Which Part Of The Linux Kernel Is Responsible For Memory Management?

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The process of managing your computer's memory resources, including allocating, releasing, and managing memory for active applications, the operating system, and other system processes, is called memory management in Linux.

Thanks to the virtual memory model used to map a program's memory addresses to physical memory locations, multiple applications can run simultaneously on Linux without interfering with each other. In Linux, the kernel is responsible for managing memory allocation and deallocation. This also ensures that each task has access to the memory it needs to run.

Therefore, the entire process in Linux is called memory management. Later in this article you will learn more about the process and how memory management works in Linux.

Here are some of the key memory management concepts in Linux.

Introduction to virtual memory

Virtual memory is a technology that allows a computer to use more memory than it physically has, using disk space as an extension of physical memory. In Linux, virtual memory is implemented via the paging mechanism. Paging divides memory into smaller blocks, called pages, which can be allocated or freed as needed.

When an application requires more memory than it available physical memory, Linux uses the kernel as an extension of physical memory, called swap space. This Linux memory management technique also helps to avoid memory-related crashes and improve system stability.

Next, you need to know the concept of pages of memory, known as a crucial segment of the Linux operating system

Concept of memory pages

Memory pages are the basic unit of memory allocation and management in the Linux operating system. In most modern hardware architectures, a page is a contiguous block of memory of a fixed size, typically 4 KB. The Linux kernel divides the system's accessible physical memory into pages, each with its own physical address.

These pages are then mapped to virtual addresses so that each process has your physical address. it has its own direction. Address range corresponding to physical memory. The kernel's virtual memory manager is responsible for this allocation. In the context of Linux memory management, memory pages are an essential component that enables efficient allocation and management of memory resources for individual processes running on the system.

So that was a short definition of memory pages. Now we will understand the types of memory pages and start with large pages.

Large pages

Large pages in Linux are large memory pages that can significantly improve system performance by reducing memory management overhead. They are typically 2 MB or 1 GB in size and can be allocated dynamically by the kernel or manually by system administrators.

Huge file management pages Linux memory is particularly useful for large workgroup applications, such as databases and scientific computing, because they reduce the number of page table entries needed to handle a given amount of memory, which results in faster data access, reduced CPU usage and improved overall system performance. .

Zone

In Linux, a zone is a logical grouping of memory pages with similar properties . such as access permissions or physical location. Each area is managed separately by the kernel and can be used for a specific purpose, such as allocating memory for user processes or for the kernel itself. There are several types of zones in Linux, including user zone, kernel zone, and I/O zone. area. Each zone has its own memory management policies and can be divided into smaller zones for more granular control.

Page cache

Page caching in Linux is a mechanism for caching data from disk to memory to speed up access times. When data is read from a hard drive, it is stored in the page cache for quick access when needed. It can significantly improve system performance and reduce disk reads required.

In Linux Storage Management, a node refers to a set of physical or logical storage identified by a unique address on the system. The kernel can manage each node separately and assign them to specific purposes, such as user processes or the kernel itself.

In simple terms, nodes are a form of partitioning system. memory in discrete blocks. Each node has its own memory and is responsible for managing its own memory allocations. And nodes are useful in multiprocessor systems where processors can access memory on their own node faster than on another node.

Anonymous memory

In Linux, anonymous memory refers to a type of memory used from The Kernel runtime is dynamically assigned and is not associated with a specific file or device. It is used by processes to store data that does not need to be stored permanently on disk, such as: B. program stacks and dynamic memory. The use of anonymous memory in Linux memory management allows processes to actively allocate and free memory without needing to know the physical location.

OOM Killer

The Out-Of-Memory (OOM) Killer is a feature of the Linux kernel responsible for reclaiming memory from processes that have exhausted the system's memory resources. If a system runs out of available memory, it may experience performance issues or even become unresponsive. MOO Killer's goal is to prevent this from happening by automatically terminating processes that consume a disproportionate amount of memory.

Compression

In Linux memory management, compression is a kernel mechanism used to defragment a system's memory. Move memory pages to create larger contiguous blocks of free memory. Helps reduce memory fragmentation and improve overall system performance.

Recover

This refers to the Linux term "grievance". refers to the process of freeing memory that is no longer actively used by a process or application. When a process or application allocates memory, it reserves a portion of the system's memory for use. The Linux kernel provides several garbage collection mechanisms, including page garbage collection, plate garbage collection, and in-place garbage collection. CMA debug< div>

CMA debug interface

Debug CMA (Contiguous Memory Allocator) The Linux interface allows you to view and modify CMA settings and configurations. It allows developers and administrators to monitor CMA usage, view allocation statistics, and change allocation policies. The Debugfs interface provides a convenient way to troubleshoot and optimize the use of CMA on systems that require contiguous memory allocation, such as: B. Video processing, graphics playback, and other multimedia applications.

How to check memory usage in Linux?

In Linux, you can use various commands to check memory usage memory. The most commonly used command is free, which displays the total amount of free and used physical memory and swap space in the system. Another useful command is top, which displays real-time information about memory usage while the process is running.

Check memory usage with the ps command

The ps command can also display memory usage information for processes specific. Other commands such as vmstat and sar provide more detailed information about system memory usage over time. Knowing how to check memory usage in Linux is important for system administrators and users because it allows you to monitor system performance and diagnose memory-related problems.

Let's learn more. in the two most commonly used commands in Linux memory management to check memory usage.

Check memory usage in the 'free' command guide

The "free" command displays the total amount of free and used physical memory and swap space on the system, as well as the buffers and cache used by the kernel. By default, output is displayed in kilobytes, but can be changed using the -m or -g options to display information in megabytes or gigabytes, respectively.

The free version The command is a useful tool for monitoring system performance and diagnosing memory-related problems because it provides real-time information about system memory usage.

Conclusion

Managing memory and disk usage is an important aspect of system administration in Linux.
Proper memory management ensures that your system has enough memory to run applications. and prevents the system from running out of memory.

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Answered 11 months ago Evelyn HarperEvelyn Harper