can the hardware watchdog reboot a hung kernel?

[Daniel Braniss]

> On 14 Nov 2019, at 17:28, Eugene Grosbein <eugen at grosbein.net> wrote:
> 
> 14.11.2019 21:52, Daniel Braniss wrote:
> 
>> hi,
>> I have serveral hundred Nano-pi NEO running, and sometimes they hang, since there is no console
>> available, the only solution is to do a power cycle - not so easy since they are distributed in three buildings :-)
>> 
>> I am looking at the watchdog stuff, but it seems that what I want is not supported, i.e.
>> 	reboot the kernel when hung 
>> 
>> wishful thinking?
> 
> It's possible if the hardware has such a watchdog and kernel subsystem watchdog(4) supports it.
> rc.conf(5) manual page describes watchdogd_enable option.
> 

yes, but it relys  on user land, what if the kernel is hung?