Optimization of the Linux Kernel

Linux Kernel can be optimized in the following way

Remove Unnecessary Functionality

[Decision on "What is essential?" and "What is extra?" depends upon the actual product definition]

• Drivers and subsystems that are not required in the product can simply be left out of the kernel configuration.
• If the product does not support any of MTD devices, the corresponding drivers and support for flash file systems like JFFS2 can be removed from the kernel configuration.

Postpone (Deferred Initialization)

[?initcalls for some modules may take quite long delaying the boot process]

• Locate the initcall definition of these modules in the source code.
• Change the declaration of the initcalls from?module_init()?to?deferred_module_init()
• Once the system has booted, deferred initcalls can be executed by:

$ echo 1 >/proc/deferred_initcalls.

For Example, in one of our projects we reduced init time from 2+ secs to 0.2+ secs.

Debugging Optimization

[debug infrastructure can be removed.]

???????? Remove option?-g?from the compiler.

???????? Disable?Kernel debugging

???????? Disable?Debug Filesystem

???????? Disable?Tracer

There are other methods also available that can be implemented for optimizing the Linux Kernel, we will discuss further.