Acquiring lockmgr lock "ufs" with the following non-sleepable locks held:

Got this warning running an ibcs2_coff binary on today's -current:

Acquiring lockmgr lock "ufs" with the following non-sleepable locks held:
exclusive sleep mutex system map r = 0 (0xc103b060) locked _at_ vm/vm_map.c:2869
Stack backtrace:
backtrace(c096ad7c,edca5748,115,1,c0947ff8) at backtrace+0x17
witness_warn(5,c093aae8,c087ab88,c0887eb9,c0946320) at witness_warn+0x1c5
lockmgr(c7ed85c0,1030041,c7ed8514,c7ef5540,1030041) at lockmgr+0xd9
ufs_lock(edca57ac,edca57c8,c06ce702,edca57ac,c7ed8514) at ufs_lock+0x4d
ufs_vnoperate(edca57ac,c7ed8514,edca57c0,c068c4d7,c096ad68) at ufs_vnoperate+0x18
vn_lock(c7ed8514,1030041,c7ef5540,c06c206c,c7ef3084) at vn_lock+0xf2
vget(c7ed8514,1030041,c7ef5540,45c,0) at vget+0x116
vnode_pager_lock(c7ef3084,0,c0890f91,125,edca58a8) at vnode_pager_lock+0x141
vm_fault(c103b000,edcc8000,1,0,c7ef5540) at vm_fault+0x281
trap_pfault(edca5990,0,edcc8000,0,edcc8000) at trap_pfault+0x172
trap(c1030018,c7ef0010,120010,434000,edcc8000) at trap+0x353
calltrap() at calltrap+0x5
--- trap 0xc, eip = 0xc0809bdc, esp = 0xedca59d0, ebp = 0xedca5a20 ---
slow_copyout(c7c51674,c7ed8514,ee3b4,4003b4,5d074) at slow_copyout+0x4
exec_coff_imgact(edca5b8c,0,c0879fb3,148,c0946320) at exec_coff_imgact+0x3f5
kern_execve(c7ef5540,8107204,8107230,810b004,0) at kern_execve+0x3cc
execve(c7ef5540,edca5d14,c,7,3) at execve+0x30
syscall(2f,2f,2f,8107204,8107230) at syscall+0x2a0
Xint0x80_syscall() at Xint0x80_syscall+0x1d
--- syscall (59), eip = 0x807c22f, esp = 0xbfbfc91c, ebp = 0xbfbfc938 ---

-- 
	Dan Nelson
	dnelson_at_allantgroup.com