[OFFTOPIC] Opinions on the O'Reilly book: http://www.oreilly.com/catalog/linuxkernel/

[Walter Tautz <wtautz@math.uwaterloo.ca>]

Has anyone read it and do you have an opinion on the least
painful way to learn about the kernel...reading the source
is presumably the only way if one really wants to get into
the heart of the matter? 

-walter