Re: [PATCH 1/1] Introduce Intel RAPL cooling device driver

From: Jacob Pan
Date: Tue Apr 02 2013 - 19:53:48 EST


On Tue, 2 Apr 2013 16:00:42 -0700
Greg KH <gregkh@xxxxxxxxxxxxxxxxxxx> wrote:

> And, one final complaint, never use "raw" kobjects, for loads of good
> reasons, not the least being you just prevented userspace from seeing
> what is happening with your devices. Use the driver model, that's
> what it is there for, if you need "sub children", or subdirectories.
I chose to use to kobjects for the reason that userspace can see the
device linking more clearly.
Let me try to paraphrase, I have two options:
1. if I use the platform device model instead of raw kobjects, I would
have one platform device for each rapl domain. Then link individual
platform device with the generic thermal layer sysfs.

2. In the current patch, I have one platform driver, then expose per
domain kobject that can be linked to the generic thermal layer. Common
attributes of all domains are grouped under the kset.

I did consider both options. I thought using #2 option is better since
it allow user to discover the topologies easier by following the
sysfs link. If i use use #1, it would be hard to expose the common
attributes and more code too. Perhpas I misread
Documentation/kobjects.txt which i thought kobject/kset are perfect for
presenting situation like this.

--
Thanks,

Jacob
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/