Re: [PATCH 0/8] watchdog: Add support for keepalives triggered by infrastructure

[David Teigland <teigland@redhat.com>]

On Wed, Aug 05, 2015 at 10:41:51AM -0700, Guenter Roeck wrote:
> Not really. The heartbeats will be generated such that the watchdog expires
> no later that <last heartbeat from userspace + configured timeout>. I discussed
> this already with Uwe; he had the same concern. This isn't in the current
> version of the patch set, but it will be in the next version. That means
> that nothing will change from user space perspective.

Sounds good, thanks.

> >A related issue from some years ago is the unfortunate fact that closing
> >the watchdog device also generates a heartbeat.  I'd like to disable that
> >also, and submitted a patch for it here:
> >http://www.spinics.net/lists/linux-watchdog/msg01477.html
> >
> 
> That is a different issue, though, and unrelated to this patch set.
> Wim had a good point there: Presumably the problem you are trying to solve
> applies to the entire system, not to a specific watchdog. What you are looking
> for looks more like a system parameter, not like something to set with an ioctl
> message. The reason here is that you'd still want to be able to use standard
> applications such as systemd or watchdogd to trigger heartbeats, and not depend
> on your own.

I'd need this behavior when the system is running my program (sanlock with
wdmd), which uses /dev/watchdog.  No other programs (systemd or watchdogd)
could be using /dev/watchdog at the same time.

Dave