From mboxrd@z Thu Jan  1 00:00:00 1970
From: Marcelo Tosatti <mtosatti@redhat.com>
Subject: Re: KVM power usage - high wakeup rates
Date: Thu, 19 Jun 2008 15:26:28 -0300
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Cc: kvm@vger.kernel.org
To: Haydn Solomon <haydn.solomon@gmail.com>
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On Thu, Jun 19, 2008 at 01:29:39AM -0400, Haydn Solomon wrote:
> Hi List,
> 
> When testing power usage of a windows xp guest using powertop utility,
> I'm noticing high wakeup rates. The following is the output of
> powertop for an idle windows xp guest.
> 
> 
> ==============================
> ===========================
> Wakeups-from-idle per second : 2716.6   interval: 10.0s
> no ACPI power usage estimate available
> 
> Top causes for wakeups:
>   52.4% (2434.4)   qemu-system-x86 : sys_timer_settime (posix_timer_fn)
>   21.5% (996.7)   qemu-system-x86 : __kvm_migrate_pit_timer (pit_timer_fn)
>   15.0% (697.4)       <interrupt> : extra timer interrupt
>    4.9% (227.6)      <kernel IPI> : Rescheduling interrupts
>    1.6% ( 72.9)   USB device  6-2 : Optical USB Mouse (Logitech)
>    1.3% ( 61.7)       <interrupt> : nvidia
>    1.3% ( 59.0)       <interrupt> : uhci_hcd:usb4, uhci_hcd:usb6, HDA Intel
> ===================================================================
> 
> I'm getting similar values when running a Fedora 9 guest.

What difference do you see when closing the VNC client ?