How to optimize and tune the kernel parameters of a Linux system to improve performance

How to optimize and adjust the kernel parameters of a Linux system to improve performance

Abstract: The Linux operating system is one of the most popular operating systems in the world, with powerful performance and flexible configuration options. This article describes how to improve performance by optimizing and adjusting the kernel parameters of your Linux system. Starting from understanding the meaning of kernel parameters, we will explore common performance tuning techniques, including memory management, disk IO, network and scheduler. Through these optimizations and adjustments, users can better utilize the Linux system and improve work efficiency and system response speed.

1. Introduction

The Linux kernel is the core of the operating system and controls all aspects of the system. By optimizing and adjusting kernel parameters, the performance and stability of the system can be improved. This article will introduce some common kernel parameters and provide some optimization tips so that readers can adjust them according to their own needs.

2. Understanding the kernel parameters

Before starting to optimize and adjust, you first need to understand the meaning and function of the kernel parameters. Kernel parameters are options configured by the kernel through files in /sys, /proc and other file systems. The behavior of the kernel can be changed by modifying the values ​​in these files. For most users, the most important kernel parameters are those passed to the kernel via the bootloader when booting the system.

3. Memory Management

Memory is an important indicator of system performance. Optimizing memory management can improve the operating efficiency of the system. Memory management can be optimized using the following parameters:

• vm.swappiness: Controls how often the kernel swaps data from memory to swap space. Setting its value to a lower value (such as 10) can reduce swapping and improve system performance.
• vm.vfs_cache_pressure: Set the ratio of file system cache to dentry and inode cache. Increasing its value (such as 1000) can reduce the use of file system cache and improve system performance.

4. Disk IO

Disk IO is another key factor in system performance. Disk IO can be optimized using the following parameters:

• elevator: Select the disk I/O scheduler. Common schedulers include CFQ, NOOP and Deadline. Choosing the appropriate scheduler based on the specific situation can improve disk IO performance.
• vm.dirty_ratio and vm.dirty_background_ratio: Control how much memory the kernel reserves before starting to write back dirty pages (pages that have been modified but have not been written back to disk). Increasing its value can improve write performance but may increase memory pressure.

5. Network

The network is an important part of modern computer systems. The following parameters can be used to optimize network performance:

• net.core.somaxconn: Sets the maximum number of connections per listening socket in the system. Its value can be increased to improve handling of concurrent connections.
• net.ipv4.tcp_tw_reuse and net.ipv4.tcp_tw_recycle: Allow the operating system to reuse sockets in TIME_WAIT state. This is very useful for highly concurrent network applications.

6. Scheduler

The scheduler is the core component that determines how processes allocate CPU time. By optimizing scheduler parameters, the response speed of the system can be improved. The following parameters can be used to optimize the scheduler:

• kernel.sched_min_granularity_ns and kernel.sched_wakeup_granularity_ns: adjust the granularity of scheduling. Appropriate adjustment of these parameters can improve the response speed of the system.
• kernel.sched_migration_cost_ns and kernel.sched_nr_migrate: Adjust the cost and frequency of process migration. The performance of multi-core systems can be improved by appropriately adjusting these parameters.

7. Conclusion

By optimizing and adjusting the kernel parameters of the Linux system, users can improve the performance and stability of the system. This article introduces some common kernel parameters and optimization techniques so that readers can adjust them according to their own needs. However, it is important to note that you need to be cautious when making parameter adjustments, and test and evaluate the effects of adjustments based on specific circumstances.

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