Re: [gpm] Bring back cpu frequency scaling options, heres why:

[Richard Hughes <hughsient gmail com>]

On Fri, 2008-10-03 at 15:07 +1000, James . wrote:
> It is a surprise to see cpu frequency scaling options completely taken
> off gnome-power-manager for 2.24 release. I think this is a rash and
> uncalled for decision. 

Thanks.

> My previous setup, gnome-power-manager 2.22 worked fine using the
> policy_ac and policy_battery settings in gconf to change from
> "performance" to "ondemand" when my laptop is on battery. Obviously,
> since the removal of this code in 2.24, that no longer works, and now
> I am forced to use various ugly acpi.sh hacking scripts etc to get the
> same effect- a solution far less elegant than that which came with
> gnome-power-manager 2.22. 

Why do you want to use performance? I've seen the profiling and done the
measurement myself, and the only thing performance is good for is
heating the planet and for very specialist low latency workloads.

> I understand the ideas laid out in
> http://www.advogato.org/person/mjg59/diary.html?start=123 which seems
> to be the rationale for removing the code. But its funny how it
> mentions that the scaling governor that should be used is "ondemand",
> meaning that there is still much purpose for reducing the cpu
> frequency as long as its done during idle.

Sure, if the CPU needs ramping up, then ondemand ramps up the CPU until
we are idle again, and then it ramps down.

> As a final note, for those that are updating to the latest version of
> gnome, they may be unaware that such an important feature has been
> removed. Maybe you should mention it on gnome's 2.24 page.

The feature has been hidden in the GUI for two releases. If you were
using it, then you were changing stuff in GConf. Hardly a user visable
regression.

Richard.