watchdog end-user interface

[Alfred Perlstein]

On 10/19/16 4:18 AM, Poul-Henning Kamp wrote:
> --------
> In message <ec3dfab5-c3bc-e9e5-181e-8c2704f60acd at FreeBSD.org>, Andriy Gapon wri
> tes:
>
>> I want to question if those options really belong to watchdogd.
>> When a watchdog timer expires that results in a system-wide action (like a
>> system reset).  To me, that implies that there should be a single system-wide
>> configuration point.  And I am not sure that the daemon is the best choice for it.
> The reason I originally put it in a daemon, was to have the watchdog
> implicitly test the kernels ability to schedule trivial processes.
>
> It used to be, and may still be so that, there are deadlocks where
> the kernel was twiddling its thumbs but userland did not progress.
> Typical triggers for this are disk-I/O errors, corrupt filesystems,
> memory overcommit etc.
>
> A kernel-only watchdog patter would not trigger in that case.
Exactly.

-Alfred