Empty linux/config.h

Hi,

I am trying to compile a very simple ( hello world ) module that I saw
in www.faqs.org/docs/kernel/x145.html, but I got some errors related
with CONFIG_HZ not being defined.
After a little research I concluded it should be defined in
linux/config.h.
My suse 10.0 linux/config.h is empty, so what is the point in having an
empty config.h ?
Is that the place where CONFIG_HZ should be defined ?

Thanks in advance for your attention,

.