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CapnStank 09-13-2010 12:43 PM

Need help extending battery life
 
I've started running Fedora 13 as a dual boot option on my custom built laptop and notice that my battery life runs out in less than an hour... EDIT: After a bit of research from the OEM I found that it is a Compal laptop.

The computer is dual booted with Windows which gets well over three hours so I know its a configuration issue with the laptop.

The only real information I can provide is from PowerTOP
Code:

Cn                Avg residency      P-states (frequencies)
C0 (cpu running)        ( 7.2%)        2.67 Ghz    3.6%
polling          1.0ms ( 0.0%)        2.67 Ghz    0.0%
C1 mwait          0.0ms ( 0.0%)        2.14 Ghz    0.0%
C2 mwait          0.6ms (11.5%)        1.60 Ghz    0.3%
C6 mwait          2.2ms (81.2%)          800 Mhz    96.2%

Wakeups-from-idle per second : 574.7    interval: 10.0s
Power usage (5 minute ACPI estimate) :  62.4 W (0.6 hours left)

Top causes for wakeups:
  37.9% (264.0)    <kernel core> : hrtimer_start_range_ns (tick_sched_timer)
  21.4% (149.1)      <interrupt> : iwlagn
  15.4% (106.9)  plugin-containe : hrtimer_start_range_ns (hrtimer_wakeup)
  11.5% ( 80.0)      <interrupt> : extra timer interrupt
  7.3% ( 50.6)      <interrupt> : PS/2 keyboard/mouse/touchpad
  1.1% (  8.0)    <kernel core> : hrtimer_start (tick_sched_timer)

As you can see the hrtimer_start_range_ns is doing far too many wakeups. My google researching shows that it is part of Hyperthreading and is a known issue with the kernal but is there anything I can do for a workaround to make it run longer?

I can provide any further information if required.

Bryanlee 09-14-2010 11:54 PM

I believe you can turn off hyper threading in your bios. That's not an ideal solution but it should help with battery life. There are quite a few other reports of this same problem.

CapnStank 09-15-2010 12:40 PM

Yeah, my research has shown that its a bug in the Kernal but I was unable to find if there were any feasible workarounds. If I disable hyperthreading then my Windows boot will suffer so I'd like to avoid that.

Thanks though!

John VV 09-15-2010 01:36 PM

? have you turned off unused services ???
http://www.mjmwired.net/resources/mjm-services-f13.html

are you using compiz-fusion ?
if so uninstall it from a laptop

have you used the "power management" tool

is this a Gnome or KDE fedora 13 ?

have you scaled back on the cpu frequency ?

CapnStank 09-17-2010 06:24 PM

Quote:

Originally Posted by John VV (Post 4098526)
? have you turned off unused services ???
http://www.mjmwired.net/resources/mjm-services-f13.html

are you using compiz-fusion ?
if so uninstall it from a laptop

have you used the "power management" tool

is this a Gnome or KDE fedora 13 ?

have you scaled back on the cpu frequency ?

1) I set my services as that page recommends, there were quite a few changes I needed to make, thanks.

2) I've removed compiz-fusion

3) By "power management tool" I assume you mean the tools for setting screen dimming, when to shut off hard disks/screen etc.? If so yes.

4) I'm using a Gnome fedora 13.

5) The CPU is set to On Demand at all times. It sits at 800MHz >90% of the time.

I'll report back with the power usage after I get a bit of sample data. Thanks for the help!


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