[seiji]

The most thorough treatment is Bovet & Cesati (944 pages): http://www.amazon.com/Understanding-Linux-Kernel-Third-Editi...

A good "gentle introduction" book is the Love book (440 pages): http://www.amazon.com/Linux-Kernel-Development-Robert-Love/d...

[pwaring → seiji]

Isn't Bovet & Cesati a bit out of date now? I used to have a copy, but it was published in 2005, which means it was probably written in 2004.

Also, it's not kernel-specific, but this book covers a lot of system programming concepts (expensive though):

http://www.amazon.co.uk/Linux-Programming-Interface-System-H...