Re: high load with usb device

[Avi Kivity <avi@redhat.com>]

  On 09/14/2010 08:51 AM, Michael Tokarev wrote:
> 12.09.2010 13:26, Avi Kivity пишет:
>>   On 09/10/2010 07:17 PM, Michael Tokarev wrote:
>>> Note the changed subject line.
>>>
>>> I just did a few tests with linux guest (amd64 2.6.35 kernel).
>>>
>>> And it shows the same behavour as win7 (unlike winXP), namely,
>>> high host CPU load when guest is idle.
>> Not for me - F12 idle guest takes 3.5% cpu.
>>
>> What does 'top' in the guest show now?  Connect with ssh to avoid
>> triggering the GUI.
> Guest:
> Cpu(s):  0.0%us,  0.0%sy,  0.0%ni,100.0%id,  0.0%wa,  0.0%hi,  0.0%si,  0.0%st
>
> Host:
> Cpu(s):  5.3%us,  6.7%sy,  0.0%ni, 88.0%id,  0.0%wa,  0.0%hi,  0.0%si,  0.0%st
>    PID USER      PR  NI  VIRT  RES  SHR S %CPU %MEM    TIME+  COMMAND
> 25685 mjt       20   0 1074m 109m 4652 S   19  1.9   0:29.03 qemu-system-x86
>
> So it appears it's the qemu process that's doing something,
> after all.  Is there a way to compile it with profiling
> information?  I tried, but it does not compile: it uses
> -fomit-frame-pointer which is not compatible with -p[g],
> but when removing -fo-f-p it complains about assembly.
>
>

Really, 'perf top' should have shown what qemu was doing.  I don't have 
a lot of experience with profiling userspace, copying linux-perf-users 
for tips.

-- 
error compiling committee.c: too many arguments to function