Naming DBus paths of CPU objects

[Ed Tanous]

On Mon, Aug 31, 2020 at 10:55 AM i.kononenko <i.kononenko at yadro.com> wrote:
>
> Hi,
>
> I'm working on improving of the OpenBMC RedFISH API. In particular, the endpoint of the Processor.
> To provide all the properties of the applied RedFISH schema, we need to get from
> DBus everything related to the CPU object.
> It can be CPU, Sensor CPU temp, Sensors Core CPU, etc.


I'm a little confused.  The Processor schema doesn't have a Thermal
property (did they add one?) so CPU temperatures and core temps would
need to go under an equivalent Assembly or Chassis.  I think today for
some platforms they're added under the baseboard, which isn't
"correct" but is close enough.  Can you talk a little more about what
you're wanting to accomplish in your improvements?  What would the end
result look like?

>
>
> However, some services have different names for the same physical processor.
> In particular it is about `entity-manager`, `dbus-sensros`, `smbios-mdr_v2`.
> `Smbios-mdr_v2` (just like `hwmon`) names the processor, indexing
> it from 0; in `entity-manager` and `dbus-sensor` indexing starts from 1.
>
> I want to add dbus-associations between all Processor's object,
> but for that I think we need to adopt a naming convention for the same DBus objects.


Can you talk about why you need this?  Keep in mind, there are lots of
systems that have processors on add in cards, or separate
accelerators.  Making the statement "all" makes me think you're
wanting to make a blanket association from system->processor, which
I'm not sure we can do as a generalization without breaking those use
cases (which admittedly aren't modeled very well today).  I would hope
we don't need to rely on a common naming convention to do it.

>
>
> I like to index it from 0, just like doing that the `hwmon`, for example.


I completely agree that we should standardize the naming convention
where we can, the only problem here is that the overarching goal is
that we match the silkscreen mask on the board, some of which zero
index, some of which one index.  With that said, I know that a lot of
the existing configs don't currently match the silkscreen.
smbios-mdr_v2 to my understanding should be using 1 indexing.

>
>
> --
> Best Regards!
> Igor Kononenko