LoR in slab allocator and swapper

Just in case no one has reported this one:

FreeBSD 5.2-CURRENT-20040614-JPSNAP #0: Mon Jun 14 01:59:05 GMT 2004
    root_at_ushi.jp.freebsd.org:/usr/obj/usr/src/sys/GENERIC
WARNING: WITNESS option enabled, expect reduced performance.
Preloaded elf kernel "/boot/kernel/kernel" at 0xc09f7000.
Preloaded elf module "/boot/kernel/acpi.ko" at 0xc09f7244.
Timecounter "i8254" frequency 1193182 Hz quality 0
CPU: Intel(R) Pentium(R) III Mobile CPU      1000MHz (999.15-MHz 686-class CPU)
  Origin = "GenuineIntel"  Id = 0x6b1  Stepping = 1
  Features=0x383f9ff<FPU,VME,DE,PSE,TSC,MSR,PAE,MCE,CX8,SEP,MTRR,PGE,MCA,CMOV,PAT,PSE36,MMX,FXSR,SSE>
real memory  = 402063360 (383 MB)
avail memory = 383733760 (365 MB)
[...]
ad0: 19077MB <IC25N020ATMR04-0> [41344/15/63] at ata0-master UDMA100
Mounting root from ufs:/dev/ad0s2a
lock order reversal
 1st 0xc1a31108 vm object (vm object) _at_ /usr/src/sys/vm/swap_pager.c:1313
 2nd 0xc08c6300 swap_pager swhash (swap_pager swhash) _at_ /usr/src/sys/vm/swap_pager.c:1799
 3rd 0xc103fce4 vm object (vm object) _at_ /usr/src/sys/vm/uma_core.c:923
Stack backtrace:
backtrace(0,1,c0894778,c08959e8,c0824a1c) at backtrace+0x12
witness_checkorder(c103fce4,9,c07e2957,39b) at witness_checkorder+0x53b
_mtx_lock_flags(c103fce4,0,c07e2957,39b,c1982328) at _mtx_lock_flags+0x57
obj_alloc(c19aa000,1000,cffeca2f,101,cffeca3c) at obj_alloc+0x31
slab_zalloc(c19aa000,1,c19aa000,c19aa000,c1982320) at slab_zalloc+0x87
uma_zone_slab(c19aa000,1,c1982328,0,c07e2957,78e) at uma_zone_slab+0xb0
uma_zalloc_internal(c19aa000,0,1,c1982328,0) at uma_zalloc_internal+0x29
uma_zalloc_arg(c19aa000,0,1) at uma_zalloc_arg+0x2a2
swp_pager_meta_build(c1a31108,5,0,2,0) at swp_pager_meta_build+0x108
swap_pager_putpages(c1a31108,cffecc00,4,0,cffecb70) at swap_pager_putpages+0x2a8
default_pager_putpages(c1a31108,cffecc00,4,0,cffecb70) at default_pager_putpages+0x18
vm_pageout_flush(cffecc00,4,0,0,cffecbdc) at vm_pageout_flush+0x112
vm_pageout_clean(c151ffb0) at vm_pageout_clean+0x2a5
vm_pageout_scan(0) at vm_pageout_scan+0x543
vm_pageout(0,cffecd48,0,c072a8f0,0) at vm_pageout+0x2d2
fork_exit(c072a8f0,0,cffecd48) at fork_exit+0x98
fork_trampoline() at fork_trampoline+0x8
--- trap 0x1, eip = 0, esp = 0xcffecd7c, ebp = 0 ---

-Nate