How to debug hard lockup issue

Thu Aug 2 04:34:13 EDT 2012

On Thu, Aug 02, 2012 at 03:59:36PM +0800, Lin Ming wrote:
> On Thu, Aug 2, 2012 at 3:15 PM, Uwe Kleine-König
> <u.kleine-koenig at pengutronix.de> wrote:
> > Hello,
> >
> > On Thu, Aug 02, 2012 at 11:03:31AM +0800, Lin Ming wrote:
> >> I encountered a hard lockup on a armv5 board with 2.6.32 kernel.
> >> There is no any message output since it is hard lockup.
> >>
> >> I tried watchdog, but watchdog can only reset the board. I still can't
> >> get any info.
> >>
> >> The hard lockup is possibly because kernel blocked/looped with
> >> interrupts disabled.
> >>
> >> Is there any non-maskable interrupt I can use to dump the kernel stack?
> >> Or any other hint?
> > Try enabling various debug options. The following come to (my) mind:
> >
> > CONFIG_DETECT_HUNG_TASK
> > CONFIG_PROVE_LOCKING
> > CONFIG_DEBUG_ATOMIC_SLEEP
> > CONFIG_MAGIC_SYSRQ
> 
> These debug options are already enabled.
> But it doesn't help.
then if you don't have a hardware debugger handy you can try

	https://lkml.org/lkml/2012/5/26/83

Best regards
Uwe

-- 
Pengutronix e.K.                           | Uwe Kleine-König            |
Industrial Linux Solutions                 | http://www.pengutronix.de/  |