KR20090131142A - Apparatus and method for memory management - Google Patents

Abstract

PURPOSE: A memory management device and a method thereof are provided to realize a memory manager and a file system, which can manage an integrated memory for performing all functions of a storage unit and an RAM. CONSTITUTION: A memory device comprises as follows. If a program demands allocation of a memory area, an allocation size determination module(610) determines allocation size of the memory area, based on feature of the demand. An allocation module(620) assigns a space corresponding to the determined size. A meta data management module(630) manages meta data for the allocated space. Even though power supply is intercepted, the memory device prevents data loss as a storage class RAM.

Description

Memory Management Device and Method {APPARATUS AND METHOD FOR MEMORY MANAGEMENT}

The present invention relates to a memory management apparatus and method, and more particularly, to a memory management apparatus and method using a file system optimized for storage class RAM.

This study was conducted as part of the IT growth engine technology development project of the Ministry of Knowledge Economy and ICT R & D. [2006-S-040-03, Development of Embedded Memory Software Technology based on Flash Memory]

As a result of numerous studies conducted over the past decades to improve the performance of computer systems, the memory of computer systems employs a memory hierarchy. Various types of memory devices included in the hierarchical structure are optimized and used at a minimum cost based on characteristics of each of the memory devices. Computer systems can achieve optimal system performance using various types of memory devices that have been optimized.

Memory devices included in the memory hierarchy of a conventional computer system may be classified into two types according to access units and volatility / non-volatility. The first is a memory, commonly called random access memory (RAM), which is accessible in byte units, has fast access speed, and is volatile. Volatile means that the data stored in the memory is lost when the power supply is cut off.

Examples of memory devices included in RAM include static random access memory (SRAM) that can be used as a cache, or dynamic random access memory (DRAM) that can be used as a main memory. Recently, examples of DRAM include synchronous DRAM (SDRAM) and double data rate SDRAM (DDR SDRAM).

The second is a memory device called storage, which is accessible on a block-by-block basis and is relatively slow and nonvolatile. Non-volatile means that the contents stored in the memory are not lost even if the power supply is cut off. This may be a hard disk drive (HDD) or flash memory. HDD or flash memory may be frequently used as secondary storage.

Recently, Storage Class RAM, which has the characteristics of RAM—accessible by byte, fast access speed—and the characteristics of storage—nonvolatile, has been spotlighted as the next generation memory. Examples of storage class RAM include ferro-electric RAM (FRAM), magneto-resistive RAM (MRAM), and phase-change RAM (PRAM).

Disclosure of Invention The present invention has been made to solve the problems of the prior art as described above, and an object thereof is to provide a file system and a memory manager capable of managing an integrated memory (storage) that performs both RAM and storage functions. .

The present invention aims to provide a permanent computing environment for a user.

An object of the present invention is to provide a file system for managing various kinds of objects without wasting space in the memory device.

It is an object of the present invention to provide a memory manager and file system that eliminates the overhead caused by a memory hierarchy.

An object of the present invention is to shorten the boot time by using the integrated memory.

In order to achieve the above object and solve the problems of the prior art, the memory management apparatus according to an embodiment of the present invention is to allocate the size of the memory area based on the characteristics of the request when a program requests allocation of the memory area; An allocation size determining module for determining, an allocation module for allocating a space corresponding to the determined size among spaces of a memory device to the request, and a metadata management module managing metadata for the space allocated to the request. have.

In addition, the memory management method according to another embodiment of the present invention, the step of receiving a request for allocation of a memory area from a program, determining the allocation size of the memory area based on the characteristics of the request, the space of the memory device The method may include allocating a space corresponding to the determined size to the request, and managing metadata about the space allocated to the request.

According to the present invention, it is possible to implement a file system and a memory manager capable of managing integrated memory (storage) that perform both RAM and storage functions.

The present invention can provide a user with a persistent computing environment.

The present invention can provide a file system for managing various kinds of objects without wasting space in the memory device.

The present invention can provide a memory manager and file system that eliminates the overhead caused by a memory hierarchy.

The present invention can reduce the boot time by using the integrated memory.

Hereinafter, with reference to the accompanying drawings, preferred embodiments of the present invention will be described in detail. However, the present invention is not limited or limited by the embodiments. Like reference numerals in the drawings denote like elements.

1 is a diagram illustrating a memory management method according to an embodiment of the present invention.

Referring to FIG. 1, the memory manager 110 may manage the memory device 120 using a memory management method.

The memory device 120 may be part of a memory hierarchy, but may also form a single hierarchy.

When the program calls the malloc function or the kmalloc function, the memory manager 110 generates a dynamic allocate object 121 in the memory device 120 corresponding to the called malloc function or the kmalloc function. Can be.

