lockorder reversal on vm_object.c vm_kern.c (with backtrace)

Got this error today when I dropped out of X/KDE.  First time I've seen it
pop up when dropping out of X/KDE.  Machne got real sluggish when I did exit
out and took a couple of minutes for console to re-appear and the first
thing that jumped across when console did come back up was the following:


lock order reversal
 1st 0xc8a18534 vm object (vm object) _at_ /usr/src/sys/vm/vm_object.c:512
 2nd 0xc082f110 system map (system map) _at_ /usr/src/sys/vm/vm_kern.c:325
Stack backtrace:
backtrace(c0517ac1,c082f110,c05292c2,c05292c2,c052915d) at backtrace+0x17
witness_lock(c082f110,8,c052915d,145,0) at witness_lock+0x697
_mtx_lock_flags(c082f110,0,c052915d,145,3) at _mtx_lock_flags+0xb1
_vm_map_lock(c082f0b0,c052915d,145,e847ea58,c03334d4) at _vm_map_lock+0x36
kmem_malloc(c082f0b0,1000,101,e847eac4,c0478510) at kmem_malloc+0x66
page_alloc(c083a240,1000,e847eab7,101,c058294c) at page_alloc+0x27
slab_zalloc(c083a240,101,c052ab26,66f,c5c6a4a4) at slab_zalloc+0x150
uma_zone_slab(c083a240,101,c052ab26,66f,0) at uma_zone_slab+0xd8
uma_zalloc_internal(c083a240,0,101,6ef,0) at uma_zalloc_internal+0x55
uma_zfree_arg(c5c6a480,e69739b4,0,1,0) at uma_zfree_arg+0x2cb
swp_pager_meta_free_all(c8a18534,c0528b64,c0528af8,1af) at
swp_pager_meta_free_all+0x1b0
swap_pager_dealloc(c8a18534,1,c052aa29,10b,0) at swap_pager_dealloc+0x113
vm_pager_deallocate(c8a18534,0,c0529bff,25e,c05cd328) at
vm_pager_deallocate+0x3d
vm_object_terminate(c8a18534,0,c0529bff,200,c8a4603c) at
vm_object_terminate+0x1f4
vm_object_deallocate(c8a18534,c8a4603c,c8a18534,c8a4603c,e847ec64) at
vm_object_deallocate+0x20f
vm_map_entry_delete(c60a7600,c8a4603c,c0529330,86e,c0513401) at
vm_map_entry_delete+0x3b
vm_map_delete(c60a7600,0,bfc00000,c60a7600,c5c54e80) at
vm_map_delete+0x453
vm_map_remove(c60a7600,0,bfc00000,111,c0512a23) at vm_map_remove+0x58
exit1(c5fb7260,100,c0512a23,63,e847ed40) at exit1+0x626
sys_exit(c5fb7260,e847ed10,c052ebcf,3fb,1) at sys_exit+0x41
syscall(2f,2f,2f,0,2ae4) at syscall+0x26e
Xint0x80_syscall() at Xint0x80_syscall+0x1d
--- syscall (1), eip = 0x2902b71f, esp = 0xbfbff08c, ebp = 0xbfbff0b8 ---



*shrug*  Figured someone here would know what's going on.

>From uname -a:
5.1-RELEASE #7: Wed Jun 18

Sources are from around Jun 9-18.   Any suggestions are more than welcome.
Thanks!




Regards,
Nick H.
nickh_at_supportteam.net