Lock order reversal

Dear colleagues,

===
lock order reversal
 1st 0xc2f4b128 vm object (vm object) _at_ vm/vm_object.c:432
 2nd 0xc082f110 system map (system map) _at_ vm/vm_kern.c:325
Stack backtrace:
backtrace(c04eacec,c082f110,c04fb2fa,c04fb2fa,c04fb1a2) at backtrace+0x17
witness_lock(c082f110,8,c04fb1a2,145,c082f0b0) at witness_lock+0x692
_mtx_lock_flags(c082f110,0,c04fb199,145,101) at _mtx_lock_flags+0xb1
_vm_map_lock(c082f0b0,c04fb199,145,0,c05b4600) at _vm_map_lock+0x36
kmem_malloc(c082f0b0,1000,101,d258fac4,c044c7df) at kmem_malloc+0x3a
page_alloc(c083a1c0,1000,d258fab7,101,c05ae0e0) at page_alloc+0x27
slab_zalloc(c083a1c0,101,8,c04fcb37,664) at slab_zalloc+0x14f
uma_zone_slab(c083a1c0,101,c04fcb2e,664,0) at uma_zone_slab+0xcb
uma_zalloc_internal(c083a1c0,0,101,6e8,0) at uma_zalloc_internal+0x55
uma_zfree_arg(c268aa80,d1c77e04,0,1,0) at uma_zfree_arg+0x2bf
swp_pager_meta_free_all(c2f4b128,c04faaf9,c04faa91,1b2) at swp_pager_meta_free_all+0x18f
swap_pager_dealloc(c2f4b128,1,c04fca3d,10c,0) at swap_pager_dealloc+0x113
vm_pager_deallocate(c2f4b128,0,c04fbc2b,25f,1b0) at vm_pager_deallocate+0x3d
vm_object_terminate(c2f4b128,0,c04fbc2b,1b0,d258fc14) at vm_object_terminate+0x1e8
vm_object_deallocate(c2f4b128,c2b9bd20,c2f4b128,c2b9bd20,d258fc68) at vm_object_deallocate+0x35f
vm_map_entry_delete(c2ab2a00,c2b9bd20,c04fb368,8bc,0) at vm_map_entry_delete+000,0,bfc00000,c2ab2a00,c26fc700) at vm_map_delete+0x3d3
vm_map_remove(c2ab2a00,0,bfc00000,11d,65) at vm_map_remove+0x55
exit1(c2aa15f0,0,c04e5b6a,65,d258fd40) at exit1+0x60d
sys_exit(c2aa15f0,d258fd14,c0500c6f,3fd,1) at sys_exit+0x41
syscall(2f,2f,2f,0,ffffffff) at syscall+0x251
Xint0x80_syscall() at Xint0x80_syscall+0x1d
--- syscall (1), eip = 0x280d159f, esp = 0xbfbff42c, ebp = 0xbfbff448 ---
===

    5.1-CURRENT from July, 6, 2003. GENERIC kernel.
---
    Yours
        Andrew Kolchoogin.                              [DREW-RIPE, AKOL-RIPN]

... Contrary to popular belief, UNIX is user-friendly. It just happens to be
    very selective about who it decides to make friends with.     A. Haiut.