On 07/18/2012 11:04 AM, Cole Robinson wrote:
On 07/18/2012 11:17 AM, Orion Poplawski wrote:
> On 07/17/2012 04:50 PM, Orion Poplawski wrote:
>> While staring at top on my SL6 kvm server waiting for it to crash, I noticed
>> that my idle Fedora kvm guests appear to be consuming between 8-12% cpu while
>> my idle SL6 guests appear to be consuming between 0.3-2% cpu as shown in the
>> qemu-kvm processes in top. In fact I have a Fedora 17 instance running now
>> with nothing but kernel processes and the qemu-kvm process still shows it
>> using 7-8% cpu.
>>
>> Does anyone have any insight as to why this would be the case?
>>
>
> It appears that toggling the Autosuspend for USB device QEMU USB Tablet [QEMU
> 0.12.1] tunable has a big effect and brings it in line with SL6.
>
> SL6:
> usb 1-1: Product: QEMU USB Tablet
> input: QEMU 0.12.1 QEMU USB Tablet as
> /devices/pci0000:00/0000:00:01.2/usb1/1-1/1-1:1.0/input/input4
> generic-usb 0003:0627:0001.0001: input,hidraw0: USB HID v0.01 Pointer [QEMU
> 0.12.1 QEMU USB Tablet] on usb-0000:00:01.2-1/input0
>
> # cat /sys/devices/pci0000:00/0000:00:01.2/usb1/1-1/power/autosuspend
> 2
> # cat /sys/devices/pci0000:00/0000:00:01.2/usb1/1-1/power/level
> auto
>
> F17:
> [ 3.015642] usb 1-1: Product: QEMU USB Tablet
> [ 3.117125] input: QEMU 0.12.1 QEMU USB Tablet as
> /devices/pci0000:00/0000:00:01.2/usb1/1-1/1-1:1.0/input/input3
> [ 3.117827] generic-usb 0003:0627:0001.0001: input,hidraw0: USB HID v0.01
> Pointer [QEMU 0.12.1 QEMU USB Tablet] on usb-0000:00:01.2-1/input0
>
> # cat /sys/devices/pci0000:00/0000:00:01.2/usb1/power/autosuspend
> 2
> # cat /sys/devices/pci0000:00/0000:00:01.2/usb1/1-1/power/level
> on
>
> So it appears that SL6 is setting to auto automatically, but Fedora is not. I
> wonder why.
>
Hmm, could you please open a bug for that? I guess against F17 qemu for now,
might be kernel or udev though. I think this is a regression from previous
releases, tablet autosuspend is supposed to work out of the box.
Thanks,
Cole
Filed against udev since that is where it was fixed in EL6.
https://bugzilla.redhat.com/show_bug.cgi?id=841368
--
Orion Poplawski
Technical Manager 303-415-9701 x222
NWRA, Boulder Office FAX: 303-415-9702
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http://www.nwra.com