Just noticed this new bug report in my bug DB:
http://grabjohn.com/kernelbugdatabase/index.php?action=21&id=59
Kernel compilation with devfs chosen in config fails. The compiler complains that "p_opptr" is not a member of struct task_struct. This is because the names of this family have changed in sched.h. Changing the references in base.c from "p_opptr" to "parent" solves the problem.
John.