LOR: vm_object.c and vm_kern.c

I got following LOR message today. Vm_object.c was rev 1.287.

lock order reversal
 1st 0xc203c688 vm object (vm object) _at_ /usr/freebsd/src/sys/vm/vm_object.c:512
 2nd 0xc082f110 system map (system map) _at_ /usr/freebsd/src/sys/vm/vm_kern.c:325
Stack backtrace:
backtrace(c038cad0,c082f110,c039c77a,c039c77a,c039c609) at backtrace+0x17
witness_lock(c082f110,8,c039c609,145,0) at witness_lock+0x697
_mtx_lock_flags(c082f110,0,c039c609,145,3) at _mtx_lock_flags+0xb1
_vm_map_lock(c082f0b0,c039c609,145,ccea6a18,c01f4be4) at _vm_map_lock+0x36
kmem_malloc(c082f0b0,1000,101,ccea6a84,c030b500) at kmem_malloc+0x66
page_alloc(c083a240,1000,ccea6a77,101,c03c570c) at page_alloc+0x27
slab_zalloc(c083a240,101,c039e03e,66f,c18684a4) at slab_zalloc+0x150
uma_zone_slab(c083a240,101,c039e03e,66f,0) at uma_zone_slab+0xd8
uma_zalloc_internal(c083a240,0,101,6ef,0) at uma_zalloc_internal+0x55
uma_zfree_arg(c1868480,cc9a69b4,0,1,0) at uma_zfree_arg+0x2cb
swp_pager_meta_free_all(c203c688,c039bfee,c039bf7a,1af) at swp_pager_meta_free_a
ll+0x1b0
swap_pager_dealloc(c203c688,1,c039df29,10b,0) at swap_pager_dealloc+0x113
vm_pager_deallocate(c203c688,0,c039d0cf,25e,c03fb888) at vm_pager_deallocate+0x3
d
vm_object_terminate(c203c688,0,c039d0cf,200,c22e30f0) at vm_object_terminate+0x1
f4
vm_object_deallocate(c203c688,c22e30f0,c203c688,c22e30f0,ccea6c24) at vm_object_
deallocate+0x217
vm_map_entry_delete(c1c66000,c22e30f0,c039c7e8,86e,0) at vm_map_entry_delete+0x3
b
vm_map_delete(c1c66000,0,bfc00000,c1c66000,c1847c00) at vm_map_delete+0x453
vm_map_remove(c1c66000,0,bfc00000,111,c0389ff3) at vm_map_remove+0x58
exit1(c1c3be40,f,c0389ff3,8bb,81) at exit1+0x626
sigexit(c1c3be40,f,c0389ff3,844,0) at sigexit+0x1a7
postsig(f,0,c038c55c,f7,20800) at postsig+0x11b
ast(ccea6d48) at ast+0x448
doreti_ast() at doreti_ast+0x17