Re: [new] event mode on speedstep-smi.

[Dominik Brodowski <linux@brodo.de>]

On Fri, Sep 05, 2003 at 08:40:11AM +0900, Hiroshi Miura wrote:
> At Thu, 4 Sep 2003 17:30:13 +0200,
> Ducrot Bruno wrote:
> > 
> > > perf_level:  high 16bit is 0x07d0. this is 2000 in decimal.
> > > I think this means polling interval is 2000ms.
> > > 
> > > This code is based on my original one.
> > > Ducrot, How about this?
> > > 
> > 
> > I don't understand the real use for.  Does this permit
> > to switch from performance to powersave when plug in/out ac?
> > If yes, you can have the exact same behaviour via acpi and acpid,
> > with an interrupt driven approach instaead of just polling.
> 
> Yes, now this only switch when plug in/out ac.
> I am also using acpi/acpid staff to switch it.
> My posted code is now only experimental.
> 
> BTW, I want to understand Enhanced Intel SpeedStep Technology.
> 
> I don't know whether 440MX based M-Pentium III-(M) supports 
> EIST or not, but I have tried to switch to demand based switching mode. 
> 
> Someone said this is a point feature of EIST.
> At least, M-Pentium-III-(M) (Tullantin) is EIST ready.
> 
> If SMI interface supported EIST,  I think something 'polling' may be needed.
> My code is to try this. I am now looking for EIST function call on SMI.

I _think_ that within EIST the demand should be detected by the kernel
based on its load. If your assumption is right, though, such a governor 
would be a great addition.

	Dominik