Watchdog not being disabled while dumping core

[Erik Trulsson]

On Mon, Aug 23, 2010 at 04:07:47AM -0700, Xin LI wrote:
> On Mon, Aug 23, 2010 at 3:34 AM, Jeremy Chadwick
> <freebsd at jdc.parodius.com> wrote:
> > PR bin/145183, opened in 2010 (not sure if this is the same):
> > http://www.freebsd.org/cgi/query-pr.cgi?pr=bin/145183
> 
> Speaking for this I think we can do it by issuing an explicit
> watchdog(8) command on shutdown (like, set the timeout to several
> minutes) in /etc/rc.d/watchdog's shutdown section.  This would be
> trivial to implement.

No, it would not be trivial to implement (at least not if you want it
to actually work correctly.)  The reason for that is that at least some
(perhaps even most) hardware watchdog devices do not support so long
timeouts.

I know for example that the watchdog in the ixp425 CPU has a maximum
timeout of 65 seconds.  Reading the manpage for ichwd(4) it seems that
it has maximum timeout of about 37 seconds.

I suspect that other hardware watchdogs have similar limits, which
leads to the conclusion that one should not assume watchdog timeouts
longer than maybe 30 seconds to be supported.





-- 
<Insert your favourite quote here.>
Erik Trulsson
ertr1013 at student.uu.se