file. The write frequency is calculated by dividing the total number of file writes by the number of days. The file size is the file size of each file. In the save destination information, it is recorded whether the save destination of each file is the first non-volatile memory 124 or the second non-volatile memory 125. The default save destination is recorded in the save destination information until the file management unit 13 determines the save destination of the file. The default save destination is, for example, a save destination expected before the start of use of the information processing apparatus 1, but is not limited to this.

The file management unit 13 determines whether to save the file in the file storage destination change request unit 14 instructing the start of file management, the first non-volatile memory 124, or the second non-volatile memory 125. It has a predetermined unit 15 and a file storage destination changing unit 16 for storing a file in the determined storage destination.

The file save destination change request unit 14 starts the file save destination change processing. The file save destination change request unit 14 can set the start timing of the file save destination change processing. The start timing may be, for example, when a preset energization time has elapsed, a time set by the user, or when the write frequency of the second non-volatile memory 125 exceeds a certain threshold value. The start timing condition may be set in advance or may be set by default.
Further, as an application, the write frequency of the file and the operating state of the information processing device 1 are stored in association with each other, and when the operating state of the information processing device 1 changes, a save destination change request is output and the operating state is output. You may decide where to save the file based on the write frequency associated with.

When the file save destination determination unit 15 receives the save destination change request, the file save destination determination unit 15 saves each file so that the write frequency of the second non-volatile memory 125 is low based on the write history recorded in the file information storage unit 12. To determine.

The file save destination changing unit 16 outputs a command to the first driver 118 and the second driver 119, and saves the file in the determined save destination (first non-volatile memory 124 or second non-volatile memory 125). Let me.

[How to determine the file save destination]
An example of how to determine the save destination of a file is shown. In this example, for all combinations of storage destinations of each file, the total used capacity of the first non-volatile memory 124 and the second used capacity of the first non-volatile memory 124 in each combination are referred to with reference to the write history of the files stored in the file information storage unit 12. The total write frequency of the non-volatile memory 125 is calculated.
As a result, the combination in which the total used capacity of the first non-volatile memory 124 does not exceed the upper limit of the capacity of the first non-volatile memory 124 and the total write frequency of the second non-volatile memory 125 is the lowest is adopted. ..

For example, in FIG. 4, looking at the write history, four files 1 to 4 are written, and the file capacities of each file 1 to 4 are 300 Kbyte, 500 Kbyte, 800 Kbyte, and 200 Kbyte, respectively, and each file. The daily writing frequency of 1 to 4 is 4 times, 5 times, 10 times, and 3 times.

The combinations of the four files, the total usage of the first non-volatile memory 124 for each combination, and the total write frequency of the second non-volatile 125 memory are as shown in FIG.
For each combination, the total of the file capacities allocated to the first non-volatile memory 124 (hereinafter referred to as the total used capacity of the first non-volatile memory 124) is the maximum capacity of the first non-volatile memory 124 (1024Kbyte). The combinations that are less than are combinations 1 to 5 and combinations 9 to 13.
Among the combinations in which the total used capacity of the first non-volatile memory 124 does not exceed the maximum capacity of the first non-volatile memory 124, the combination having the lowest total write frequency of the second non-volatile memory 125 is the combination 13. be. Based on this result, the file storage destination determination unit 15 determines that the storage destination of the file 1 and the file 2 is the second non-volatile memory 125, and the storage destination of the file 3 and the file 4 is the first non-volatile memory 124.

The method of determining the save destination of the file is not limited to the above method. For example, when the file information storage unit 12 is referred to and the files with the highest number of writes are allocated to the first non-volatile memory 124 in order, and the total capacity of the allocated files exceeds the maximum capacity of the first non-volatile memory 124. May decide to allocate subsequent files to the second non-volatile memory 125.
The file storage destination determination unit 15 determines the storage destination of each file so that the write frequency of the second non-volatile memory 125 is low based on the write history of the file stored in the file information storage unit 12.

[Second disclosure]
FIG. 6 is a block diagram of the information processing apparatus 1 of the second disclosure. In the second disclosure, the information processing apparatus 1 includes a write frequency correction unit 17.
The write frequency correction unit 17 excludes data whose write frequency temporarily fluctuates greatly in the write history. For example, the frequency of writing files is temporarily increased during machine adjustment. The write frequency correction unit 17 performs, for example, a quartile or an outlier test, and when the write frequency is high or low, the data at that time is excluded from the write history.

