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Re: Diagnostics

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Hi George,

[Hope all is well with you and at home]

On 10/18/2024 2:42 PM, George Neuner wrote:
> WRT Don's question, I don't know the answer, but I suspect runtime
> diagnostics are /not/ routinely implemented for devices that are not
> safety critical.  Reason: diagnostics interfere with operation of
> <whatever> they happen to be testing.  Even if the test is at low(est)
> priority and is interruptible by any other activity, it still might
> cause an unacceptable delay in a real time situation.

But, if you *know* when certain aspects of a device will be "called on",
you can take advantage of that to schedule diagnostics when the device is
not "needed".  And, in the event that some unexpected "need" arises,
can terminate or suspend the testing (possibly rendering the effort
moot if it hasn't yet run to a conclusion).

E.g., I scrub freed memory pages (zero fill) so information doesn't
leak across protection domains.  As long as some minimum number
of *scrubbed* pages are available for use "on demand", why can't
I *test* the pages yet to be scrubbed?

If I don't *expect* a car to pull up and call for the garage door
to be opened, why can't I play with the lighting to verify that
the cameras located within *notice* changes?

If there is no anticipated short term need for irrigation, why
can't I momentarily activate individual valves and watch to see that
the expected amount of water is flowing?

If a node is powered down due to lack of expected immediate need,
why not power it *up* and run diagnostics on it?  Powering it back
down once completed -- *or*, aborting the diagnostics if the node
is called on to be powered up?

>  To ensure 100%
> functionality at all times effectively requires use of redundant
> hardware - which generally is too expensive for a non safety critical
> device.

Apparently, there is noise about incorporating such hardware into
*automotive* designs (!).  I would have thought the time between
POSTs would have rendered that largely ineffective.  OTOH, if
you imagine a failure can occur ANY time, then "just after
putting the car in gear" is as good (bad!) a time as any!

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Diagnostics Don Y <blockedofcourse@foo.invalid> - 2024-10-12 12:58 -0700
  Re: Diagnostics antispam@fricas.org (Waldek Hebisch) - 2024-10-18 20:30 +0000
    Re: Diagnostics George Neuner <gneuner2@comcast.net> - 2024-10-18 17:42 -0400
      Re: Diagnostics Don Y <blockedofcourse@foo.invalid> - 2024-10-18 15:30 -0700
        Re: Diagnostics antispam@fricas.org (Waldek Hebisch) - 2024-10-19 01:50 +0000
          Re: Diagnostics Don Y <blockedofcourse@foo.invalid> - 2024-10-18 19:38 -0700
            Re: Diagnostics antispam@fricas.org (Waldek Hebisch) - 2024-10-19 03:53 +0000
              Re: Diagnostics Don Y <blockedofcourse@foo.invalid> - 2024-10-18 21:17 -0700
                Re: Diagnostics antispam@fricas.org (Waldek Hebisch) - 2024-10-24 17:52 +0000
                Re: Diagnostics Don Y <blockedofcourse@foo.invalid> - 2024-10-24 14:49 -0700
        Re: Diagnostics David Brown <david.brown@hesbynett.no> - 2024-10-19 14:07 +0200
        Re: Diagnostics George Neuner <gneuner2@comcast.net> - 2024-10-19 15:25 -0400
          Re: Diagnostics Don Y <blockedofcourse@foo.invalid> - 2024-10-19 14:32 -0700
            Re: Diagnostics Don Y <blockedofcourse@foo.invalid> - 2024-10-23 05:53 -0700
        Re: Diagnostics Nioclásán Caileán de Ghlostéir <Master_Fontaine_is_dishonest@Strand_in_London.Gov.UK> - 2024-10-20 19:15 +0200
      Re: Diagnostics antispam@fricas.org (Waldek Hebisch) - 2024-10-19 01:25 +0000
      Re: Diagnostics David Brown <david.brown@hesbynett.no> - 2024-10-19 13:57 +0200
    Re: Diagnostics Don Y <blockedofcourse@foo.invalid> - 2024-10-18 15:15 -0700
      Re: Diagnostics antispam@fricas.org (Waldek Hebisch) - 2024-10-19 03:00 +0000
        Re: Diagnostics Don Y <blockedofcourse@foo.invalid> - 2024-10-18 21:05 -0700
          Re: Diagnostics antispam@fricas.org (Waldek Hebisch) - 2024-10-19 13:53 +0000
            Re: Diagnostics Don Y <blockedofcourse@foo.invalid> - 2024-10-19 09:55 -0700
              Re: Diagnostics antispam@fricas.org (Waldek Hebisch) - 2024-10-24 16:34 +0000
                Re: Diagnostics Don Y <blockedofcourse@foo.invalid> - 2024-10-24 14:28 -0700
          Re: Diagnostics George Neuner <gneuner2@comcast.net> - 2024-10-19 15:58 -0400
            Re: Diagnostics Don Y <blockedofcourse@foo.invalid> - 2024-10-19 16:26 -0700
              Re: Diagnostics Nioclásán Caileán de Ghlostéir <Master_Fontaine_is_dishonest@Strand_in_London.Gov.UK> - 2024-10-20 20:08 +0200
          Re: Diagnostics Nioclásán Caileán de Ghlostéir <Master_Fontaine_is_dishonest@Strand_in_London.Gov.UK> - 2024-10-20 19:11 +0200
            Re: Diagnostics George Neuner <gneuner2@comcast.net> - 2024-10-20 15:44 -0400
              Re: Diagnostics Nioclásán Caileán de Ghlostéir <Master_Fontaine_is_dishonest@Strand_in_London.Gov.UK> - 2024-10-20 23:14 +0200

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