How to debug hard lockup issue

[Lin Ming]

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.

Thanks.