net: gen_estimator: Fix gen_kill_estimator() lookups
net: gen_estimator: Fix gen_kill_estimator() lookups

gen_kill_estimator() linear lists lookups are very slow, and e.g. while
deleting a large number of HTB classes soft lockups were reported. Here
is another try to fix this problem: this time internally, with rbtree,
so similarly to Jamal's hashing idea IIRC. (Looking for next hits could
be still optimized, but it's really fast as it is.)

Reported-by: Badalian Vyacheslav <c5269813e77759c32f9f4bfaf7771b1bffeeb04a@bigtelecom.ru>
Reported-by: Denys Fedoryshchenko <d29de71aea38aad3a87d486929cb0aad173ae612@visp.net.lb>
Signed-off-by: Jarek Poplawski <85e4e0cd35fdfcbe234be29b330d591ff9717625@gmail.com>
Acked-by: Jamal Hadi Salim <f626bfe8a6716f0e60b0f3989b67f5ad2fa9fda2@cyberus.ca>
Signed-off-by: David S. Miller <fe08d3c717adf2ae63592e4c9aec6e3e404d8e3e@davemloft.net>

KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs,KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas,TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs,KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas