Re: unparseable, undocumented /sys/class/drm/.../pstate

[Greg KH <greg@kroah.com>]

On Mon, Jun 23, 2014 at 04:18:39PM -0400, Ilia Mirkin wrote:
> On Mon, Jun 23, 2014 at 4:15 PM, Pavel Machek <pavel@ucw.cz> wrote:
> > Hi!
> >
> >> >> >> > I guess better interface would be something like
> >> >> >> >
> >> >> >> > pstate/07/core_clock_min
> >> >> >> >           core_clock_max
> >> >> >> >           memory_clock_min
> >> >> >> >           memory_clock_max
> >> >> >> >
> >> >> >> > and then pstate/active containing just the number of active state?
> >> >
> >> >> Could we just say that the format of this file is one-per-line of
> >> >>
> >> >> level: information-for-the-user
> >> >
> >> > But it is not.
> >>
> >> But it is...
> >>
> >> > Management tools will want to parse it, sooner or
> >> > later.  What is wrong with solution described above?
> >>
> >> It is complex and annoying to the people that will actually use it.
> >
> > grep -r . pstate/ is actually not that bad...
> 
> While that's a clever trick that anyone who's done a bunch of stuff
> with sysfs knows, I doubt the average linux user could come up with
> that on their own. I know I didn't.

That's fine, why would an "average" Linux user ever need to poke around
in sysfs?  Again, please describe what you are wanting to have exported
to userspace, and what userspace is supposed to do with that
information, before worrying about the actual sysfs file layout.

greg k-h