When the program calls the create function or the write function, the memory manager 110 may create a file object 122 in the memory device 120 corresponding to the called create or write function.

When the program calls the fork function, the memory manager 110 may create a process object 123 corresponding to the called fork function in the memory device 120.

The memory device 120 may process the dynamic allocation object 121 or the process object 123 processed in the conventional main memory, and process the file object 122 processed in the conventional storage. Can be processed. The memory device 120 may provide a unified computing environment to a user by processing functions of a conventional main memory and storage in a single layer. The memory manager 110 may provide a file system and a memory management method optimized for management of the memory device 120 performing an integrated function.

As an example of the memory device 120, a storage class random access memory (RAM) may be used. Storage class RAM provides random accessibility and can also provide non-volatility. When the memory device 120 is a storage class RAM, data or metadata stored in the memory device 120 are not lost even when the power supply is cut off, so the memory manager 110 may provide a permanent computing environment to the user. Can be.

The memory manager 110 may create objects corresponding to the dynamic allocation request, the process creation request, and the file creation request in the memory device 120, and manage the created objects. The memory management method using the memory manager 110 and the memory device 120 may provide a persistent computing environment in which the state of the computer system is set to either running or idle. Conventional memory management methods may set the state of the computer system to either booting, running, or terminating.

The memory manager 110 may provide a memory management method capable of allocating space of the memory device 120 regardless of a lifetime, an attribute, and / or a block size of the created object. . The memory management method may be designed to allocate an object having characteristics such as a variable attribute and a variable block size.

The memory management method may allocate an object having a size of a minimum allocation unit of an operating system (OS), and allocate an object having a size of a block unit of the file system or more. The memory management method may allocate an object without wasting space of the memory device 120, and may change an attribute between objects without additional overhead.

2 is a diagram illustrating a memory management method according to an embodiment of the present invention.

Referring to FIG. 2, the memory manager 210 manages the memory device 220 by a memory management method.

When the program calls the malloc (N) function, the memory manager 210 may set an N byte memory space corresponding to the malloc (N) function. The memory manager 210 may generate a dynamic allocate object 221 in the memory device 220 using the set N-byte memory space.

The memory manager 210 may return a pointer to the set N-byte memory space.

3 is a diagram illustrating a memory management method according to an embodiment of the present invention.

Referring to FIG. 3, the memory manager 310 manages the memory device 320 by a memory management method.

The memory device 320 may store the dynamic allocation object 321 generated corresponding to the malloc (N) function.

create ("file") is a function that creates a file named "file". When the program calls the create ("file") function, the memory manager 310 may set a memory space corresponding to the create ("file") function. The memory manager 310 may generate metadata corresponding to the set memory space and store the generated metadata by using a part of the space of the memory device 320. The memory manager 310 may create a file object 322 in the memory device 320 using the set memory space. The memory manager 310 may store data corresponding to a file in the generated file object 322.

The memory manager 310 may set a memory space corresponding to the create ("file") function based on the block size of the file system. The block size may be determined based on the minimum allocation unit of the OS. For example, if the minimum allocation unit of the OS is 32 bytes, the block size may be 512 bytes, which is 16 times the minimum allocation unit.

4 is a diagram illustrating a memory management method according to an embodiment of the present invention.

Referring to FIG. 4, the memory manager 410 manages the memory device 420 by a memory management method.

The memory device 420 may store a dynamic allocation object 421 generated in response to a malloc (N) function and a file object 422 generated in response to a create ("file") function.

The fork function is a function that creates a new user process or task. When the program calls the fork function, the memory manager 410 may set a memory space corresponding to the fork function. The memory manager 410 may create a process object 423 in the memory device 420 using the set memory space.

When the user process corresponding to the process object 423 is terminated, the memory manager 410 may mark the process object 423 as free and assign it to the request when there is another request from the program. In such a case, an operation of marking an object allocated to a specific request as free is called release.

When the program calls the free function on the dynamic allocation object 421, the memory manager 410 may release the dynamic allocation object 421. The space corresponding to the released object can be allocated when there is another request from the program.

If the memory device 420 is a storage class RAM, the stored objects may be maintained without being lost even when the power supply is cut off. The memory manager 410 may use the objects stored in the memory device 420 without additional initialization even when the memory device 420 is rebooted. The memory management method can reduce boot time since it does not need to perform an initialization process at boot time.

5 is a diagram illustrating a file system of a memory device 500 in which a memory management method is performed, according to an exemplary embodiment.

Referring to FIG. 5, block 0 510 may store information indicating whether each block of blocks 2 to 7 530 is in an allocated state or released state.

Block 1 520 may store information related to an attribute of an object or data stored by each block of blocks 2 to 7 530.

