How to install src of kernel with yum

[Bruno Wolff III]

On Sun, Dec 05, 2010 at 10:19:27 +0800,
  Yunchi Wang <wyunchilovechina at gmail.com> wrote:
> Thank you.But i still don't understand what system do when compiling a
> module.How can he know where the source of kernel is?Just put the source
> under /usr/src/kernel then name it as current kernel?Or config the
> environment variables?

If you are building add on modules you typically don't need the source.
You want kernel-headers and kernel-devel or kernel-PAE-devel installed.