NAME
swwdog
- software watchdog timer
SYNOPSIS
pseudo-device swwdog[ count]
DESCRIPTION
The
swwdog
driver provides a software watchdog timer that works with
wdogctl(8).
If the timer expires, the system reboots unless the variable
swwdog_panic
is non-zero; if it is, the system will panic instead.
The default period of
swwdog
is 60 seconds.
SEE ALSO
wdogctl(8)
HISTORY
The
swwdog
driver was written by
Steven M. Bellovin
.
BUGS
Although more than one
swwdog
timer can be configured, it's a pointless thing to do, since only
one watchdog timer can be active at any given time.
Arguably, this is a bug in the watchdog timer framework.
Kernel tickle mode is useless with
swwdog
and arguably should be rejected, since both it and
this driver rely on the same callout mechanism; if one is
blocked, almost certainly the other is as well.
The alarm option to
wdogctl(8)
isn't implemented.