Messages in this thread |  | | From | "Kimon Berlin" <> | Date | Fri, 10 Jan 1997 10:42:10 +0100 | Subject | Re: APM |
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Hi,
> I did get apm to function, but it wasn't the way i wanted. I set an > inactivity timeout in the bios and after that period of time, the cpu > did indeed downshift. *However*, when the cpu became non-inactive, > the bios did not speed the cpu up. Apparently, the bios was simply > monitoring things like key presses to determine inactivity. I would > like to set it up so that the kernel decides when it is inactive and > when it is not. That way, when left unattended, the cpu could slow > down and speed up according to cpu demand (since there is a great deal > of unattended activity) and not simply user interaction at the > console.
I think you only have power management, not APM. In an APM situation, the kernel would tell the BIOS when to switch between power-saving states. I do not know how much support for APM there is in the kernel (besides an APM option in make config).
> This type of setup may not be possible. The ami bios documentation is > very terse and I find even less documentation for the linux side. >
Use your favorite search engine to look for the APM BIOS spec: Advanced Power Management. (APM) BIOS Interface Specification. Revision 1.1. September 1993. Then take a look at the "CPU idle" and "CPU busy" calls.
Kimon. -- Kimon Berlin - Hewlett-Packard Performance Desktop Computing Operation R&D (BIOS), a spinoff of the Division Formerly Known as GPCD "You can tune a filesystem, but you can't tune a fish" [HP/UX tunefs(1M)]
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