FIG. 7 is an example of the file information storage unit 12 when the writing frequency is corrected. When correcting the write frequency, record the write frequency for each file at predetermined time intervals. In FIG. 7A, the writing frequency for each day time is recorded, such as the first day, the second day, and so on.
As shown in FIG. 7B, if the writing frequency of a file on the first day is 9 times, the second day is 11 times, the third day is 100 times, and the fourth day is 10 times, only the third day Is fluctuating greatly. The writing frequency correction unit 17 excludes the data on the third day and calculates the average of the first day, the second day, and the fourth day. Since the average value is 10 [times / day], this value is the corrected write frequency.

The file save destination is calculated based on the write frequency after modification. By modifying the write frequency, it is possible to manage a file that functions efficiently in a steady use state without being affected by a temporary change, for example, the number of writes is 100 on the third day.

[Relocate files]
When the save destination of the file is decided, it is necessary to relocate the file to move the file to the decided save destination. The information processing device 1 of FIG. 8 includes a rearrangement execution unit 18. The relocation execution unit 18 relocates the files as follows.
First, the file is moved from the first non-volatile memory 124 to the second non-volatile memory 125 according to the storage destination information of the file information storage unit 12. The file is first moved from the first non-volatile memory 124 to the second non-volatile memory 125 because the capacity of the second non-volatile memory 125 is large and there is free space in the memory.
Next, the file recorded in the second non-volatile memory 125 is moved to the first non-volatile memory 124 according to the storage destination information of the file information storage unit 12. When all the files recorded in the file information storage unit 12 are moved, the rearrangement of the files is completed.

The information processing device 1 may be stopped due to a power failure, an error, or the like. The relocation execution unit 18 stores information about the relocated file in order to continuously restart the relocation process even if the relocation process is interrupted.
In the present disclosure, it is assumed that the files stored in the file information storage unit 12 are assigned the file numbers File 1, File 2, File 3, .... The rearranged file information storage unit 19 stores the number N of the moved file each time the file is moved. The last file number of the file information storage unit 12 is called the maximum file number.

The rearrangement process will be described with reference to FIG.
The relocation execution unit 18 first sets the file number N to 1 (step S1). This indicates that the file 1 is the target of the relocation process. Next, referring to the file information storage unit 12, if the file N is a file to be moved from the first non-volatile memory 124 to the second non-volatile memory 125, the first non-volatile memory 124 to the second non-volatile memory 124 is used. The file N is moved to the memory 125 (step S2). When the relocation process of the file N is completed, the file number is incremented by 1 (step S3).

The relocation execution unit 18 compares the file number N incremented in step S3 with the maximum file number of the file information storage unit 12, and if the file number N is equal to or less than the maximum file number (step S4; No), step S2. And relocates the file N.
When the file number N exceeds the maximum file number (step S4; Yes), the movement of the file from the first non-volatile memory 124 to the second non-volatile memory 125 is completed. The relocation execution unit 18 shifts the process to step S5.

The relocation execution unit 18 sets the file number N to 1 (step S5). This indicates that the file 1 is the target of the relocation process. Next, referring to the file information storage unit 12, if the file N is a file to be moved from the second non-volatile memory 125 to the first non-volatile memory 124, the second non-volatile memory 125 to the first non-volatile memory 124 is used. The file N is moved to the memory 124 (step S6). When the relocation process of the file N is completed, the file number is incremented by 1 (step S7).

The relocation execution unit 18 compares the file number N incremented in step S3 with the maximum file number of the file information storage unit 12, and if the file number N is equal to or less than the maximum file number (step S8; No), step S6. And relocate the file N.
When the file number N exceeds the maximum file number (step S8; Yes), the movement of the file from the second non-volatile memory 125 to the first non-volatile memory 124 is completed.
Finally, the relocation execution unit 18 assigns 0 to the file number N of the relocation file information storage unit 19 and ends the relocation process (step S9).

The relocation execution unit 18 relocates the file from the first non-volatile memory 124 to the second non-volatile memory 125 in steps S1 to S4, and the second non-volatile memory 125 in steps S5 to S8. To relocate the file to the first non-volatile memory 124.
When the relocation process is interrupted, a file number N other than 0 is stored in the relocation file information storage unit 19.
If the value of the file number N of the relocated file information storage unit 19 is the file number of the file to be saved in the second non-volatile memory 125, it is determined that the file is interrupted immediately after step S2 of the file number N, and the file is filed. Resume from step S2 of the file with the number N + 1.
If the value of the file number N of the relocated file information storage unit 19 is the file number of the file to be stored in the first non-volatile memory 124, it is determined that the file is interrupted immediately after step S6 of the file number N, and the file is filed. Resume from step S6 of the file with the number N + 1.

[Save in file information storage]
The file information storage unit 12 stores in any one of the first non-volatile memory 124, the second non-volatile memory 125, and the third non-volatile memory 127.
FIG. 10 is an example in which the file information storage unit 12 is provided in the first non-volatile memory 124. When the file information storage unit 12 is provided in the first non-volatile memory 124, there is an effect that writing to the file information storage unit does not affect the life of the second non-volatile memory.

