Take the 2-minute tour ×

How does the /dev/watchdog timer exactly work? I found a description here and it says that once I open the file from an application I need to update it every 10 seconds. I was wondering is this a hard limit? For example what if I update it in 11 seconds for instance?
Could someone explain the behavior to me please?
Because there are no "hard limits" in the thread scheduling so that I am certain that the file is updated in exactly 10 sec. stricty unless I use e.g. a spin loop instead of a sleep

share|improve this question
Why the downvote? –  Jim Feb 19 '13 at 7:03
I don't know how watchdog exactly works. But kernel features are usually well documented. For example in case of the watchdog there is a subdirectory called '/Documentation/watchdog' in the kernel source. There you should find a nice description –  mauro.stettler Feb 19 '13 at 7:24
@mauro.stettler:Where is the kernel source?For example I have a sles installed.Is it in the file system this documentation? –  Jim Feb 19 '13 at 7:31
if you installed the kernel-source rpm, then it is usually in /usr/src/linux. otherwise you can get it from kernel.org –  mauro.stettler Feb 19 '13 at 7:32

Your Answer



Browse other questions tagged or ask your own question.