NMI watchdog functionality on Freebsd

[John Baldwin]

On Tuesday, January 22, 2013 5:40:55 pm Sushanth Rai wrote:
> Hi,
> 
> Does freebsd have some functionality similar to  Linux's NMI watchdog ? I'm 
aware of ichwd driver, but that depends to WDT to be available in the 
hardware. Even when it is available, BIOS needs to support a mechanism to 
trigger a OS level recovery to get any useful information when system is 
really wedged (with interrupt disabled). 
> 
> With Linux's NMI, APIC is programmed to periodically generate NMI and the OS 
NMI handler can check for some counters and invoke panic if the counters are 
not updated for a while. 

We currently use the local APIC timer as a timer with a normal interrupt.  
There's no reason you couldn't add a mode to make the local APIC timer operate 
in this fashion however.

-- 
John Baldwin