Loadable Kernel Module - Fragmentation Penalty

One minor criticism of preferring a modular kernel over a static kernel is the so-called Fragmentation Penalty. The base kernel is always unpacked into real contiguous memory by its setup routines; so, the base kernel code is never fragmented. Once the system is in a state where modules may be inserted—for example, once the filesystems have been mounted that contain the modules—it is probable that any new kernel code insertion will cause the kernel to become fragmented, thereby introducing a minor performance penalty.