Re: [PATCHSET] 0/3 Dynamic cpufreq governor and updates to ACPI P-state driver

[Arjan van de Ven <arjanv@redhat.com>]

On Thu, Oct 23, 2003 at 11:24:01AM +0300, Alexander Bokovoy wrote:
> On Thu, Oct 23, 2003 at 10:19:44AM +0200, Arjan van de Ven wrote:
> > On Wed, 2003-10-22 at 20:21, Pallipadi, Venkatesh wrote:
> > 
> > > And with the kind of power savings that comes with these frequency
> > > changes, this behaviour 
> > > results in  longer battery life. However, as yet I do not have any
> > > numbers to quantify this gain, 
> > > mainly because I do not have any setup where I can measure actual power.
> > >  
> > 
> > some time ago I did this by using the ACPI method of asking the battery
> > what the current use is at this point in time; it's of course not as
> > exact as a full measurement setup but it's a nice poor mans power watch
> > too ....
> Unfortunately, there is a number of ACPI-enabled BIOSes which report wrong
> battery rate when EST is in action -- they still continue to report a rate
> which corresponds to highest CPU frequency despite the fact that actual
> frequency might be the lowest one.

ok I admit to cheating and not actually using ACPI but talking
to the battery directly based on reverse engineered info (partially based
on the AML, mostly on "if I do this what value changes" ;)