When should I write a Linux kernel module?

Question

Some people want to move code from user space to kernel space in Linux for some reason. A lot of times the reason seems to be that the code should have particularly high priorit

Answer 1

I'm not sure the question is the right way around. There should be a good reason to move things to kernel space. If there aren't any reasons, don't do it.

For one thing, debugging is made harder, and the effect of bugs is far worse (crash/panic instead of simple coredump).