Anybody else seen this one?

	sys__sysctl ->
	kern_sysctl ->
	sysctl_procargs ->
	uvm_io -> # creates kernel mapping
	uiomove ->
	kcopy ->
	bcopy ->
	trap ->
	uvm_fault ->  # acquires shared lock for kernel map
	pmap_enter ->
	pmap_enter_pv ->
	pmap_alloc_pv ->  # but pv_nfree is 0, so.....
	uvm_km_zalloc (== uvm_km_alloc1) ->
	uvm_map ->
	uvm_map_lock ->
	lockmgr(kernel_map, LK_EXCLUSIVE # hangs forever waiting for above
shared lock to go away

	Note that the WEHOLDIT test under LK_EXCLUSIVE doesn't help because
it is
	impossible to identify the owner[s] of shared locks.

Got any good ideas? I understand that the kernel is based on current as of
7/17.

thanks,
Duncan