company-mode question.

[Maindoor]

Hi,
Can you someone tell me how to use company-mode on GNU Emacs
for the linux kernel ?

I can't find the instructions anywhere on the net and the general
documentation doesn't help.
For example I created etags for the kernel and then opened up a
C file and started writing a function that should highlight the
fields in task_struct. But there is no popup. What am I doing wrong ?
But the example as shown in the demo works. The page can be found
here: http://nschum.de/src/emacs/company-mode/

Thanks,
Maindoor