I'm running into an issue with vnlock() showing up from time to time
basically causing the machine to have to be reset.  I'm using
1.6.1rc2 with softdeps

trace from the debugger reports:

db> trace
cpu_Debugger() at cpu_Debugger+0x4
comintr() at comintr+0x168
alpha_shared_intr_dispatch() at alpha_shared_intr_dispatch+0x6c
sio_iointr() at sio_iointr+0x68
interrupt() at interrupt+0x27c
XentInt() at XentInt+0x1c
--- interrupt (from ipl 1) ---
nqsrv_getlease() at nqsrv_getlease+0x510
genfs_lease_check() at genfs_lease_check+0x58
vn_read() at vn_read+0x80
dofileread() at dofileread+0xd8
sys_read() at sys_read+0xbc
syscall_plain() at syscall_plain+0x154
XentSys() at XentSys+0x58
--- syscall (3) ---
--- user mode ---
db> con
tlp0: receive ring overrun
load: 3.55  cmd: login 193 [vnlock] 0.04u 0.04s 0% 0k
load: 3.55  cmd: login 193 [vnlock] 0.04u 0.04s 0% 0k