rbtree
lib/rbtree.c

outras árvores balanceadas?!?
lib/radix-tree.c
lib/prio_tree.c
lib/btree.c



hash (pid, tcp/ip, etc)

include/linux/hash.h
uXX hash_long(uXX val, bits);

Sistemas de arquivos e net hashs.
include/net/inet_hashtables.h
fs/*/*hash*
net/ipv4/fib_hash.c