I was in the same situation some months ago...
The lack of precision of ctags is a pain in a.., and i find cscope much better for all the macros related stuff (and there are a bunch of macros in the linux kernel)..
concerning the usage, that's actually straightforward...you just type cscope -R at the root of your kernel and then you've got nothing to worry about.. (I mean if you just want to explore that's perfect...)
Then, the key bindings are all based on Ctrl-\ (you can remap it if you're allergic to Ctrl), you mainly use s and g....,
Developing for the kernel, I didn't need so much the completion....
Anyway, go for cscope, this is much more convenient, accurate.
