The Linux kernel is the core part of all GNU/Linux operating systems. The kernel is designed to run on a large variety of hardware, from web servers to routers and embedded devices. The default versions of the Linux kernel that arrive with the mainstream Linux distros are optimized for some very basic use cases. For instance, Ubuntu comes in Server, Desktop, IoT, and Cloud editions – each with basic optimizations tailored for the usage scenario.

Most distros make some effort to customize the kernel for its intended purpose; however, no one but you knows exactly how you are using your own system. You can tweak the Linux kernel in hundreds of different ways to improve performance or reduce latency. I'll outline some of those techniques in this article. Of course, some of these tweaks might have already been enabled by your distro's vendor; others are more specific and are seldom used at all. The goal of this discussion is to take you down inside the kernel and to demonstrate various performance-related optimizations. Needless to say, tricks with the kernel have the potential to destabilize your system. These ideas are best explored with a test system – at least at first, until you are sure everything is working.

I'll discuss a range of Linux kernel optimizations with the goal of improving perceived desktop performance, including smoothness and snappiness. Such things may have little effect in synthetic tests (such as the ones often conducted by Phoronix), but they can have a strong effect on the user. I am aiming this discussion at desktop and laptop users, including the significant number of people who need to run Linux on low-performance and legacy hardware.

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