The Symptom
You are likely here because you tried to boot your computer and one or more kernel drivers failed to load, resulting in one or more of your pieces of hardware failing to work. If you examined your system logs carefully, you may even find some of the following messages appearing amongst all the other chatter that happens during the booting phase:
allocation failed: out of vmalloc space - use vmalloc=<size> to increase size.
You may also see one or more of the following messages:
cx18-1: ioremap failed, perhaps increasing __VMALLOC_RESERVE in page.h
Firstly, do not change things in page.h as suggested--there is a far easier way to fix this once you understand the problem. Fixing this is actually relatively simple, but it's important that you understand what causes it so that you can remedy it correctly.