RE: [RFC 00/10] Introduce In Field Scan driver

Luck, Tony
2022-03-15T14:59:11Z

>> This seems a novel use of uevent ... is it OK, or is is abuse?
>
> Don't create "novel" uses of uevents. They are there to express a
> change in state of a device so that userspace can then go and do
> something with that information. If that pattern fits here, wonderful.

Maybe Dan will chime in here to better explain his idea. I think for
the case where the core test fails, there is a good match with uevent.
The device (one CPU core) has changed state from "working" to
"untrustworthy". Userspace can do things like: take the logical CPUs
on that core offline, initiate a service call, or in a VMM cluster environment
migrate work to a different node.

> I doubt you can report "test results" via a uevent in a way that the
> current uevent states and messages would properly convey, but hey, maybe
> I'm wrong.

But here things get a bit sketchy. Reporting "pass", or "didn't complete the test"
isn't a state change. But it seems like a poor interface if there is no feedback
that the test was run. Using different methods to report pass/fail/incomplete
also seems user hostile.

> good luck!
Thanks ... we may need it :-)

-Tony