Hi Paul,

In kernel boot tests with the attached config, I find the 3.5-rc2+
kernels all hang here:

[    6.522546] rcu-torture:--- Start of test: nreaders=2
nfakewriters=4 stat_interval=0 verbose=0 test_no_idle_hz=0
shuffle_interval=3 stutter=5 irqreader=1 fqs_duration=0 fqs_holdoff=0
fqs_stutter=3 test_boost=1/0 test_boost_interval=7
test_boost_duration=4 shutdown_secs=0 onoff_interval=0 onoff_holdoff=0

And interestingly, the boot option 'rcutorture.rcutorture_runnable=0'
cannot disable the boot time torture test.

If it's a new problem to you, I'll try bisecting it.

Thanks,
Fengguang