Is the linux userspace qualified to trigger a watchdog?

[00schneider]

Hello,

On my embedded board I have a watchdog which does a reset when it is not triggered longer than 1.5 seconds. I have a kernel module that controls that watchdog and I have the opportunity to trigger the watchdog from userspace via sysctl.
From time to time the board makes a reset (by watchdog) and I don't exactly know why.

I wrote a little program in userspace which contains nothing but a usleep(50) and time measurement before and after the operation (with clock_gettime(CLOCK_REALTIME, &mytime) ) and over 5 days I measured maximum values about 3 seconds.

So my question is: Is the linux userspace qualified at all to trigger a watchdog?