Comment 27 for bug 1100843

I used this handy tool to run system call preliminary benchmarks: http://code.google.com/p/byte-unixbench/

 In a nutshell, what I found is a confirmation that live migration does indeed degrade performance on precise KVM.
 I hope the below results help narrow down this critical problem to eventually have it resolved in 12.04 LTS version.

detail results:
Compiled the benchmarking tool and then:
root@sample-vm:~/UnixBench# ./Run syscall

Output:

** before live-migration **
------------------------------------------------------------------------
Benchmark Run: Wed May 01 2013 20:29:54 - 20:32:04
1 CPU in system; running 1 parallel copy of tests
System Call Overhead 4177612.4 lps (10.0 s, 7 samples)
System Benchmarks Partial Index BASELINE RESULT INDEX
System Call Overhead 15000.0 4177612.4 2785.1
                                                                   ========
System Benchmarks Index Score (Partial Only) 2785.1
------------------------------------------------------------------------

** after live-migration **
------------------------------------------------------------------------
Benchmark Run: Wed May 01 2013 20:35:16 - 20:37:26
1 CPU in system; running 1 parallel copy of tests
System Call Overhead 3065118.3 lps (10.0 s, 7 samples)
System Benchmarks Partial Index BASELINE RESULT INDEX
System Call Overhead 15000.0 3065118.3 2043.4
                                                                   ========
System Benchmarks Index Score (Partial Only) 2043.4
------------------------------------------------------------------------

XML domain dump:

  <memory>1048576</memory>
  <currentMemory>1048576</currentMemory>
  <vcpu>1</vcpu>
  <cputune>
    <shares>1024</shares>
  </cputune>
  <os>
    <type arch='x86_64' machine='pc-1.0'>hvm</type>
    <boot dev='hd'/>
  </os>
  <features>
    <acpi/>
  </features>
  <clock offset='utc'/>
  <on_poweroff>destroy</on_poweroff>
  <on_reboot>restart</on_reboot>
  <on_crash>destroy</on_crash>
  <devices>
    <emulator>/usr/bin/kvm</emulator>
    <disk type='file' device='disk'>
      <driver name='qemu' type='qcow2'/>
      <source file='HIDEME'/>
      <target dev='vda' bus='virtio'/>
      <alias name='virtio-disk0'/>
      <address type='pci' domain='0x0000' bus='0x00' slot='0x04' function='0x0'/>
    </disk>
    <disk type='file' device='cdrom'>
      <driver name='qemu' type='raw'/>
      <source file='HIDEME'/>
      <target dev='hda' bus='ide'/>
      <readonly/>
      <alias name='ide0-0-0'/>
      <address type='drive' controller='0' bus='0' unit='0'/>
    </disk>
    <controller type='ide' index='0'>
      <alias name='ide0'/>
      <address type='pci' domain='0x0000' bus='0x00' slot='0x01' function='0x1'/>
    </controller>