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SubjectRe: 2.6.13-rc3 Battery times at 100/250/1000 Hz = Zero difference
On Fri, 22 Jul 2005 16:48:55 +0200 Pavel Machek wrote:
.......Jesper Juhl wrote
> > Ok, so with an idle machine, different HZ makes no noticeable
> > difference, but I'd suspect things would be different if the machine
> > was actually doing some work.
> > Would be more interresting to see how long it lasts with a light
> > load and with a heavy load.
> No, I do not think so. Biggest difference should be on completely idle
> machine where ACPI can utilize low power states.
> Can you check that C3 is utilized? Unloading usb modules may be
> neccessary...

I've been reading/checking up on this the last four hours since I
had a nagging suspicion that the CPU indeed didn't enter a sleep
state. With all the abbreviations in the ACPI field (S1, C1, P1 etc)
it killed a fair amount of brain cells, but I'd still call faul on this:

from /var/log/kernel
[powernow-k8 module loads processor module which says]
ACPI: CPU0 (power states: C1[C1])

and catting /proc/acpi/processor/CPU0/power gives
active state: C1
max_cstate: C8
bus master activity: 00000000
*C1: type[C1] promotion[--] demotion[--] latency[000] usage[02998796]

/sys/module/processor/parameters/max_cstate says 8
/sys/module/processor/parameters/bm_history says 4294967295

So I'm a bit baffled that no C2/C3 turns up. I've done a test-compile
with all of ACPI in kernel instead of as modules, but there was no

I'll unload the whole USB-module part and boot without loading them, but
will it matter? Please provide more details about how to debug this
(very confusing) field.

Mats Johannesson
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