assertion tr_owner == curthread in setrunnable

[Matthew Dillon]

:This bug is still present.
:
:I got a crash this morning with a 2.7.3.1084.g7b033-DEVELOPMENT kernel.
:The machine had a 3 day uptime and was doing a buildworld.
:
:Core files can be downloaded from http://dl.zefyris.com/
:
:-- 
:Francois Tigeot

    Very nice crash dump.  I think I found the case that can cause the
    situation, it is a very rare but nasty bug which can cause the proc_token
    to be unexpectedly released.

    I have made a commit to address the issue (b528f10fca...).  Hopefully
    this will crush the bug.

					-Matt
					Matthew Dillon 
					<dillon at backplane.com>