Re: power increase issue on light load

From: Alex,Shi
Date: Sun Jul 03 2011 - 20:45:38 EST


On Sat, 2011-07-02 at 02:00 +0800, Nikhil Rao wrote:
> Hi Ming,
>
> On Thu, Jun 30, 2011 at 10:44 PM, Ming Lei <tom.leiming@xxxxxxxxx> wrote:
> > Hi,
> >
> > On Thu, Jun 23, 2011 at 10:43 AM, Alex,Shi <alex.shi@xxxxxxxxx> wrote:
> >> commit c8b281161dfa4bb5d5be63fb036ce19347b88c63 causes light load
> >> benchmark use more than 10% system power on platform NHM-EP and laptop
> >> Thinkpad T410 etc. The benchmarks are specpower and bltk office.
> >>
> >> I tried to track this issue, but only find deep C sate time reduced
> >> much, about from 90% to 30~40%, the C0 or C1 state increase much on
> >> different machines.
> >>
> >> Powertop just hints RES interrupts has a bit more. but when I try "perf
> >> probe native_smp_send_reschedule". I didn't find much.
> >
> > I see the problem on -rc5 in my T410 too, the fan has been ringing always
> > and powertop reports "Wakeups-from-idle per second : 508.6".
> >
>
> Thanks for reporting this issue. Looks like the increased resolution
> has a negative impact on power savings balance. I'm looking into this
> issue based on Alex's data, but If you can give a trace or something
> that I can work with it will be really helpful.

Ops, I didn't aware that my evolution didn't send out the trace code to
you, until this e-mail. I just resend them and it should be OK this
time. Please check it and give me a response.
Thanks!

>
> -Thanks,
> Nikhil


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