[ltp] T60 power management (fglrx, aticonfig --set-powerstate )

[Nils Kanning]

On Wed, 2006-08-09 at 10:43 +0200, Florian Manschwetus wrote:
> Michael Olbrich wrote:
> > Hi,
> > 
> > On Tue, Aug 08, 2006 at 10:53:42PM +0200, Nils Kanning wrote:
> >> how do you do the core disabling? is it a special kernel feature or a
> >> feature of the centrino_speedstep module?
> >> which kernel do you use?
> > 
> > echo 0 > /sys/devices/system/cpu/cpu1/online
> > 
> > michael
> > 
> at least you can ask tp_smapi how much power you drain from battery
> (cat /sys/devices/platform/smapi/BAT0/power_now)
> i could press it down to arround 16 W with wlan
> (2007 63G)
> florian

after doing
echo 0 > /sys/devices/system/cpu/cpu1/online
/proc/cpuinfo only shows one cpu. however in /proc/acpi/processor there
are still both cpus and CPU1/power always shows C1 (this does not depend
on the state CPU1 was in before disabling it).

furthermore /sys/devices/platform/smapi/BAT0/power_now does not change
if i disable the second core. so i do not gain any power.

here is the output of dmesg (first enabling cpu1):
SMP alternatives: switching to SMP code
Booting processor 1/1 eip 3000
Initializing CPU#1
Calibrating delay using timer specific routine.. 3657.71 BogoMIPS
(lpj=7315437)
CPU: After generic identify, caps: bfe9fbff 00100000 00000000 00000000
0000c1a9 00000000 00000000
CPU: After vendor identify, caps: bfe9fbff 00100000 00000000 00000000
0000c1a9 00000000 00000000
monitor/mwait feature present.
CPU: L1 I cache: 32K, L1 D cache: 32K
CPU: L2 cache: 2048K
CPU: Physical Processor ID: 0
CPU: Processor Core ID: 1
CPU: After all inits, caps: bfe9fbff 00100000 00000000 00000140 0000c1a9
00000000 00000000
Intel machine check architecture supported.
Intel machine check reporting enabled on CPU#1.
CPU1: Intel Genuine Intel(R) CPU           T2400  @ 1.83GHz stepping 08
APIC error on CPU1: 00(40)

(disabling cpu1)
CPU 1 is now offline
SMP alternatives: switching to UP code

nils