Watchdog thread activity

Watchdog thread activity

[Sriram V]

Hi,

I am running Linux along with image processing on my system.
Most watchdogs i have seen previously, has a 30 second/60 second
timer. The watchdog we have used currently has a fixed timeout value
of 1.6 seconds.

I wanted to check if Linux can pet the watchdog say every 1 second.
Won't it over-load the system if i used mod_timer/workqueue?

However, I think, Some activity in the system might cause false-resets
due to the cpu being busy in other tasks.

Therefore, i wanted to check what is the safe minimum duration which
will avoid false-resets.

Thanks,
sriram

Re: Watchdog thread activity

[Guenter Roeck]

On Tue, Nov 14, 2017 at 08:34:03PM +0530, Sriram V wrote:
> Hi,
> 
> I am running Linux along with image processing on my system.
> Most watchdogs i have seen previously, has a 30 second/60 second
> timer. The watchdog we have used currently has a fixed timeout value
> of 1.6 seconds.
> 
> I wanted to check if Linux can pet the watchdog say every 1 second.
> Won't it over-load the system if i used mod_timer/workqueue?
> 
> However, I think, Some activity in the system might cause false-resets
> due to the cpu being busy in other tasks.
> 
> Therefore, i wanted to check what is the safe minimum duration which
> will avoid false-resets.
> 

Why don't you just use the existing watchdog subsystem infrastructure,
which does support that use case ? Do you have any evidence that it fails
under some circumstances ? If so, can you let us know how to trigger that
failure so we can understand it and find a possible fix ?

Thanks,
Guenter