LOR in FreeBSD 8.1 w/ IPv6

[Vijay Singh]

Hi, the following LOR is reported on my system:

f6070c-01% lock order reversal:
 1st 0xffffff00043c0c18 e5a:rx(0) (e5a:rx(0)) @ sys/dev/e1000/if_em.c:1607
 2nd 0xffffffff80f10780 in6_multi_mtx (in6_multi_mtx) @
sys/netinet6/in6_var.h:734
KDB: stack backtrace:
kdb_backtrace() at kdb_backtrace+0x3e
witness_releaseok() at witness_releaseok+0x1934
witness_checkorder() at witness_checkorder+0xafc
_mtx_lock_flags() at _mtx_lock_flags+0xef
icmp6_input() at icmp6_input+0x15ed
icmp6_input() at icmp6_input+0x292
ip6_input() at ip6_input+0x1156
netisr_dispatch_src() at netisr_dispatch_src+0x168
netisr_dispatch() at netisr_dispatch+0x20
ether_demux() at ether_demux+0x253
ether_ipfw_chk() at ether_ipfw_chk+0xb66
ether_ipfw_chk() at ether_ipfw_chk+0xbbd
netisr_dispatch_src() at netisr_dispatch_src+0x168
netisr_dispatch() at netisr_dispatch+0x20
ether_ipfw_chk() at ether_ipfw_chk+0xc2d
busdma_map_sg_vec() at busdma_map_sg_vec+0xa611
busdma_map_sg_vec() at busdma_map_sg_vec+0x2f58
taskqueue_unblock() at taskqueue_unblock+0x235
taskqueue_thread_loop() at taskqueue_thread_loop+0x73
fork_exit() at fork_exit+0x166
fork_trampoline() at fork_trampoline+0xe
--- trap 0, rip = 0, rsp = 0xffffff8062691d30, rbp = 0 ---

Is it known?

-vijay