non-sleepable locks held (xl0)

Not sure if this is reported already, but i got this on a recently cvsuped
-current system while booting.

FreeBSD 6.0-CURRENT #1: Mon May 23 16:17:04 EDT 2005
    root_at_fbsd.wettoast.net:/usr/obj/usr/src/sys/DP
WARNING: WITNESS option enabled, expect reduced performance.
Timecounter "i8254" frequency 1193182 Hz quality 0
CPU: AMD Athlon(tm) Processor (1410.21-MHz 686-class CPU)
  Origin = "AuthenticAMD"  Id = 0x644  Stepping = 4
Features=0x183f9ff<FPU,VME,DE,PSE,TSC,MSR,PAE,MCE,CX8,SEP,MTRR,PGE,MCA,CMOV,PAT,PSE36,MMX,FXSR>
  AMD Features=0xc0440000<RSVD,AMIE,DSP,3DNow!>
real memory  = 536788992 (511 MB)

xl0: <3Com 3c905C-TX Fast Etherlink XL> port 0x9400-0x947f mem
0xe3800000-0xe380007f irq 5 at device 9.0 on pci0

---
Starting dhclient.
taskqueue_drain with the following non-sleepable locks held:
exclusive sleep mutex xl0 (network driver) r = 0 (0xc16512fc) locked _at_
/usr/src/sys/pci/if_xl.c:3148
KDB: stack backtrace:
kdb_backtrace(c06e334c,d54c3b6c,1,1,1) at kdb_backtrace+0x2e
witness_warn(5,0,c064a857,c159caf8,c0517b6b) at witness_warn+0x1b3
taskqueue_drain(c1552d00,c1651320,c06544df,cc2,c164f000) at
taskqueue_drain+0x2b
xl_stop(c164f000,1,c06544df,af4,0) at xl_stop+0x58
xl_init_locked(c164f000,0,c06544df,c4c,0) at xl_init_locked+0x43
xl_ioctl(c164f000,80206910,c1867560,1,c0646d61) at xl_ioctl+0x1c1
ifhwioctl(80206910,c164f000,c1867560,c159ca80,c04e1ac7) at ifhwioctl+0x368
ifioctl(c1869530,80206910,c1867560,c159ca80,1) at ifioctl+0xe6
soo_ioctl(c17df990,80206910,c1867560,c1551c80,c159ca80) at soo_ioctl+0x3bf
ioctl(c159ca80,d54c3d04,c,407,3) at ioctl+0x462
syscall(3b,3b,3b,4,1) at syscall+0x265
Xint0x80_syscall() at Xint0x80_syscall+0x1f
--- syscall (54, FreeBSD ELF32, ioctl), eip = 0x280cb8bf, esp =
0xbfbfe57c, ebp = 0xbfbfe5c8 ---
xl0: link state changed to UP
taskqueue_drain with the following non-sleepable locks held:
exclusive sleep mutex xl0 (network driver) r = 0 (0xc16512fc) locked _at_
/usr/src/sys/pci/if_xl.c:2791
KDB: stack backtrace:
kdb_backtrace(c06e334c,d54c3af0,1,1,1) at kdb_backtrace+0x2e
witness_warn(5,0,c064a857,c159caf8,c0517b6b) at witness_warn+0x1b3
taskqueue_drain(c1552d00,c1651320,c06544df,cc2,c164f000) at
taskqueue_drain+0x2b
xl_stop(c164f000,1,c06544df,af4,0) at xl_stop+0x58
xl_init_locked(c164f000,0,c06544df,ae7,c164f000) at xl_init_locked+0x43
xl_init(c164f000,c0646d61,18a,8020690c,c17c9500) at xl_init+0x3d
ether_ioctl(c164f000,8020690c,c17c9500,c06726a8,0) at ether_ioctl+0x69
xl_ioctl(c164f000,8020690c,c17c9500,1,c04e4384) at xl_ioctl+0x363
in_ifinit(c164f000,c17c9500,c16cd3d0,0,1) at in_ifinit+0x1b5
in_control(c1869530,8040691a,c16cd3c0,c164f000,c159ca80) at in_control+0x905
ifioctl(c1869530,8040691a,c16cd3c0,c159ca80,2) at ifioctl+0x1e1
soo_ioctl(c17df990,8040691a,c16cd3c0,c1551c80,c159ca80) at soo_ioctl+0x3bf
ioctl(c159ca80,d54c3d04,c,407,3) at ioctl+0x462
syscall(3b,3b,3b,80563a0,0) at syscall+0x265
Xint0x80_syscall() at Xint0x80_syscall+0x1f
--- syscall (54, FreeBSD ELF32, ioctl), eip = 0x280cb8bf, esp =
0xbfbfe5cc, ebp = 0xbfbfee38 ---
em0: link state changed to UP
taskqueue_drain with the following non-sleepable locks held:
exclusive sleep mutex xl0 (network driver) r = 0 (0xc16512fc) locked _at_
/usr/src/sys/pci/if_xl.c:2791
KDB: stack backtrace:
kdb_backtrace(c06e3314,d54d5af0,1,1,1) at kdb_backtrace+0x2e
witness_warn(5,0,c064a857,c16064f8,c0517b6b) at witness_warn+0x1b3
taskqueue_drain(c1552d00,c1651320,c06544df,cc2,c164f000) at
taskqueue_drain+0x2b
xl_stop(c164f000,1,c06544df,af4,0) at xl_stop+0x58
xl_init_locked(c164f000,0,c06544df,ae7,c164f000) at xl_init_locked+0x43
xl_init(c164f000,c0646d61,18a,8020690c,c17c9100) at xl_init+0x3d
ether_ioctl(c164f000,8020690c,c17c9100,c06726a8,0) at ether_ioctl+0x69
xl_ioctl(c164f000,8020690c,c17c9100,1,c04e4384) at xl_ioctl+0x363
in_ifinit(c164f000,c17c9100,c17ba050,0,1) at in_ifinit+0x1b5
in_control(c1869298,8040691a,c17ba040,c164f000,c1606480) at in_control+0x905
ifioctl(c1869298,8040691a,c17ba040,c1606480,2) at ifioctl+0x1e1
soo_ioctl(c17df1b0,8040691a,c17ba040,c1551c80,c1606480) at soo_ioctl+0x3bf
ioctl(c1606480,d54d5d04,c,407,3) at ioctl+0x462
syscall(3b,3b,3b,80563a0,bfbfebaf) at syscall+0x265
Xint0x80_syscall() at Xint0x80_syscall+0x1f
--- syscall (54, FreeBSD ELF32, ioctl), eip = 0x280cb8bf, esp =
0xbfbfe1bc, ebp = 0xbfbfea28 ---
xl0: flags=8843<UP,BROADCAST,RUNNING,SIMPLEX,MULTICAST> mtu 1500
        options=9<RXCSUM,VLAN_MTU>
        inet x.x.x.195 netmask 0xfffffe00 broadcast x.x.x.255
        ether 00:01:03:d4:4c:07
        media: Ethernet autoselect (100baseTX <full-duplex>)
        status: active