LOR in VM (with backtrace)

CURRENT dated June 19;

lock order reversal
 1st 0xc45788ac vm object (vm object) _at_ /a/asami/portbuild/i386/src-client/sys/vm/vm_object.c:1506
 2nd 0xc082f110 system map (system map) _at_ /a/asami/portbuild/i386/src-client/sys/vm/vm_kern.c:328

Debugger(c03f450d,c082f110,c043190e,c043190e,c043178f) at Debugger+0x54
witness_lock(c082f110,8,c043178f,148,d8ca79f8) at witness_lock+0x6ac
_mtx_lock_flags(c082f110,0,c043178f,148,c4496850) at _mtx_lock_flags+0xb1
_vm_map_lock(c082f0b0,c043178f,148,c025dc34,246) at _vm_map_lock+0x36
kmem_malloc(c082f0b0,1000,101,d8ca7a8c,c0390425) at kmem_malloc+0x65
page_alloc(c083a240,1000,d8ca7a7f,101,c0457e2c) at page_alloc+0x27
slab_zalloc(c083a240,101,c04332aa,66e,c414e5c4) at slab_zalloc+0x155
uma_zone_slab(c083a240,101,c04332aa,66e,0) at uma_zone_slab+0xd8
uma_zalloc_internal(c083a240,0,101,6ee,0) at uma_zalloc_internal+0x55
uma_zfree_arg(c414e5a0,d7a86000,0,1,0) at uma_zfree_arg+0x2cc
swp_pager_meta_free(c45788ac,1d,0,1,0) at swp_pager_meta_free+0x1b2
swap_pager_freespace(c45788ac,1d,0,1,0) at swap_pager_freespace+0x57
vm_object_backing_scan(c4bec5c8,4,c0432299,5f7,c0432299) at vm_object_backing_scan+0x28a
vm_object_collapse(c4bec5c8,0,c0432299,1ef,c45a0ec4) at vm_object_collapse+0x11a
vm_object_deallocate(c4fab940,c5093ce4,c4fab940,c5093ce4,d8ca7c60) at vm_object_deallocate+0x28e
vm_map_entry_delete(c1506100,c5093ce4,c043197c,86d,c041ada4) at vm_map_entry_delete+0x3b
vm_map_delete(c1506100,0,bfc00000,c1506100,c4123f00) at vm_map_delete+0x413
vm_map_remove(c1506100,0,bfc00000,11d,65) at vm_map_remove+0x55
exit1(c4496850,0,c041a26b,65,d8ca7d40) at exit1+0x63d
sys_exit(c4496850,d8ca7d10,c0437c26,3fd,1) at sys_exit+0x41
syscall(2f,2f,2f,0,ffffffff) at syscall+0x26e
Xint0x80_syscall() at Xint0x80_syscall+0x1d
--- syscall (1, FreeBSD ELF32, sys_exit), eip = 0x2829e9ff, esp = 0xbfbfde3c, ebp = 0xbfbfde58 ---

[...]
#10 0xc037fef6 in _vm_map_lock (map=0x0, file=0x0, line=0)
    at /a/asami/portbuild/i386/src-client/sys/vm/vm_map.c:388
#11 0xc037efe5 in kmem_malloc (map=0xc082f0b0, size=4096, flags=257)
    at /a/asami/portbuild/i386/src-client/sys/vm/vm_kern.c:328
#12 0xc03906a7 in page_alloc (zone=0xc083a240, bytes=0, pflag=0x0, wait=0)
    at /a/asami/portbuild/i386/src-client/sys/vm/uma_core.c:802
#13 0xc0390425 in slab_zalloc (zone=0xc083a240, wait=257)
    at /a/asami/portbuild/i386/src-client/sys/vm/uma_core.c:711
#14 0xc03915d8 in uma_zone_slab (zone=0xc083a240, flags=257)
    at /a/asami/portbuild/i386/src-client/sys/vm/uma_core.c:1493
#15 0xc0391865 in uma_zalloc_internal (zone=0xc083a240, udata=0x0, flags=257)
    at /a/asami/portbuild/i386/src-client/sys/vm/uma_core.c:1648
#16 0xc0391bdc in uma_zfree_arg (zone=0x101, item=0xd7a86000, udata=0x0)
    at /a/asami/portbuild/i386/src-client/sys/vm/uma_core.c:1786
#17 0xc037a292 in swp_pager_meta_free (object=0xc45788ac, index=15621429236810645533, count=1)
    at uma.h:257
#18 0xc0378367 in swap_pager_freespace (object=0xc45788ac, start=15621429236810645533, size=1)
    at /a/asami/portbuild/i386/src-client/sys/vm/swap_pager.c:551
#19 0xc0388b3a in vm_object_backing_scan (object=0xc4bec5c8, op=4)
    at /a/asami/portbuild/i386/src-client/sys/vm/vm_object.c:1395
#20 0xc038795a in vm_object_collapse (object=0xc4bec5c8)
    at /a/asami/portbuild/i386/src-client/sys/vm/vm_object.c:1543
#21 0xc03862de in vm_object_deallocate (object=0xc4bec5c8)
    at /a/asami/portbuild/i386/src-client/sys/vm/vm_object.c:502
#22 0xc038255b in vm_map_entry_delete (map=0xc1506100, entry=0xc5093ce4)
    at /a/asami/portbuild/i386/src-client/sys/vm/vm_map.c:2034
#23 0xc0382993 in vm_map_delete (map=0xc1506100, start=3305716964, end=3217031168)
    at /a/asami/portbuild/i386/src-client/sys/vm/vm_map.c:2166
#24 0xc0382a15 in vm_map_remove (map=0xc1506100, start=0, end=3217031168)
    at /a/asami/portbuild/i386/src-client/sys/vm/vm_map.c:2188
#25 0xc0240f2d in exit1 (td=0xc4496850, rv=0) at vm_map.h:191
#26 0xc02408e1 in sys_exit () at /a/asami/portbuild/i386/src-client/sys/kern/kern_exit.c:102
#27 0xc03d2a8e in syscall (frame=
      {tf_fs = 47, tf_es = 47, tf_ds = 47, tf_edi = 0, tf_esi = -1, tf_ebp = -1077944744, tf_isp = -657818252, tf_ebx = 674341884, tf_edx = 10, tf_ecx = 674341520, tf_eax = 1, tf_trapno = 12, tf_err = 2, tf_eip = 673835519, tf_cs = 31, tf_eflags = 642, tf_esp = -1077944772, tf_ss = 47})
    at /a/asami/portbuild/i386/src-client/sys/i386/i386/trap.c:1023
#28 0xc03c2eed in Xint0x80_syscall () at {standard input}:138
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