Each block of blocks 2 to 7 530 may be subjected to allocation of a memory management method. The memory management method may allocate block 2 as a file object named "file".

The memory management method may determine the size of the space of the allocated object based on the characteristics of the allocated object. For example, in the case of a file object, the memory management method may determine the size of the space of the file object based on the block size of the file system. If the object is a dynamic allocation object or a process object, the memory management method may determine the size of the space of the object based on the minimum allocation unit of the OS.

When the user requests to generate data corresponding to the dynamic allocation object to a file, the memory management method may create the file object without additional write operation by changing the attribute of the dynamic allocation object to the file object. When the user requests to generate data corresponding to the file object as the dynamic allocation object, the memory management method may change the attributes of the file object to the dynamic allocation object.

The memory management method may perform mapping between two different objects in order to quickly execute an execution file. The memory management method of the present invention may be performed by a memory manager. In the present specification, such a memory manager will be referred to as a unified storage manager (USM).

In the conventional memory hierarchy and file system, in order to execute an executable file, the contents of the executable file are copied to main memory, and then a page table is constructed so that a task or a process can access the contents stored in memory. To associate a task or process with a memory space.

The USM of the present invention can execute the executable file without the overhead of additional copying operation by directly connecting the contents of the executable file to the address space of the task or process. This allows USMs to implement execution in place (XIP). In addition, since the code required for booting is stored in a specific block of the memory device 500, the execution time of the code required for booting can be shortened.

Conventional memory hierarchies and file systems require copying files from storage to main memory when accessing files from within a task or process. However, the USM can read or write data without any additional overhead.

In the conventional memory hierarchy and file system, an operation of copying data on main memory to storage is required before shutting down the computer system, and copying a part of data of the storage to main memory after booting the computer system. This is necessary. However, USM does not require additional overhead to shut down and boot a computer system. This allows USMs to provide a persistent computing environment.

6 is a diagram illustrating a memory management apparatus 600 according to an embodiment of the present invention.

Referring to FIG. 6, the memory management device 600 may manage the memory device 640. The memory management apparatus 600 includes an allocation size determination module 610, an allocation module 620, and a metadata management module 630.

The allocation size determining module 610 may determine the allocation size of the memory area based on the characteristics of the request when the program requests the allocation of the memory area. The allocation size determination module 610 may determine an allocation size of the memory area based on whether the request is a file generation request, a dynamic allocation request, or a process creation request.

The allocation module 620 may allocate a space corresponding to the determined size of the space of the memory device 640 to the request.

The metadata management module 630 may manage metadata about the space allocated to the request.

The memory device 640 may be accessed in units of bytes and may be a storage class RAM that does not lose data even when a power supply is cut off.

The metadata management module 630 may divide the space on the memory device 640 into a plurality of blocks and generate metadata indicating allocation or release of each of the plurality of blocks.

The metadata management module 630 may divide the space on the memory device 640 into a plurality of blocks, and generate metadata indicating the attribute information for each of the plurality of blocks.

The allocation size determination module 610 may determine the allocation size based on the minimum allocation unit of the OS when the request is a request related to the allocation of the dynamic region. In this case, the allocation module 620 may generate the dynamic allocation object and store the dynamic allocation object by using a part of the space on the memory device 640.

The allocation size determining module 610 may determine the allocation size based on a block unit having a size of an integer multiple of the minimum allocation unit when the request is a request related to generation of a file. In this case, the allocation module 620 may generate a file object and store the file object using a part of the space on the memory device 640. The metadata management module 630 may generate metadata corresponding to a space where the file object is stored. The meta data management module 630 may store the generated meta data in a specific space in the memory device 640.

The allocation size determination module 610 may determine the allocation size based on a minimum allocation unit when the request is a request related to the creation of a process. In this case, the allocation module 620 may generate a process object and store the process object using a part of the space on the memory device 640.

The metadata management module 630 may search for a space corresponding to the request among spaces on the memory device 640 based on the characteristics of the request, and change an attribute of the searched space based on the characteristics of the request. .

7 is an operation flowchart illustrating a memory management method according to an embodiment of the present invention.

Referring to FIG. 7, the memory management method receives a request for allocation of a memory area from a program (S710).

The memory management method determines an allocation size of the memory area based on the characteristics of the request (S720).

The memory management method allocates a space corresponding to the determined size of the space of a memory device to the request (S730).

The memory management method manages metadata about the space allocated to the request (S740). At this time, when the program sequence corresponding to the request is terminated, the memory management method may generate metadata indicating release of space allocated to the request.

