[RFC][CFT] GEOM direct dispatch and fine-grained CAM locking

Hi. I would like to invite more people to review and test my patches for improving CAM and GEOM scalability, that for last six months you could see developing in project/camlock SVN branch. Full diff of that branch against present head (r255131) can be found here:

kgdb 'next' command crashes kernel during inter-VM kernel debugging

I am trying to debug kernel in one VBox VM from another VBox VM using this howto: http://census-labs.com/news/2009/01/19/freebsd-kernel-debugging with the exception that on the target VM hint.uart.0.flags=0x90 is set instead. It works, stops at breakpoints, etc. However, kgdb command n (next)