Transitioning if_addr_lock to an rwlock

[Gleb Smirnoff]

On Thu, Dec 22, 2011 at 11:30:01AM -0500, John Baldwin wrote:
J> You can find the patch for 8.x at 
J> http://www.freebsd.org/~jhb/patches/if_addr_rwlock.patch

Just my two pennies: for head/ patching if ip_carp.c should
be straightforward:

1) Using W in carp_alloc_if() and carp_free_if().
2) Using R everywhere else.

-- 
Totus tuus, Glebius.