FIG. 11 is an example in which the file information storage unit 12 is provided in the second non-volatile memory 125. When the file information storage unit 12 is provided in the second non-volatile memory 125, there is an effect that the capacity of the file information storage unit does not affect the used capacity of the first non-volatile memory, which has a high cost per capacity.

FIG. 13 is an example in which the file information storage unit 12 is provided in the third non-volatile memory 127. When the file information storage unit 12 is provided in the third non-volatile memory 127, writing to the file information storage unit does not affect the life of the second non-volatile memory, and the capacity of the file information storage unit is further increased. There is an effect that the used capacity of the first non-volatile memory, which has a high cost per capacity, is not affected.

As described above, the information processing apparatus 1 according to the present disclosure has at least two non-volatile memories 124, that is, a first non-volatile memory 124 having no write count limit and a second non-volatile memory 125 having a write count limit. , 125, while the normal task execution unit 11 is executing a normal task, a file write history is created in the file information storage unit 12, and a second non-volatile memory 125 is created based on the file write history. Decide where to save each file so that it is written less frequently.

Further, based on the write history of the file, the save destination of the file is determined so as to store as many files as possible in the first non-volatile memory 124 having no limit on the number of writes.

By excluding data whose write frequency fluctuates greatly, it is possible to manage files that function efficiently in steady use without being affected by temporary changes.

In addition to determining the save destination of the file, the file is rearranged to the determined save destination. When relocating, the moved file number is stored. Therefore, even if the processing is interrupted, it can be continuously restarted.

1 Information processing device 11 Normal task execution unit 12 File information storage unit 13 File management unit 14 File storage destination change request unit 15 File storage destination determination unit 16 File storage destination change unit 17 Write frequency correction unit 18 Relocation execution unit 19 Relocation File information storage unit 111 CPU
118 1st driver 119 2nd driver 122 Display unit 123 Input unit 124 1st non-volatile memory 125 2nd non-volatile memory 126 3rd driver 127 3rd non-volatile memory

Claims (12)

The first non-volatile memory with no write limit and
A second non-volatile memory with a write limit and
A normal task execution unit that executes normal tasks, and a normal task execution unit
A file information storage unit that stores the file write history in the normal task,
A file storage destination determination unit that determines a storage destination of a file stored in the file information storage unit so that the write frequency of the second non-volatile memory is low based on the file write history.
A file storage destination change unit for storing a file in the first non-volatile memory or the second non-volatile memory according to a storage destination determined by the file storage destination determination unit.
Information processing device with. The information processing apparatus according to claim 1, wherein the writing history of the file includes at least the writing frequency and the file size of each file. Based on the write history of the file, the file storage destination determination unit does not exceed the upper limit of the file capacity of the first non-volatile memory and reduces the write frequency of the second non-volatile memory. The information processing apparatus according to claim 1, wherein the storage destination of each file is determined. Based on the write history of the file, the file storage destination determination unit is a file that does not exceed the upper limit of the file capacity of the first non-volatile memory and the write frequency of the second non-volatile memory is low. The information processing apparatus according to claim 1, wherein the combination of storage destinations is determined. The information processing apparatus according to claim 1, further comprising a file save destination change request unit that requests the start of changing the save destination of the file according to a predetermined condition set in advance. The information processing apparatus according to claim 1, further comprising a write frequency correction unit that excludes a temporarily changing write frequency from the write frequency of the second non-volatile memory. The first aspect of claim 1 having a relocation execution unit that relocates a file stored in the first non-volatile memory or the second non-volatile memory based on a file storage destination determined by the file storage destination determination unit. Information processing equipment. It is equipped with a relocation file information storage unit that stores the identification information of the file for which relocation is being executed.
The information processing apparatus according to claim 7, wherein the rearrangement execution unit restarts the rearrangement based on the identification information. The information processing apparatus according to claim 1, wherein the file information storage unit is provided in the first non-volatile memory. The information processing apparatus according to claim 1, wherein the file information storage unit is provided in the second non-volatile memory. The information processing apparatus according to claim 1, wherein the file information storage unit is provided in the first non-volatile memory and a third non-volatile memory different from the second non-volatile memory. The first non-volatile memory with no write limit and
A second non-volatile memory with a write limit and
A normal task execution unit that executes normal tasks, and a normal task execution unit
A file information storage unit that stores the file write history in the normal task,
A file storage destination determination unit that determines a storage destination of a file stored in the file information storage unit so that the write frequency of the second non-volatile memory is low based on the file write history.
A file storage destination change unit that stores a file in the first non-volatile memory or the second non-volatile memory according to a storage destination determined by the file storage destination determination unit.
Information processing system with.

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