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

Luck, Tony
2022-03-14T23:10:42Z

On Tue, Mar 01, 2022 at 09:14:26PM +0100, Greg KH wrote:
> On Tue, Mar 01, 2022 at 09:10:20PM +0100, Greg KH wrote:
> > On Tue, Mar 01, 2022 at 11:54:47AM -0800, Jithu Joseph wrote:
> > > Note to Maintainers:
> > > Requesting x86 Maintainers to take a look at patch01 as it
> > > touches arch/x86 portion of the kernel. Also would like to guide them
> > > to patch07 which sets up hotplug notifiers and creates kthreads.
> > >
> > > Patch 2/10 - Adds Documentation. Requesting Documentation maintainer to review it.
> > >
> > > Requesting Greg KH to review the sysfs changes added by patch08.
> >
> > "RFC" means you are not comfortable submitting the changes yet, so you
> > don't need my review at this point in time. Become confident in your
> > changes before asking for others to review the code please.
>
> Hint, it needs work, sysfs_emit() for one thing, lack of reference
> counting on your cpu objects is another...

Greg,

Thanks for the comments. They triggered a bunch of internal
re-thinking of the interface. One idea that has some traction
(Credit/Blame: Dan Williams) is to:

1) Don't put anything in /sys/devices/system/cpu/*
2) Driver creates some info/control files in its own
corner of /sys/devices/.../ifs
3) No per-cpu files ... run a test with:
# echo ${cpu} > /sys/devices/.../ifs/run_test
4) No test result files.
When tests complete they report using uevents

Using uevent to report means that we can easily have
mutiple parts to the result (pass/fail/incomplete status, as well
as diagnostic details about the reason for the failure,
or why the test was not completed).

This seems a novel use of uevent ... is it OK, or is is abuse?

Thanks

-Tony