[PATCH] Lockmgr deadlock on STABLE_8

[Pete French]

> Also enable INVARIANTS.

Including INVARIANTS stops my kernel from building. It
has been this way since 8.0 (this is why I only
had WITNESS compiled in). It fails with many many
errors like this:

/usr/src/sys/vm/vm_map.c:575: undefined reference to `_mtx_assert'

My kernel config file looks like this:

	include         GENERIC
	ident           WITNESS

	options         KDB
	options         DDB
	options         WITNESS
	options         INVARIANTS


> While there (with my patch applied) please setup textdump in order to
> report the following DDB commands (and once it deadlocks break in
> DDB):
> bt, show allpcpu, ps, alltrace, show alllocks

Having read the manual page for textdump, I am not sure I
will be able to get a dump out of this machine, as it has no
swap configured (and no spare partition that I can
allocate for such a thing). I have tried using dumpon
to dump to a ZVOL, but it gives me an error saying
that it is not supported. Is there anything I can do
to remedy this ?

> Try also to get a coredump (and if you can't report immediately to us
> and try to not turn off the machine in order to apply following
> instructions).

That's fine - this machine is more or less dedicated as a
test ,machine for 8.0 right now. I can possibly dive you console
access to it fi required in fact, as I did this for Robert
once to sort out a problem with 7.0

I'll try running with the current KDB and DDB kernel until
I can figure out how to get a WITNESS/INVARIANTS one built,
and will let you know when that deadlocks.

cheers,

-pete.