Re: kvm very slow

[Ulrich Schreiner <ulrich.schreiner-sZDnKEZIvs8b1SvskN2V4Q@public.gmane.org>]

dmesg|grep kvm

SELinux: initialized (dev kvmfs, type kvmfs), uses genfs_contexts
kvm: emulating exchange as write

now booting into a F7 image, after the system is ready (and in idle):

top
   PID USER      PR  NI  VIRT  RES  SHR S %CPU %MEM    TIME+  COMMAND
14917 root      20   0  332m  71m  66m S    6  0.9   1:17.05 qemu-kvm
14954 root      20   0 14552 1072  812 R    0  0.0   0:00.01 top
     1 root      20   0 10320  680  572 S    0  0.0   0:02.02 init

kvm_stat (snapshot):

kvm statistics

  exits        12254399   79079
  halt_exits     326543    4632
  invlpg              0       0
  io_exits      6539798   74320
  irq_exits       43523      29
  irq_window       4984       0
  mmio_exits    1319016       0
  pf_fixed      3140955      56
  pf_guest       448187       6
  request_irq         0       0
  signal_exit     39728       0
  tlb_flush       29511      31

when logging into the virtual machine (via ssh) the virtual world is 
very slow: i set the time with "ntpdate" and wait exact one minute in 
reality. in the virtual image only 24sec are gone!

and everything else in the image is really slow.

Avi Kivity schrieb:
> Ulrich Schreiner wrote:
>> hi,
>>
>> im using a 64 bit fedora7 system with a quad-core processor to host
>> multiple virtual machines.
>>
>> my current kernel is:
>>
>> Linux testserver 2.6.22.1-27.fc7 #1 SMP Tue Jul 17 17:19:58 EDT 2007
>> x86_64 x86_64 x86_64 GNU/Linux
>>
>> (now there is a 2.6.22.1-33.fc7 to download, but i think it is not the
>> point here).
>>
>> i installed
>>
>>   kvm.x86_64: 31-1.fc8
>>
>> because of a crash i reported as a bug with the older kvm module.
>>
>> this system starts a F7 image with the following command:
>>
>> /usr/bin/qemu-kvm   -net nic,macadr=52.54.00.12.34.57   -net 
>> tap,script=./ifup.py,ifname=tap0
>>   -hda /var/qemu/vm_images/F7image.img   -boot c: -m 512 -vnc :2 -k de
>>
>> inside the image there is fedora 7, but a 32bit system.
>>
>> almost everything works (reboot hangs), but the system is extremely
>> slow! the clock inside the system is extremely slow: every *virtual*
>> second in the image is about two or more seconds in the *real* world.
>>   
> 
> Is there anything in dmesg?  What does 'top' report?  What does kvm_stat 
> show?
> 


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