From: Jarek Poplawski <redacted>
Date: Wed, 23 Jul 2008 06:20:36 +0000

PS: if there is nothing new in lockdep the classical method would
be to change this static array:

static struct lock_class_key
netdev_xmit_lock_key[ARRAY_SIZE(netdev_lock_type)];

to

static struct lock_class_key
netdev_xmit_lock_key[ARRAY_SIZE(netdev_lock_type)][MAX_NUM_TX_QUEUES];

and set lockdep classes per queue as well. (If we are sure we don't
need lockdep subclasses anywhere this could be optimized by using
one lock_class_key per 8 queues and spin_lock_nested()).

Unfortunately MAX_NUM_TX_QUEUES is USHORT_MAX, so this isn't really
a feasible approach.

spin_lock_nested() isn't all that viable either, as the subclass
limit is something like 8.