Sleeping on "objtrm" with non-sleepable locks held

Hola senores!

I got this on the console output of my Sun E250 running 
a -current from ~July 12th.  The machine continued
running after displaying this.




e250#
e250# Sleeping on "objtrm" with the following non-sleepablelocks held:
exclusive sleep mutex system map r = 0 (0xfffff80067e92098) locked _at_ /usr/src/sys/vm/vm_map.c:2192
lock order reversal
 1st 0xfffff80067e92098 system map (system map) _at_ /usr/src/sys/vm/vm_map.c:2192
 2nd 0xc0354d70 Giant (Giant) _at_ /usr/src/sys/kern/kern_synch.c:312
Stack backtrace:
_mtx_lock_flags() at _mtx_lock_flags+0xa0
msleep() at msleep+0x6a8
vm_object_pip_wait() at vm_object_pip_wait+0x48
vm_object_terminate() at vm_object_terminate+0x30
vm_object_deallocate() at vm_object_deallocate+0x374
vm_map_entry_delete() at vm_map_entry_delete+0x3c
vm_map_delete() at vm_map_delete+0x32c
vm_map_remove() at vm_map_remove+0x44
kmem_free() at kmem_free+0x20
pipe_free_kmem() at pipe_free_kmem+0x98
pipeclose() at pipeclose+0x124
pipe_close() at pipe_close+0x20
fdrop_locked() at fdrop_locked+0x134
fdrop() at fdrop+0x20
closef() at closef+0x1f8
close() at close+0x168
syscall() at syscall+0x2ac
-- syscall (6, FreeBSD ELF64, close) %o7=0x10706c --
userland() at 0x120128
user trace: trap %o7=0x10706c
pc 0x120128, sp 0x7fdffffdd41
pc 0x107164, sp 0x7fdffffde01
pc 0x1090cc, sp 0x7fdffffdec1
pc 0x10c3f4, sp 0x7fdffffdf91
pc 0x10b22c, sp 0x7fdffffe061
pc 0x1001dc, sp 0x7fdffffedd1
pc 0, sp 0x7fdffffee91
done

e250# 


I googled and searched the mailing list archive of the -current list.
I didn't see anyone reporting this for 5.x-current, and the only thread
I found was from July of 1999.