The memory management method according to the present invention may be embodied in the form of program instructions that can be executed by various computer means and recorded in a computer readable medium. The computer readable medium may include program instructions, data files, data structures, etc. alone or in combination. Program instructions recorded on the media may be those specially designed and constructed for the purposes of the present invention, or they may be of the kind well-known and available to those having skill in the computer software arts. Examples of computer-readable recording media include magnetic media such as hard disks, floppy disks, and magnetic tape, optical media such as CD-ROMs, DVDs, and magnetic disks, such as floppy disks. Magneto-optical media, and hardware devices specifically configured to store and execute program instructions, such as ROM, RAM, flash memory, and the like. Examples of program instructions include not only machine code generated by a compiler, but also high-level language code that can be executed by a computer using an interpreter or the like. The hardware device described above may be configured to operate as one or more software modules to perform the operations of the present invention, and vice versa.

As described above, although the present invention has been described with reference to limited embodiments and drawings, the present invention is not limited to the above embodiments, and those skilled in the art to which the present invention pertains various modifications and variations from such descriptions. This is possible.

Therefore, the scope of the present invention should not be limited to the described embodiments, but should be determined not only by the claims below but also by the equivalents of the claims.

1 is a diagram illustrating a memory management method according to an embodiment of the present invention.

2 is a diagram illustrating a memory management method according to an embodiment of the present invention.

3 is a diagram illustrating a memory management method according to an embodiment of the present invention.

4 is a diagram illustrating a memory management method according to an embodiment of the present invention.

5 is a diagram illustrating a file system of a memory device 500 in which a memory management method is performed, according to an exemplary embodiment.

6 is a diagram illustrating a memory management apparatus 600 according to an embodiment of the present invention.

7 is an operation flowchart illustrating a memory management method according to an embodiment of the present invention.

<Explanation of symbols for the main parts of the drawings>

110: memory manager

120: memory device

Claims (19)

An allocation size determining module that determines an allocation size of the memory area based on a characteristic of the request when a program requests allocation of a memory area; An allocation mode for allocating a space corresponding to the determined size of space of a memory device to the request; And A metadata management module that manages metadata about the space allocated to the request Memory management device comprising a. The method of claim 1, The memory device is a storage class RAM that is accessible in units of bytes and does not lose data even when a power supply is cut off. The method of claim 1, The metadata management module And generating metadata indicating release of space allocated to the request when the program sequence corresponding to the request ends. The method of claim 1, The metadata management module Dividing a space on the memory device into a plurality of blocks, and generating metadata indicating allocation or release of each of the plurality of blocks. The method of claim 1, The metadata management module And dividing a space on the memory device into a plurality of blocks and generating metadata representing attribute information for each of the plurality of blocks. The method of claim 1, The metadata management module And searching for a space corresponding to the request among the spaces on the memory device based on the characteristics of the request and changing an attribute of the searched space based on the characteristics of the request. The method of claim 1, The allocation size determination module And determine the allocation size based on a minimum allocation unit when the request is a request relating to allocation of a dynamic region. The method of claim 1, The allocation size determination module And when the request is a request related to generation of a file, determining the allocation size based on a block unit having a size of an integer multiple of a minimum allocation unit. The method of claim 1, The allocation size determination module And determine the allocation size based on a minimum allocation unit if the request is a request related to creation of a process. Receiving a request for allocation of a memory area from a program; Determining an allocation size of the memory area based on the characteristics of the request; Allocating a space corresponding to the determined size of space of a memory device to the request; And Managing metadata for the space allocated to the request Memory management method comprising a. The method of claim 10, The memory device is a storage class RAM that is accessible in units of bytes and does not lose data even when a power supply is cut off. The method of claim 10, Managing the metadata is And generating metadata indicating release of space allocated to the request when the program sequence corresponding to the request ends. The method of claim 10, Managing the metadata is Dividing a space on the memory device into a plurality of blocks; And Generating metadata indicating allocation or freeing of each of the plurality of blocks Memory management method comprising a. The method of claim 10, Managing the metadata is Dividing a space on the memory device into a plurality of blocks; And Generating metadata indicating attribute information about each of the plurality of blocks; Memory management method comprising a. The method of claim 10, Managing the metadata is Searching for a space of the space on the memory device corresponding to the request based on a characteristic of the request; And Changing an attribute of the searched space based on a characteristic of the request Memory management method comprising a. The method of claim 10, Determining the allocation size And if the request is a request related to allocation of a dynamic region, determining the allocation size based on a minimum allocation unit. The method of claim 10, Determining the allocation size And determining the allocation size based on a block unit having a size of an integer multiple of a minimum allocation unit when the request is a request related to generation of a file. The method of claim 10, Determining the allocation size And if the request is a request related to the creation of a process, determining the allocation size based on a minimum allocation unit. A computer-readable recording medium in which a program for executing the method of any one of claims 10 to 18 is recorded.

Images